125 results on '"Kossi K"'
Search Results
2. Children hydrocephalus in Togo: etiologies, treatment, and outcomes
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Kpélao, Essossinam, primary, Ahanogbé, Kodjo M. Hobli, additional, Egu, Komi, additional, Doléagbénou, Agbéko K, additional, Moumouni, Abd El Kader, additional, Sossoukpe, Senamé, additional, Ségbédji, Kossi K., additional, Bakondé, H. EssoSolim, additional, Lawson, Dzidoula, additional, Abaltou, Bawoubadi, additional, Abdoulaye, Hima-Maïga, additional, and Békéti, Katanga A., additional
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- 2022
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3. Children hydrocephalus in Togo: etiologies, treatment, and outcomes
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Essossinam Kpélao, Kodjo M. Hobli Ahanogbé, Komi Egu, Agbéko K Doléagbénou, Abd El Kader Moumouni, Senamé Sossoukpe, Kossi K. Ségbédji, H. EssoSolim Bakondé, Dzidoula Lawson, Bawoubadi Abaltou, Hima-Maïga Abdoulaye, and Katanga A. Békéti
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Surgery ,Neurology (clinical) - Abstract
Background: Hydrocephalus is frequent in sub-Saharan African countries. The postinfectious hydrocephalus tends to decrease. The objective of this study was to identify the etiologies and outcomes of hydrocephalus. Methods: This was a retrospective study of hydrocephalus cases (0–15 years old) treated in the neurosurgery unit of the Sylvanus Olympio Hospital in Lomé over 10 years (2012–2021). At 1 year, the evolution distinguished in two categories: (1) Good psychomotor development: no delay in the acquisition of walking, language, and school. (2) Psychomotor delay: delay in the acquisition of walking, language, and school. Results: We reported 305 children treated for hydrocephalus representing 1.8% of all neurosurgery unit patients and 34.2% of pediatric pathologies. There was a male predominance (60.6%). We noted second degree consanguinity in 8.5%. The positive maternal serologies were HIV (12.4%), syphilis (8.2%), and toxoplasmosis (2.6%). A malaria episode had been treated during the first trimester in 36.7% of the mothers. The main clinical sign of hydrocephalus was 91.5% of Macrocephalus. Congenital Malformafions were the most common etiologies of hydrocephalus (68.5%). Ventriculoperitoneal shunt was the main surgical method used and 16 deaths were recorded. The medium-term evolution (1 year) was evaluated in 36.1% and noted 61.8% of psychomotor retardation. Conclusion: This study confirms the trend of the predominance of congenital causes of hydrocephalus in Africa, even if maternal infections can be involved in the development of some of them. The morbimortality of this pathology remains important, especially concerning neurocognitive outcomes.
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- 2022
4. Valuation of hybrid financial and actuarial products in life insurance by a novel 3-step method
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Deelstra, Griselda, Devolder, Pierre, Gnameho, Kossi K., and Hieber, Peter
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Sciences actuarielles - Abstract
info:eu-repo/semantics/published
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- 2020
5. Derivation of a GIS-Based Flood Hazard Map in Peri-Urban Areas of Greater Lomé, Togo (West Africa)
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Têtou-Houyo Blakime, Kossi Komi, Kossi Adjonou, Atsu K. Dogbeda Hlovor, Kodjovi Senanou Gbafa, Peter B. Oyedele, Botolisam Polorigni, and Kouami Kokou
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climate change ,flood hazard ,analytic hierarchy process ,geographic information system ,Greater Lomé ,Togo ,Geography. Anthropology. Recreation ,Social Sciences - Abstract
In Togo, and especially in the peri-urban areas of Greater Lomé, flood hazards and their effects on communities and ecosystems have increased in recent years due to global changes. This is predominantly due to increasing urbanization and the changing climate. This study explores the application of remote sensing, geographic information system (GIS) and analytical hierarchy processes (AHP) for flood hazard mapping in Greater Lomé. Maps of seven (7) drivers of flood hazards, namely flow accumulation, rainfall intensity, geology and soil, land use, slope, elevation and distance from the drainage network, were prepared by integrating remote sensing data into a GIS environment. The weight of each factor was estimated via the AHP method and used in the estimation of the flood hazard index (FHI). The results show that there is a high or very high susceptibility of flooding in 53.4% of the Greater Lomé suburbs, while there is a moderate to low susceptibility of flooding in about 46.59% of it, and 0.01% of the study area. The generated map is a useful tool for decision-makers and practitioners in charge of flood risk and disaster management when developing plans to reduce the risk of both current and future floods in the study area.
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- 2024
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6. Dynamics of Built-Up Areas and Challenges of Planning and Development of Urban Zone of Greater Lomé in Togo, West Africa
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Têtou-Houyo Blakime, Kossi Adjonou, Kossi Komi, Atsu K. Dogbeda Hlovor, Kodjovi Senanou Gbafa, Jean-Bosco Benewinde Zoungrana, Botolisam Polorigni, and Kouami Kokou
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urban sprawl ,residential areas ,urban planning ,Greater Lomé ,Togo ,Agriculture - Abstract
The expansion of African cities leads to the occupation of peripheral urban areas without respecting planning rules. The Greater Lomé (Togo) is no exception to this phenomenon of high-speed horizontal spreading, which causes recurrent flooding. The objective of this research is to understand the spatio-temporal changes in the dynamics of built-up areas in Greater Lomé. The methodology used is based on the analysis of Landsat images from the years 2007, 2012, 2016, and 2020 coupled with direct field observations and a literature review. The results showed an increase in residential areas to the detriment of the other land use/cover types. Estimated at 15,481 ha in 2007, the built-up area reached 35,521 ha in 2020, an increase of 33% to the detriment of vegetation and cultivation areas. This increase was marked by constructions in the floodplain of the Zio River. The field surveys revealed an increase in the density of most of the agglomerations. From 1863 ha in 2007, they increased to 14,485 ha in 2020, an increase of 12,622 ha or approximately 33%. These results indicate that attention needs to be paid to both the planning and control of the development of spaces in the outlying areas of Greater Lomé.
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- 2024
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7. Chirurgie endoscopique de l’appareil urinaire au CHU Sylvanus Olympio : Bilan, analyse des potentialities biomedicales et ressources humaines au Togo
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Anoukoum, T., Bouwassi, K.D.C., Edoh-Kossi, K, Goda-Koussema, L.K., Kpatcha, M, Tengue, K, Tomta, K, and Attipou, K
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Endoscopie, urologie, biomédical, maintenance, plateau, technique, personnel, Afrique - Abstract
Après un bilan assez limite, des cinq (05) dernières années des activités de chirurgie endoscopique sur l’appareil urinaire, au CHU SO, cette étude analyse les résultats, fait l’état des lieux du matériel endoscopique disponible, des ressources biomédicales au Togo puis situe la place de la maintenance biomédicale dans la chaîne des soins. Le but de cette étude étant de souligner les insuffisances et les points forts de cette technique au plan national puis d’accroître cette spécificité chirurgicale très bénéfique, au plan économie et de durée de séjour réduit pour la prise en charge des patients, malgré le système d’entretien énorme sans cesse croissant au plan de l’entretien biomédical. Le Togo compte 9 services publics de maintenance biomédicale dont un au CHU SO et un atelier biomédical privé à Lomé plus ou moins fonctionnel. En matière de ressources humaines, on dénombre au Togo quatre (4) ingénieurs biomédicaux, douze (12) techniciens biomédicaux et une dizaine d’agents de maintenance. Il existe dans la plupart de ces structures une inadéquation entre les besoins et les ressources biomédicales, marquée par une organisation inadaptée et/ou insuffisante de la maintenance biomédicale. Ainsi, la formation initiale, et/ou continue et l’implication des techniciens biomédicaux dans le processus d’acquisition de matériels (achats et dons) s’avèrent nécessaires.Mots clés : Endoscopie, urologie, biomédical, maintenance, plateau, technique, personnel, Afrique.
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- 2016
8. Design and Development of Large-Band Dual-MSFA Sensor Camera for Precision Agriculture
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Vahid Mohammadi, Pierre Gouton, Matthieu Rossé, and Kossi Kuma Katakpe
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multispectral filter array ,multispectral camera ,snap-shot spectral camera ,color shade technology ,demosaicking ,Chemical technology ,TP1-1185 - Abstract
The optimal design and construction of multispectral cameras can remarkably reduce the costs of spectral imaging systems and efficiently decrease the amount of image processing and analysis required. Also, multispectral imaging provides effective imaging information through higher-resolution images. This study aimed to develop novel, multispectral cameras based on Fabry–Pérot technology for agricultural applications such as plant/weed separation, ripeness estimation, and disease detection. Two multispectral cameras were developed, covering visible and near-infrared ranges from 380 nm to 950 nm. A monochrome image sensor with a resolution of 1600 × 1200 pixels was used, and two multispectral filter arrays were developed and mounted on the sensors. The filter pitch was 4.5 μm, and each multispectral filter array consisted of eight bands. Band selection was performed using a genetic algorithm. For VIS and NIR filters, maximum RMS values of 0.0740 and 0.0986 were obtained, respectively. The spectral response of the filters in VIS was significant; however, in NIR, the spectral response of the filters after 830 nm decreased by half. In total, these cameras provided 16 spectral images in high resolution for agricultural purposes.
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- 2023
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9. Dosimetrie et radioprotection des patients lors des examens tomodensitomtriques au Chu Sylvanus Olympio (CHU-SO) de Lomé (Togo)
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Tchaou, M, Sonhaye, L, Agoda-koussema, LK, Amadou, A, Adambounou, K, Kolou, B, Teko-Agbo, E, Edoh-Kossi, K, Magnangou, A, and N'Dakena, K
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Dosimétrie, radioprotection, tomodensitométrie, crâne, Lomé - Abstract
Méthodologies : Etude rétrospective des rapports de doses de 660 scanners de la tête,du thorax, de l’abdomen et du pelvis des adultes de plus 15 ans réalisés au pavillonscanner du CHU-SO de juillet à décembre 2011.Résultats : La tête était la région la plus explorée (565), suivie de thorax (43), del’abdomen (33) et enfin du pelvis (19). On notait une prédominance masculine avec unratio de 1,5 homme pour une femme. La tranche d’âge la plus représentée était latranche 46-51 ans. Les CTDI vol moyens étaient de 61,5 mGy pour les scanners de latête, 8,7mGy pour le thorax, 70,9 mGy pour l’abdomen et 2,8 mGy pour le pelvis. LesDLP moyens étaient de 1850mGy/cm pour les scanners de la tête, 281,8 mGy/cm pourle thorax, 476,2 mGy/cm pour l’abdomen et 351,6 pour le pelvis. Quatre cent quarantequatrescanners (78,58%) de la tête avaient une dose supérieure à 2,2 mSv. Pour lesscanners du thorax, 4 (9,30%) dépassaient les 8,5 mSv, 24,24% (8/33) des scanners del’abdomen dépassaient 9,8 mSv et 47,37%(9/19) des scanners du pelvis avaient uneexposition supérieure à 7,2 mSv.Conclusion : Il ressort de notre étude que les doses délivrées aux patients lors desexamens TDM sont supérieurs aux NRD françaises et européennes, surtout pour la tête.Mots clés : Dosimétrie, radioprotection, tomodensitométrie, crâne, Lomé.ABSTRACTMethodology: A retrospective study doses reports of 660 scans of the head, thorax,abdomen and pelvis of adults over 15 years made in the CHU-SO from July toDecember 2011.Results: The head was the most explored region (565), followed by chest (43), abdomen(33) and the pelvis (19). We noted a male predominance with a male ratio of 1.5 for awoman. The most represented age group was the 46-51 year bracket. The CTDI volmeans were 61.5 mGy for scanners of the head, thorax 8,7mGy, 70.9 mGy for theabdomen and 2.8 mGy for the pelvis. The DLP means were 1850mGy / cm for scannersof the head, 281,8mGy / cm for the thorax, 476,2mGy / cm, and 351.6 for the abdomenand pelvis. Four hundred forty-four scanners (78.58%) of the head had a dose higherthan 2.2 mSv. For scanners chest, 4 (9.30%) exceeded 8.5 mSv, 24.24% (8/33) of theabdomen scanners exceeded 9.8 mSv and 47.37% (9/19) of pelvic scanners were greaterthan 7,2mSv exposure.Conclusion: Our study shows that patient dose during CT examinations are superior tothe French and European DRLs, especially for the head.Keywords: Dosimetry, radioprotection, CT, head, Lome.
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- 2015
10. Urban Governance and Sanitation in the Peri-Urban Commune of Agoè-Nyvé 6 in Togo: Diagnosis of the Sanitation System in Adétikopé
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Efui Holaly Gbekley, Koko Zébéto Houedakor, Kossi Komi, Sossawè Poli, Djiwonou Koffi Adjalo, Ablam Nyakpo, Ayayivi Mensah Ayivigan, Abdourahamane Aissa Ghanny Vanessa Ali, Kossiwa Zinsou-Klassou, and Pèssiezoum Adjoussi
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urban governance ,sustainable development ,wastewater management ,Adétikopé ,Togo ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
In African cities, the ever-increasing production of wastewater and excreta poses a major management problem. The aim of this study was to take stock of wastewater and excreta management in Adétikopé in the commune of Agoè-Nyivé 6. This was a cross-sectional, descriptive study of the knowledge, attitudes and practices of the population of the locality of Adétikopé in terms of wastewater and excreta management, which took place from August 2022 to July 2023. It involved 5256 households in 12 villages in the locality of Adétikopé and was carried out via a field survey, interviews, observations and documentary research. The results showed that 72.60% of respondents were women. The majority of households (85.62%) had latrines, 66.40% of which had never been emptied. The remainder used a mechanical emptying truck (5.48%). Households without latrines (14.38%) defecate with neighbors (14.28%) in the open (66.67%) and in public latrines (19.05%). The same applies to wastewater from cooking, washing and dishwashing, which is most often dumped on the public highway (78.77%). Wastewater is a breeding ground for mosquitoes that cause malaria, which is the most common disease in the area. The results of this study show that wastewater and excreta are managed by most concessions in an unhealthy way and discharged into the environment. It is important to step up public awareness campaigns on the harmful consequences of poor wastewater and excreta disposal.
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- 2023
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11. Analysis of extreme rainfall in Oti River Basin (West Africa)
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Komi S. Klassou and Kossi Komi
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climate change ,extreme rainfall ,oti river basin ,togo ,trends ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 - Abstract
Understanding how extreme rainfall is changing locally is a useful step in the implementation of efficient adaptation strategies to negative impacts of climate change. This study aims to analyze extreme rainfall over the middle Oti River Basin. Ten moderate extreme precipitation indices as well as heavy rainfall of higher return periods (25, 50, 75, and 100 years) were calculated using observed daily data from 1921 to 2018. In addition, Mann–Kendall and Sen's slope tests were used for trend analysis. The results showed decreasing trends in most of the heavy rainfall indices while the dry spell index exhibited a rising trend in a large portion of the study area. The occurrence of heavy rainfall of higher return periods has slightly decreased in a large part of the study area. Also, analysis of the annual maximum rainfall revealed that the generalized extreme value is the most appropriate three-parameter frequency distribution for predicting extreme rainfall in the Oti River Basin. The novelty of this study lies in the combination of both descriptive indices and extreme value theory in the analysis of extreme rainfall in a data-scarce river basin. The results are useful for water resources management in this area. HIGHLIGHTS Observed trends of extreme rainfall in the Oti River Basin from 1921 to 2018.; The occurrence of heavy rainfall of higher return periods has slightly decreased in a major part of the study area.; Consecutive dry days index has increased in a large part of the study area.; Generalized Extreme Value is the best three parameter distribution for analyzing the frequency of extreme rainfall in the Oti River Basin.;
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- 2021
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12. An Integrated 700–1200-MHz Class-F PA With Tunable Harmonic Terminations in 0.13-$\mu$m CMOS
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Sessou, Kossi K., primary and Neihart, Nathan M., additional
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- 2015
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13. Onchocerca volvulus-specific antibody and cellular responses in onchocerciasis patients treated annually with ivermectin for 30 years and exposed to parasite transmission in central Togo
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Saskia I. Johanns, Richard G. Gantin, Bawoubadi Wangala, Kossi Komlan, Wemboo A. Halatoko, Meba Banla, Potchoziou Karabou, Adrian JF Luty, Hartwig Schulz-Key, Carsten Köhler, and Peter T. Soboslay
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Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Background Annual mass drug administrations (MDA) of ivermectin will strongly reduce Onchocerca volvulus microfilariae (mf) in the skin and in the onchocerciasis patients’ eyes. Ivermectin treatment will also affect the expression of immunity in patients, such that activated immune defenses may help control and contribute to clearance of mf of O. volvulus. Longitudinal surveys are a prerequisite to determining the impact of ivermectin on the status of anti-parasite immunity, notably in risk zones where parasite transmission and active O. volvulus infections persist. Methodology/Principal findings Onchocerciasis patients were treated annually with ivermectin and their Onchocerca volvulus antigen (OvAg) specific IgG and cellular responses were investigated before and at 30 years post initial ivermectin treatment (30yPT). Repeated annual ivermectin treatments eliminated persisting O. volvulus microfilariae (mf) from the skin of patients and abrogated patent infections. The OvAg-specific IgG1 and IgG4 responses were diminished at 30yPT to the levels observed in endemic controls. Prior to starting ivermectin treatment, OvAg-induced cellular productions of IL-10, IFN-γ, CCL13, CCL17 and CCL18 were low in patients, and at 30yPT, cellular cytokine and chemokine responses increased to the levels observed in endemic controls. In contrast, mitogen(PHA)- induced IL-10, IFN-γ, CCL17 and CCL18 cellular production was diminished. This divergent response profile thus revealed increased parasite antigen-specific but reduced polyclonal cellular responsiveness in patients. The transmission of O. volvulus continued at the patients’ location in the Mô river basin in central Togo 2018 and 2019 when 0.58% and 0.45%, respectively, of Simulium damnosum s.l. vector blackflies carried O. volvulus infections. Conclusions/Significance Repeated annual ivermectin treatment of onchocerciasis patients durably inhibited their patent O. volvulus infections despite ongoing low-level parasite transmission in the study area. Repeated MDA with ivermectin affects the expression of immunity in patients. O. volvulus parasite-specific antibody levels diminished to levels seen in infection-free endemic controls. With low antibody levels, antibody-dependent cellular cytotoxic responses against tissue-dwelling O. volvulus larvae will weaken. O. volvulus antigen inducible cytokine and chemokine production increased in treated mf-negative patients, while their innate responsiveness to mitogen declined. Such lower innate responsiveness in elderly patients could contribute to reduced adaptive immune responses to parasite infections and vaccines. On the other hand, increased specific cellular chemokine responses in mf-negative onchocerciasis patients could reflect effector cell activation against tissue invasive larval stages of O. volvulus. The annual Simulium damnosum s.l. biting rate observed in the Mô river basin was similar to levels prior to initiation of MDA with ivermectin, and the positive rtPCR results reported here confirm ongoing O. volvulus transmission. Author summary Onchocerciasis is a neglected tropical disease, and a major cause of debilitating skin disease and ocular damage that can lead to irreversible blindness. Annual mass drug administrations (MDA) of ivermectin strongly reduces the load of Onchocerca volvulus microfilaria (mf) in the skin and in the patients’ eyes. Evolution of onchocerciasis as a disease is prevented by MDA, but recent studies have shown that O. volvulus transmission has not been completely interrupted. Repeated MDA with ivermectin affects immune responses, such that activated immune defenses may enhance clearance of mf of O. volvulus. Longitudinal surveys are required to determine the impact of ivermectin on the status of immunity, notably in risk zones where parasite transmission and active O. volvulus infections persist. We examined the changes of O. volvulus parasite-specific antibody and cellular immune responsiveness in patients treated annually with ivermectin for 30 years. Treatment prevented patent O. volvulus infections, whilst parasite antigen-specific cytokine and chemokine responses increased but O.volvulus-specific antibody responses declined. Such decreased antibody levels could weaken antibody-dependent cellular cytotoxic responses to infective and tissue-dwelling O. volvulus larvae. Strengthened monocyte attracting and activation regulated chemokine responses could enhance effector cell migration and activation against larval stages of O.volvulus, possibly also eliciting resistance to further parasite infections.
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- 2022
14. Assessing Flood Risk Dynamics in Data-Scarce Environments—Experiences From Combining Impact Chains With Bayesian Network Analysis in the Lower Mono River Basin, Benin
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Mario Wetzel, Lorina Schudel, Adrian Almoradie, Kossi Komi, Julien Adounkpè, Yvonne Walz, and Michael Hagenlocher
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drivers of risk ,risk assessment ,conceptual model ,flood risk ,Benin ,vulnerability ,Environmental technology. Sanitary engineering ,TD1-1066 - Abstract
River floods are a common environmental hazard, often causing severe damages, loss of lives and livelihood impacts around the globe. The transboundary Lower Mono River Basin of Togo and Benin is no exception in this regard, as it is frequently affected by river flooding. To enable adequate decision-making in the context of flood risk management, it is crucial to understand the drivers of risk, their interconnections and how they co-produce flood risks as well as associated uncertainties. However, methodological advances to better account for these necessities in risk assessments, in data-scarce environments, are needed. Addressing the above, we developed an impact chain via desk study and expert consultation to reveal key drivers of flood risk for agricultural livelihoods and their interlinkages in the Lower Mono River Basin of Benin. Particularly, the dynamic formation of vulnerability and its interaction with hazard and exposure is highlighted. To further explore these interactions, an alpha-level Bayesian Network was created based on the impact chain and applied to an exemplary what-if scenario to simulate changes in risk if certain risk drivers change. Based on the above, this article critically evaluates the benefits and limitations of integrating the two methodological approaches to understand and simulate risk dynamics in data-scarce environments. The study finds that impact chains are a useful model approach to conceptualize interactions of risk drivers. Particularly in combination with a Bayesian Network approach, the method enables an improved understanding of how different risk drivers interact within the system and allows for dynamic simulations of what-if scenarios, for example, to support adaptation planning.
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- 2022
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15. An Integrated 700–1200-MHz Class-F PA With Tunable Harmonic Terminations in 0.13-\mum CMOS.
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Sessou, Kossi K. and Neihart, Nathan M.
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EFFICIENCY of power amplifiers , *CMOS integrated circuits , *HARMONIC analysis (Mathematics) , *LONG-Term Evolution (Telecommunications) , *ON-chip transformers - Abstract
A fully integrated class-F power amplifier (PA) with reconfigurable harmonic termination over a wide range of frequencies is presented. Reconfigurability is achieved by utilizing on-chip transformers as part of the output matching network. In addition, a stacked transistor architecture was used to boost the output power. The PA was fabricated in a 0.13-\mum CMOS process and packaged in a 20-pin quad flat no-leads package. It was configured to operate at 700, 900, and 1200 MHz with a maximum measured saturated output power of +\24.6 dBm with a power-added efficiency of 48.3%. The measured gain was 16.5 dB and was flat over the entire bandwidth. The total chip area, including pads, is 1.5 mm\,\times\,1.5 mm. [ABSTRACT FROM AUTHOR]
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- 2015
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16. Development of two loop-mediated isothermal amplification (LAMP) genomics-informed diagnostic protocols for rapid detection of Pantoea species on rice
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Kossi Kini, Issa Wonni, Drissa Silué, and Ralf Koebnik
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Diagnostic protocol ,Loop-mediated isothermal amplification (LAMP) ,Pantoea spp. ,Rice ,Science - Abstract
At least three species of Pantoea are responsible for bacterial blight disease and grain discoloration of rice in Sub-Saharan Africa. Thus, measures need to be taken to limit the pathogens' dispersion and robust diagnostic tools are required for rapid and cheap diagnosis in the field as well as for routine seed certification or control. Therefore, several diagnostic tools such as simplex and multiplex PCR schemes and a semi-selective medium have been developed and are being used. However, the use of these tools is time-consuming, expensive and therefore limited to laboratories that can afford the chemicals. We have therefore developed two isothermal loop amplification (LAMP) protocols, one of which detects all Pantoea species in the genus and another one that is specific for P. ananatis. • The novel LAMP assays allow rapid and sensitive detection of these bacteria. • They will help plant protection services in routine field and laboratory tests especially for monitoring the phytosanitary status of rice seeds.
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- 2021
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17. An Efficient Inoculation Technique to Assess the Pathogenicity of Pantoea Species Associated to Bacterial Blight of Rice
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Kossi Kini, Raoul Agnimonhan, Issa Wonni, and Drissa Silue
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Biology (General) ,QH301-705.5 - Abstract
Bacteria blight diseases of rice due to several genera of pathogenic bacteria are one of the major constraints worldwide for rice production. The disease can be best managed through host plant resistance sources. For most of these bacteria such as Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, Pseudomonas fuscovaginae, Burkholderia glumae, Burkholderia gladioli and Acidovorax avenae subsp. avenae, specific diagnostic techniques that include molecular and pathogenicity tests have been developed. However, for Pantoea spp., information on pathogenicity assay is very limited and protocols used are not uniform. Most authors use the leaf clipping method. In this paper, we describe the protocol for mechanical inoculation of rice seedlings aged 35 days. The method consists of infiltrating bacterial suspensions at concentrations of 108 CFU/ml, with a needleless syringe into the intercellular and interveinal spaces of rice leaves underside at about 4-5 cm below the leaf tip. This method can be used for a standardized pathogenicity assessment, germplasm resistance evaluation for identifying and characterizing resistance sources.
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- 2020
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18. Design of a new multiplex PCR assay for rice pathogenic bacteria detection and its application to infer disease incidence and detect co-infection in rice fields in Burkina Faso.
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Martine Bangratz, Issa Wonni, Kossi Kini, Moussa Sondo, Christophe Brugidou, Gilles Béna, Fatoumata Gnacko, Mariam Barro, Ralf Koebnik, Drissa Silué, and Charlotte Tollenaere
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Medicine ,Science - Abstract
Crop diseases are responsible for considerable yield losses worldwide and particularly in sub-Saharan Africa. To implement efficient disease control measures, detection of the pathogens and understanding pathogen spatio-temporal dynamics is crucial and requires the use of molecular detection tools, especially to distinguish different pathogens causing more or less similar symptoms. We report here the design a new molecular diagnostic tool able to simultaneously detect five bacterial taxa causing important diseases on rice in Africa: (1) Pseudomonas fuscovaginae, (2) Xanthomonas oryzae, (3) Burkholderia glumae and Burkholderia gladioli, (4) Sphingomonas and (5) Pantoea species. This new detection tool consists of a multiplex PCR, which is cost effective and easily applicable. Validation of the method is presented through its application on a global collection of bacterial strains. Moreover, sensitivity assessment for the detection of all five bacteria is reported to be at 0.5 ng DNA by μl. As a proof of concept, we applied the new molecular detection method to a set of 256 rice leaves collected from 16 fields in two irrigated areas in western Burkina Faso. Our results show high levels of Sphingomonas spp. (up to 100% of tested samples in one field), with significant variation in the incidence between the two sampled sites. Xanthomonas oryzae incidence levels were mostly congruent with bacterial leaf streak (BLS) and bacterial leaf blight (BLB) symptom observations in the field. Low levels of Pantoea spp. were found while none of the 256 analysed samples was positive for Burkholderia or Pseudomonas fuscovaginae. Finally, many samples (up to 37.5% in one studied field) were positive for more than one bacterium (co-infection). Documenting co-infection levels are important because of their drastic consequences on epidemiology, evolution of pathogen populations and yield losses. The newly designed multiplex PCR for multiple bacterial pathogens of rice is a significant improvement for disease monitoring in the field, thus contributing to efficient disease control and food safety.
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- 2020
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19. Mansonella perstans, Onchocerca volvulus and Strongyloides stercoralis infections in rural populations in central and southern Togo
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Francois Korbmacher, Kossi Komlan, Richard G. Gantin, Wiyao P. Poutouli, Koffi Padjoudoum, Potchoziou Karabou, Peter T. Soboslay, and Carsten Köhler
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Infectious and parasitic diseases ,RC109-216 - Abstract
Background: Mansonella perstans, Onchocerca volvulus and Strongyloides stercoralis are widespread helminth parasites in the tropics. Their distribution remains difficult to determine as it may change during national disease control programs and with regional mass drug administration (MDA). Epidemiological surveys are of importance to evaluate the geographical distribution of these helminth parasites and the diseases they may cause, however, up to date epidemiological evaluations on M. perstans and S. stercoralis in Togo are rare, and surveys on O. volvulus are important especially under the aspect of MDA of ivermectin which is performed since decades. Methods: Dry blood samples (n = 924) were collected from rural populations in the Régions Central and Plateaux in Togo, and analyzed by parasite-specific real-time PCR and ELISA techniques. Results: Dry blood samples from 733 persons where investigated by real-time PCR tested for DNA of blood-circulating M. perstans microfilaria, and a prevalence of 14.9% was detected. Distinct differences were observed between genders, positivity was higher in men increasing with age, and prevalence was highest in the Région Plateaux in Togo. IgG4 responses to O. volvulus antigen (OvAg) were studied in 924 persons and 59% were found positive. The distribution of parasite infestation between age and gender groups was higher in men increasing with age, and regional differences were detected being highest in the Région Plateaux. The diagnostic approach disclosed 64,5% positive IgG4 responses to S. stercoralis infective third-stage larvae-specific antigen (SsL3Ag) in the surveyed regions. Antigen cross reactivity of SsL3Ag with parasite co-infections may limit the calculated prevalence. Singly IgG4 positive for SsL3Ag were 13.9%, doubly positive for OvAg and SsL3Ag were 35.5% and triply positive for M. perstans, O. volvulus and S. stercoralis were 9.9%. Conclusions: Mansonelliasis, onchocerciasis and strongyloidiasis remain prevalent in the surveyed regions, yet with local differences. Our observations suggest that transmission of M. perstans, O. volvulus and S. stercoralis may be ongoing. The degree of positive test results in the examined rural communities advocate for the continuation of MDA with ivermectin and albendazole, and further investigations should address the intensity of transmission of these parasites. Keywords: Onchocerca volvulus, Mansonella perstans, Strongyloides stercoralis, Onchocerciasis, Mansonelliasis, Strongyloidiasis, Togo, Prevalence
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- 2018
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20. Modelling of flood hazard extent in data sparse areas: a case study of the Oti River basin, West Africa
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Kossi Komi, Jeffrey Neal, Mark A. Trigg, and Bernd Diekkrüger
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Hydrological Modelling ,Flood Inundation Modelling ,LISFLOOD ,LISFLOOD-FP ,Physical geography ,GB3-5030 ,Geology ,QE1-996.5 - Abstract
Study region: Terrain and hydrological data are scarce in many African countries. The coarse spatial resolution of freely available Shuttle Radar Topographic Mission elevation data and the absence of flow gauges on flood-prone reaches, such as the Oti River studied here, make flood inundation modelling challenging in West Africa. Study focus: A flood modelling approach is developed here to simulate flood extent in data scarce regions. The methodology is based on a calibrated, distributed hydrological model for the whole basin to simulate the input discharges for a hydraulic model which is used to predict the flood extent for a 140 km reach of the Oti River. New hydrological insight for the region: Good hydrological model calibration (Nash Sutcliffe coefficient: 0.87) and validation (Nash Sutcliffe coefficient: 0.94) results demonstrate that even with coarse scale (5 km) input data, it is possible to simulate the discharge along this region's rivers, and importantly with a distributed model, derive model flows at any ungauged location within basin. With a lack of surveyed channel bathymetry, modelling the flood was only possible with a parametrized sub-grid hydraulic model. Flood model fit results relative to the observed 2007 flood extent and extensive sensitivity testing shows that this fit (64%) is likely to be as good as is possible for this region, given the coarseness of the terrain digital elevation model.
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- 2017
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21. Onchocerca volvulus infection and serological prevalence, ocular onchocerciasis and parasite transmission in northern and central Togo after decades of Simulium damnosum s.l. vector control and mass drug administration of ivermectin.
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Kossi Komlan, Patrick S Vossberg, Richard G Gantin, Tchalim Solim, Francois Korbmacher, Méba Banla, Koffi Padjoudoum, Potchoziou Karabou, Carsten Köhler, and Peter T Soboslay
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Mass drug administration (MDA) of ivermectin has become the main intervention to control onchocerciasis or "river blindness". In Togo, after many years of MDA, Onchocerca volvulus infection has declined dramatically, and elimination appears achievable, but in certain river basins the current situation remains unknown. We have conducted parasitological, serological, ophthalmological, and entomological assessments in northern and central Togo within the river basins of Ôti, Kéran and Mô.Examinations were completed in 1,455 participants from 11 onchocerciasis sentinel villages, and O. volvulus transmission by Simulium damnosum sensu lato (s.l.) was evaluated. In children (aged 1-10 years), the prevalence of microfilariae (Mf) was 2.3% and in adults it ranged from 5.1 to 13.3%. Positive IgG4 responses to O. volvulus adult (crude) worm antigen (OvAg) and the recombinant Ov16 antigen were in all-ages 48.7% and 34.4%, and 29.1% and 14.9% in children, respectively. In the river basin villages of Kéran, Mô and Ôti, the IgG4 seroprevalences to OvAg in children were 51.7%, 23.5% and 12.7%, respectively, and to the Ov16 antigen 33.3% (Kéran) and 5.2% (Ôti). Onchocerciasis ocular lesions (punctate keratitis, evolving iridocyclitis and chorioretinitis) were observed in children and young adults. O. volvulus-specific DNA (Ov150) was detected by poolscreen in vector samples collected from Tchitchira/Kéran(22.8%), Bouzalo/Mô(11.3%), Baghan/Mô(2.9%) and Pancerys/Ôti(4.9%); prevalences of O. volvulus infection in S. damnosum s.l. were, respectively, 1%, 0.5%, 0.1% and 0.2%.In the northern and central river basins in Togo, interruption of O. volvulus transmission has not yet been attained. Patent O. volvulus infections, positive antibody responses, progressive ocular onchocerciasis were diagnosed, and parasite transmission by S. damnosum s.l. occurred close to the survey locations. Future interventions may require approaches selectively targeted to non-complying endemic populations, to the seasonality of parasite transmission and national onchocerciasis control programs should harmonize cross-border MDA as a coordinated intervention.
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- 2018
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22. Mid-Century Daily Discharge Scenarios Based on Climate and Land Use Change in Ouémé River Basin at Bétérou Outlet
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Lawin Agnidé Emmanuel, Yèkambèssoun N’Tcha M’Po, Chabi Angelbert Biaou, Kossi Komi, Rita Hounguè, Kouassi Benjamin Yao, and Abel Akambi Afouda
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discharge scenarios ,land use scenario ,LISFLOOD ,hydrological modeling ,REMO ,Ouémé basin ,Science - Abstract
This study evaluates the impacts of land use and climate changes on daily discharge in Ouémé river basin at Bétérou outlet. Observed rainfall and temperature over 2002⁻2008 and land use data of 2003 and 2007 were used. Corrected rainfall and temperature data, under RCP4.5 and RCP8.5 scenarios from regional climate model REMO were considered. Two land use scenarios from RIVERTWIN project were used. The first one, Land Use A (LUA), is characterized by stronger economic development, controlled urbanization, implementation of large-scale irrigation schemes, and 3.2% population growth per year. The other one, Land Use B (LUB), is characterized by a weak national economy, uncontrolled settlement, and farmland development as well as 3.5% population growth per year. Four climate and land use combined scenarios (LUA + RCP4.5, LUA + RCP8.5; LUB + RCP4.5, and LUB + RCP8.5) were used for forcing LISFLOOD hydrological model to estimate future discharges at 2050. As a result, during calibration and validation, the LISFLOOD model showed high ability to reproduce historical flows of Ouémé River at Bétérou outlet with Nash⁻Sutcliffe efficiencies greater than 90%. Future discharges simulations show general increase for all land use and climate combined scenarios for all time horizons until 2050. The increase is more exacerbated under the combined scenarios using LUB than the ones using LUA. Increase of river discharge varies between 7.1% and 52% compared to the mean of the reference period 2002⁻2004. These findings highlight growing challenges for water resources managers and planners. Moreover, they emphasize the need to address potential climate and land use changes’ impact on water resources. Then, developing water management plans, strategies to reduce flooding risks must be considered.
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- 2018
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23. Integrated Flood Risk Assessment of Rural Communities in the Oti River Basin, West Africa
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Kossi Komi, Barnabas A. Amisigo, and Bernd Diekkrüger
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community-based disaster risk index ,AHP ,flood hazard ,flood vulnerability ,Science - Abstract
Flood damage in West Africa has increased appreciably during the last two decades. Poor communities are more at risk due to the vulnerability of their livelihoods, especially in rural areas where access to services and infrastructures is limited. The aim of this paper is to identify the main factors that contribute to flood risk of rural communities in the Oti River Basin, Togo. A community-based disaster risk index model is applied. The analyses use primary data collected through questionnaires during fieldwork, the analytic hierarchy process (AHP) method, population and housing census data and flood hazard mapping of the study area. The results showed a moderate level of flood risk despite a high level of hazard and vulnerability for all investigated communities. In addition, the results suggest that decreasing vulnerability through creation of new income-generating opportunities and increasing capacity of communities to manage their own flood risk should be paramount in order to reduce flood risk in the study area. The results of this work contribute to the understanding of flood risk and can be used to identify, assess, and compare flood-prone areas, as well as simulating the impacts of flood management measures in the Oti River Basin.
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- 2016
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24. Regional Flood Frequency Analysis in the Volta River Basin, West Africa
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Kossi Komi, Barnabas A. Amisigo, Bernd Diekkrüger, and Fabien C. C. Hountondji
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flood ,Volta River Basin ,regional frequency analysis ,L-moments ,Science - Abstract
In the Volta River Basin, flooding has been one of the most damaging natural hazards during the last few decades. Therefore, flood frequency estimates are important for disaster risk management. This study aims at improving knowledge of flood frequencies in the Volta River Basin using regional frequency analysis based on L-moments. Hence, three homogeneous groups have been identified based on cluster analysis and a homogeneity test. By using L-moment diagrams and goodness of fit tests, the generalized extreme value and the generalized Pareto distributions are found suitable to yield accurate flood quantiles in the Volta River Basin. Finally, regression models of the mean annual flood with the size of the drainage area, mean basin slope and mean annual rainfall are proposed to enable flood frequency estimation of ungauged sites within the study area.
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- 2016
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25. Modelling the impact of vaccination on COVID-19 in African countries.
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Mathebula D, Amankwah A, Amouzouvi K, Assamagan KA, Azote S, Fajemisin JA, Fankam Fankame JB, Guga A, Kamwela M, Kanduza MM, Mabote TS, Macucule FF, Muronga A, Njeri A, Oluwole MO, and Paulo CM
- Subjects
- Humans, Africa epidemiology, Computational Biology, COVID-19 prevention & control, COVID-19 epidemiology, COVID-19 mortality, COVID-19 Vaccines administration & dosage, Vaccination statistics & numerical data, SARS-CoV-2 immunology
- Abstract
The rapid development of vaccines to combat the spread of COVID-19, caused by the SARS-CoV-2 virus, is a great scientific achievement. Before the development of the COVID-19 vaccines, most studies capitalized on the available data that did not include pharmaceutical measures. Such studies focused on the impact of non-pharmaceutical measures such as social distancing, sanitation, use of face masks, and lockdowns to study the spread of COVID-19. In this study, we used the SIDARTHE-V model, an extension of the SIDARTHE model, which includes vaccination rollouts. We studied the impact of vaccination on the severity of the virus, specifically focusing on death rates, in African countries. The SIRDATHE-V model parameters were extracted by simultaneously fitting the COVID-19 cumulative data of deaths, recoveries, active cases, and full vaccinations reported by the governments of Ghana, Kenya, Mozambique, Nigeria, South Africa, Togo, and Zambia. Using South Africa as a case study, our analysis showed that the cumulative death rates declined drastically with the increased extent of vaccination drives. Whilst the infection rates sometimes increased with the arrival of new coronavirus variants, the death rates did not increase as they did before vaccination., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)
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- 2024
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26. Phosphorus lability across diverse agricultural contexts with legacy sources.
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Simpson ZP, Mott J, Elkin K, Buda A, Faulkner J, Hapeman C, McCarty G, Foroughi M, Hively WD, King K, Osterholz W, Penn C, Williams M, Witthaus L, Locke M, Pawlowski E, Dalzell B, Feyereisen G, Dolph C, Bjorneberg D, Nouwakpo K, Rogers CW, Scott I, Bolster CH, Duriancik L, and Kleinman PJA
- Abstract
The buffering of phosphorus (P) in the landscape delays management outcomes for water quality. If stored in labile form (readily exchangeable and bioavailable), P may readily pollute waters. We studied labile P and its intensity for >600 soils and sediments across seven study locations in the United States. Stocks of labile P were large enough to sustain high P losses for decades, indicating the transport-limited regime typical of legacy P. Sediments were commonly more P-sorptive than nearby soils. Soils in the top 5 cm had 1.3-3.0 times more labile P than soils at 5-15 cm. Stratification in soil test P and total P was, however, less consistent. As P exchange via sorption processes follows the difference in intensities between soil/sediment surface and solution, we built a model for the equilibrium phosphate concentration at net zero sorption (EPC
0 ) as a function of labile P (quantity) and buffer capacity. Despite widely varying properties across sites, the model generalized well for all soils and sediments: EPC0 increased sharply with more labile P and to greater degree when buffer capacity was low or sorption sites were likely more saturated. This quantity-intensity-capacity relationship is central to the P transport models we rely on today. Our data inform the improvement of such P models, which will be necessary to predict the impacts of legacy P. Further, this work reaffirms the position of labile P as a key focus for environmental P management-a view Dr. Sharpley developed in the 1980s with fewer data and resources., (© 2024 The Author(s). Journal of Environmental Quality published by Wiley Periodicals LLC on behalf of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)- Published
- 2024
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27. Can the Kohn-Sham gap be larger than the fundamental gap?
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Kety K and Joubert D
- Abstract
It is often stated that the exact Kohn-Sham HOMO-LUMO gap underestimates the fundamental gap. Here, using the Hubbard dimer as a model Hamiltonian, we show numerically that the exact Kohn-Sham gap can be larger than the fundamental gap.
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- 2024
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28. Performance of ParaHIT® HRP2-Based Rapid Diagnostic Test and Proportions of Plasmodium falciparum Histidine-Rich Protein 2/3 Gene Deletions in Togo.
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Teou DC, Dorkenoo AM, Ataba E, Yakpa K, Sossou E, Ma L, Caspar E, Hemou M, Abdou-Kerim A, and Menard D
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- Humans, Togo epidemiology, Child, Preschool, Infant, Cross-Sectional Studies, Male, Female, Polymerase Chain Reaction methods, Rapid Diagnostic Tests, Protozoan Proteins genetics, Plasmodium falciparum genetics, Malaria, Falciparum diagnosis, Malaria, Falciparum parasitology, Malaria, Falciparum epidemiology, Antigens, Protozoan genetics, Sensitivity and Specificity, Diagnostic Tests, Routine methods, Gene Deletion
- Abstract
In areas where malaria is endemic and microscopes are unavailable, rapid diagnostic tests (RDTs) are essential tools for early diagnosis and prompt and effective treatment. However, HRP2-based RDTs are threatened by the emergence of Plasmodium falciparum parasites that do not carry the pfhrp2 or pfhrp3 gene, leading to false-negative results. Therefore, the aim of this study was to evaluate the performance of the ParaHIT RDT together with the proportion of pfhrp2/3 gene-deleted P. falciparum parasites in Togo. The performance of RDTs compared with microscopy and polymerase chain reaction (PCR) was determined using capillary blood collected by finger prick during a cross-sectional study conducted from September 2021 to January 2022 in children aged 6-59 months at two sentinel sites. Blood spots were collected for molecular analysis. Amplicons from the target regions (exon 2 of hrp2 and hrp3 genes) were generated by multiplex nested PCR and sequenced using Illumina's MiSeq protocol. A total of 278 samples were analyzed for ParaHIT RDT evaluation. The sensitivity and specificity of the RDT test compared with microscopy were 96.4% and 85.7%, respectively, which increased to 97.9% and 90.7%, respectively, when compared with PCR. Of the microscopically and PCR-positive P. falciparum samples, 138 were sequenced to detect pfhrp2/3 deletions. None of the parasites had a single pfhrp2 deletion or a single pfhrp3 deletion. The ParaHIT RDT demonstrated an acceptable level of performance in this evaluation, confirming the use of HRP2-based RDTs for the detection of P. falciparum infection in areas where microscopy is not available in Togo.
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- 2024
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29. Amorphous MoS2 from a machine learning inter-atomic potential.
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Kety K, Namsrai T, Nawaz H, Rostami S, and Seriani N
- Abstract
Amorphous molybdenum disulfide has shown potential as a hydrogen evolution catalyst, but the origin of its high activity is unclear, as is its atomic structure. Here, we have developed a classical inter-atomic potential using the charge equilibration neural network method, and we have employed it to generate atomic models of amorphous MoS2 by melting and quenching processes. The amorphous phase contains an abundance of molybdenum and sulfur atoms in low coordination. Besides the 6-coordinated molybdenum typical of the crystalline phases, a substantial fraction displays coordinations 4 and 5. The amorphous phase is also characterized by the appearance of direct S-S bonds. Density functional theory shows that the amorphous phase is metallic, with a considerable contribution of the 4-coordinated molybdenum to the density of states at the Fermi level. S-S bonds are related to the reduction of sulfur, with the excess electrons spread over several molybdenum atoms. Moreover, S-S bond formation is associated with a distinctive broadening of the 3s states, which could be exploited for experimental characterization of the amorphous phases. The large variety of local environments and the high density of electronic states at the Fermi level may play a positive role in increasing the electrocatalytic activity of this compound., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)
- Published
- 2024
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30. Efficacy of artemether-lumefantrine and dihydroartemisinin-piperaquine and prevalence of molecular markers of anti-malarial drug resistance in children in Togo in 2021.
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Dorkenoo AM, Warsame M, Ataba E, Hemou M, Yakpa K, Sossou E, Mitigmsagou M, Teou CD, Caspar E, Ma L, Djadou KE, Atcha-Oubou T, Rasmussen C, and Menard D
- Subjects
- Child, Adult, Humans, Artemether, Lumefantrine Drug Combination therapeutic use, Artemether, Lumefantrine Drug Combination pharmacology, Prevalence, Togo epidemiology, Prospective Studies, Artemether therapeutic use, Drug Resistance, Tetrahydrofolate Dehydrogenase genetics, Biomarkers, Drug Combinations, Plasmodium falciparum genetics, Antimalarials pharmacology, Antimalarials therapeutic use, Quinolines pharmacology, Quinolines therapeutic use, Malaria, Falciparum drug therapy, Malaria, Falciparum epidemiology, Malaria, Falciparum parasitology, Malaria drug therapy, Piperazines, Artemisinins
- Abstract
Background: Artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the currently recommended first- and second-line therapies for uncomplicated Plasmodium falciparum infections in Togo. This study assessed the efficacy of these combinations, the proportion of Day3-positive patients (D3 +), the proportion of molecular markers associated with P. falciparum resistance to anti-malarial drugs, and the variable performance of HRP2-based malaria rapid diagnostic tests (RDTs)., Methods: A single arm prospective study evaluating the efficacy of AL and DP was conducted at two sites (Kouvé and Anié) from September 2021 to January 2022. Eligible children were enrolled, randomly assigned to treatment at each site and followed up for 42 days after treatment initiation. The primary endpoint was polymerase chain reaction (PCR) adjusted adequate clinical and parasitological response (ACPR). At day 0, samples were analysed for mutations in the Pfkelch13, Pfcrt, Pfmdr-1, dhfr, dhps, and deletions in the hrp2/hrp3 genes., Results: A total of 179 and 178 children were included in the AL and DP groups, respectively. After PCR correction, cure rates of patients treated with AL were 97.5% (91.4-99.7) at day 28 in Kouvé and 98.6% (92.4-100) in Anié, whereas 96.4% (CI 95%: 89.1-98.8) and 97.3% (CI 95%: 89.5-99.3) were observed at day 42 in Kouvé and Anié, respectively. The cure rates of patients treated with DP at day 42 were 98.9% (CI 95%: 92.1-99.8) in Kouvé and 100% in Anié. The proportion of patients with parasites on day 3 (D3 +) was 8.5% in AL and 2.6% in DP groups in Anié and 4.3% in AL and 2.1% DP groups in Kouvé. Of the 357 day 0 samples, 99.2% carried the Pfkelch13 wild-type allele. Two isolates carried nonsynonymous mutations not known to be associated with artemisinin partial resistance (ART-R) (A578S and A557S). Most samples carried the Pfcrt wild-type allele (97.2%). The most common Pfmdr-1 allele was the single mutant 184F (75.6%). Among dhfr/dhps mutations, the quintuple mutant haplotype N51I/C59R/S108N + 437G/540E, which is responsible for SP treatment failure in adults and children, was not detected. Single deletions in hrp2 and hrp3 genes were detected in 1/357 (0.3%) and 1/357 (0.3%), respectively. Dual hrp2/hrp3 deletions, which could affect the performances of HRP2-based RDTs, were not observed., Conclusion: The results of this study confirm that the AL and DP treatments are highly effective. The absence of the validated Pfkelch13 mutants in the study areas suggests the absence of ART -R, although a significant proportion of D3 + cases were found. The absence of dhfr/dhps quintuple or sextuple mutants (quintuple + 581G) supports the continued use of SP for IPTp during pregnancy and in combination with amodiaquine for seasonal malaria chemoprevention., Trial Registration: ACTRN12623000344695., (© 2024. The Author(s).)
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- 2024
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31. Spatial Distribution of Ammonia Concentrations and Modeled Dry Deposition in an Intensive Dairy Production Region.
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Leytem AB, Walker JT, Wu Z, Nouwakpo K, Baublitz C, Bash J, and Beachley G
- Abstract
Agriculture generates ~83% of total US ammonia (NH
3 ) emissions, potentially adversely impacting sensitive ecosystems through wet and dry deposition. Regions with intense livestock production, such as the dairy region of south-central Idaho, generate hotspots of NH3 emissions. Our objective was to measure the spatial and temporal variability of NH3 across this region and estimate its dry deposition. Ambient NH3 was measured using diffusive passive samplers at 8 sites in two transects across the region from 2018-2020. NH3 fluxes were estimated using the Surface Tiled Aerosol and Gaseous Exchange (STAGE) model. Peak NH3 concentrations were 4-5 times greater at a high-density dairy site compared to mixed agriculture/dairy or agricultural sites, and 26 times greater than non-agricultural sites with prominent seasonal trends driven by temperature. Annual estimated dry deposition rates in areas of intensive dairy production can approach 45 kg N ha-1 y-1 , compared to <1 kg N ha-1 y-1 in natural landscapes. Our results suggest that the natural sagebrush steppe landscapes interspersed within and surrounding agricultural areas in southern Idaho receive NH3 dry deposition rates within and above the range of nitrogen critical loads for North American deserts. Finally, our results highlight a need for improved understanding of the role of soil processes in NH3 dry deposition to arid and sparsely vegetated natural ecosystems across the western US., Competing Interests: Conflicts of Interest: The authors declare no conflicts of interest.- Published
- 2023
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32. [ELDERLY UNDERNUTRITION IN HOSPITALS IN LOMÉ: EPIDEMIOLOGICAL, CLINICAL AND BIOLOGICAL ASPECTS].
- Author
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Kodjo K, Apeti S, Djagadou K, and Djibril M
- Published
- 2023
33. [FACTORS ASSOCIATED WITH HIGH CARDIOVASCULAR RISK IN DIABETIC PATIENTS WITH DIABETIC NEPHROPATHY AT THE SYLVANUS UNIVERSITY HOSPITAL IN LOMÉ (TOGO)].
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Kodjo K, Tsevi M, Tchala AB, Djagadou K, and Djibril M
- Published
- 2023
34. Evaluation of the performance of advantage P.f. malaria Card ® and advantage malaria Pan + Pf Card ® , two rapid diagnostic tests for parasitological confirmation of malaria cases in field situation in Togo.
- Author
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Teou DC, Dorkenoo AM, Ataba E, Alidou S, Yakpa K, Abdou-Kerim A, Maman I, and Agbonon A
- Subjects
- Humans, Female, Adolescent, Male, Plasmodium falciparum, Diagnostic Tests, Routine methods, Rapid Diagnostic Tests, Cross-Sectional Studies, Togo epidemiology, Antigens, Protozoan analysis, Sensitivity and Specificity, Malaria, Falciparum diagnosis, Malaria diagnosis
- Abstract
Background: In Togo, malaria remains a major public health problem, and the management of suspected cases requires confirmation with appropriate biological methods. Malaria diagnosis has been improved by the introduction of rapid diagnostic tests (RDTs), recommended by the World Health Organization (WHO) for areas where microscopy is not available. To be used, these RDTs must meet performance criteria defined by the WHO. This study was conducted to evaluate the diagnostic performance of two RDTs: Advantage P.f. Malaria Card
® detecting HRP2 antigen and Advantage Malaria Pan + Pf Card® detecting both HRP2 and pLDH antigens., Methods: This was a cross-sectional analytical study conducted from December 2019 to February 2020 on malaria-suspected cases received in three sentinel sites in Togo and from whom capillary blood was collected to perform the two RDTs according to the manufacturer's instructions. Sensitivity and specificity were estimated by comparing to thick/thin blood smear, the gold standard, and to PCR, which is a more sensitive., Results: A total of 390 participants (54.9% female) with a median age of 18 (± 0.8) years were included in the study. The sensitivity of both Advantage P.f. Malaria Card® and Advantage Malaria Pan + Pf Card® compared to thick/thin blood smear was 91.8% and 91.3%, respectively, and for both the specificity was 94.7%. Compared to PCR, the sensitivity was 84.2% and 83.8%, respectively, and the specificity 96.5%., Conclusions: The performances of the Advantage P.f. Malaria Card® and Advantage Malaria PAN + Pf Card® compared to microscopy, considered the gold standard, were acceptable under the field conditions found in Togo. They can therefore be used for the biological diagnosis of malaria., (© 2023. The Author(s).)- Published
- 2023
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35. Sources of Disparities in Surveillance Mammography Performance and Risk-Guided Recommendations for Supplemental Breast Imaging: A Simulation Study.
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Hubbard RA, Pujol TA, Alhajjar E, Edoh K, and Martin ML
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- Female, Humans, Mammography, Breast, Ethnicity, Neoplasms, Second Primary, Breast Neoplasms diagnostic imaging, Breast Neoplasms epidemiology
- Abstract
Background: Surveillance mammography is recommended for all women with a history of breast cancer. Risk-guided surveillance incorporating advanced imaging modalities based on individual risk of a second cancer could improve cancer detection. However, personalized surveillance may also amplify disparities., Methods: In simulated populations using inputs from the Breast Cancer Surveillance Consortium (BCSC), we investigated race- and ethnicity-based disparities. Disparities were decomposed into those due to primary breast cancer and treatment characteristics, social determinants of health (SDOH) and differential error in second cancer ascertainment by modeling populations with or without variation across race and ethnicity in the distribution of these characteristics. We estimated effects of disparities on mammography performance and supplemental imaging recommendations stratified by race and ethnicity., Results: In simulated cohorts based on 65,446 BCSC surveillance mammograms, when only cancer characteristics varied by race and ethnicity, mammograms for Black women had lower sensitivity compared with the overall population (64.1% vs. 71.1%). Differences between Black women and the overall population were larger when both cancer characteristics and SDOH varied by race and ethnicity (53.8% vs. 71.1%). Basing supplemental imaging recommendations on high predicted second cancer risk resulted in less frequent recommendations for Hispanic (6.7%) and Asian/Pacific Islander women (6.4%) compared with the overall population (10.0%)., Conclusions: Variation in cancer characteristics and SDOH led to disparities in surveillance mammography performance and recommendations for supplemental imaging., Impact: Risk-guided surveillance imaging may exacerbate disparities. Decision-makers should consider implications for equity in cancer outcomes resulting from implementing risk-guided screening programs. See related In the Spotlight, p. 1479., (©2023 American Association for Cancer Research.)
- Published
- 2023
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36. Salvage therapy with brentuximab-vedotin and bendamustine for patients with R/R PTCL: a retrospective study from the LYSA group.
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Aubrais R, Bouabdallah K, Chartier L, Herbaux C, Banos A, Brice P, Sibon D, Schiano JM, Cluzeau T, Laribi K, Le Calloch R, Bellal M, Delapierre B, Daguindau N, Amorim S, Agbetiafa K, Chauchet A, Besson C, Durot E, Bonnet C, Fouillet L, Bijou F, Tournilhac O, Gaulard P, Parrens MC, and Damaj G
- Subjects
- Humans, Brentuximab Vedotin therapeutic use, Bendamustine Hydrochloride therapeutic use, Retrospective Studies, Salvage Therapy, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols adverse effects, Neoplasm Recurrence, Local drug therapy, Chronic Disease, Lymphoma, T-Cell, Peripheral drug therapy, Hodgkin Disease drug therapy
- Abstract
Patients with relapsed or refractory (R/R) peripheral T-cell lymphomas (PTCL) have a poor prognosis. Bendamustine (B) and brentuximab-vedotin (Bv) have shown interesting results in this setting. However, little information is available about their efficacy in combination. This multicenter and retrospective study aimed to evaluate the efficacy and safety of the combination of BBv in patients with noncutaneous R/R PTCL among 21 LYSA centers in France and Belgium. The primary objective was the overall response rate. A total of 82 patients with R/R PTCL were included. The best overall response rate (ORR) was 68%, with 49% of patients in complete response (CR). In multivariable analysis, only the disease status after the last regimen (relapse vs refractory) was associated with the response with an ORR of 83% vs 57%. Median duration of response was 15.4 months for patients in CR. With a median follow-up of 22 months, the median progression free survival (PFS) and overall survival (OS) were 8.3 and 26.3 months respectively. Moreover, patients in CR, who underwent an allogeneic transplant, had a better outcome than patients who did not with a median PFS and OS of 19.3 vs 4.8 months and not reached vs 12.4 months, respectively. Fifty-nine percent of patients experienced grade 3/4 adverse events that were mainly hematologic. BBv is highly active in patients with R/R PTCL and should be considered as a one of the best options of immunochemotherapy salvage combination in this setting and particularly as a bridge to allogeneic transplant for eligible patients., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)
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- 2023
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37. Progress from morbidity control to elimination as a public health problem of schistosomiasis and the status of soil-transmitted helminth infection in Togo: a second impact assessment after ten rounds of mass drug administration.
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Dorkenoo AM, Phillips AE, Klein L, Lack F, Ataba E, Yakpa K, Tagba AE, Assoti BE, Sossou E, Tchalim M, Datagni G, Seim A, Milord MD, and Kassankogno Y
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- Child, Child, Preschool, Animals, Humans, Public Health, Mass Drug Administration, Togo epidemiology, Morbidity, Helminthiasis drug therapy, Helminthiasis epidemiology, Helminthiasis prevention & control, Schistosomiasis drug therapy, Schistosomiasis epidemiology, Schistosomiasis prevention & control
- Abstract
Background: Due to the burden of schistosomiasis (SCH) and soil-transmitted helminths (STH), Togo Ministry of Health launched a program for Preventive Chemotherapy Neglected Tropical Diseases (PC-NTDs) in 2009, initiating integrated mass drug administration (MDA) the following year for the three PC-NTDs: SCH, STH and onchocerciasis. Significant reduction of infection across the country was noted in 2015 during the first impact assessment, following 5 years of high-coverage MDA implemented at the sub-district level for SCH and district level for STH. After another 5 years of effective MDA, a second survey was conducted in 2021 to re-evaluate the situation of SCH and STH., Methods: A cross-section of school-aged children was taken across ten districts of Togo. A total of 302 schools in 92 sub-districts were sampled, with 24 school-aged children per school resulting in 7248 children surveyed. Urine samples were tested by haemastix® for Schistosoma haematobium, with urine filtration for the presence of eggs conducted on haematuria-positive samples. Stool samples were collected in a subset of 34 sub-districts in seven out of the ten surveyed districts, where STH and Schistosoma mansoni endemicity was high during the 2015 impact assessment. Duplicate (two) Kato-Katz analysis was performed for each stool sample. Sociodemographic and school-level water, sanitation and hygiene information was also collected., Results: Overall, SCH prevalence was 5.90% (95% CI: 5.4-6.5), with 5.09% (95% CI: 4.64-5.67) for S. haematobium and 2.56% (95% CI: 1.98-3.29) for S. mansoni. STH prevalence was 19.7% (95% CI: 18.2-21.4), with 19.6% (95% CI: 18.1-21.3) hookworm, 0.08% (95% CI: 2.2-5.8) Trichuris trichiura and 0.04% (95% CI: 0.01-0.33) Ascaris lumbricoides. Compared to baseline, a significant reduction in both SCH (22.2% to 5.90%) and STH (29.2% t0 19.7%) prevalence was observed. Children aged 5-9 years were less infected than older peers aged 10-14 years: 4.76% vs. 7.53% (P < 0.01) for SCH and 17.2% vs. 23.0% (P < 0.01) for STH., Conclusions: After 10 years of high coverage integrated MDA, Togo has achieved low prevalence SCH infection through the sub-district MDA implementation with considerable infection heterogeneity within sub-districts. As STH infection has not reached a level where the infections are not a public health problem, the sub-district treatment strategy could also be adopted in addition to improvement of treatment coverage among preschool age children and hygiene and sanitation practices., (© 2023. BioMed Central Ltd., part of Springer Nature.)
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- 2023
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38. High-Dimensional Contact Network Epidemiology.
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Ackerman A, Martin B, Tanisha M, Edoh K, and Ward JP
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Contact network models are recent alternatives to equation-based models in epidemiology. In this paper, the spread of disease is modeled on contact networks using bond percolation. The weight of the edges in the contact graphs is determined as a function of several variables in which case the weight is the product of the probabilities of independent events involving each of the variables. In the first experiment, the weight of the edges is computed from a single variable involving the number of passengers on flights between two cities within the United States, and in the second experiment, the weight of the edges is computed as a function of several variables using data from 2012 Kenyan household contact networks. In addition, the paper explored the dynamics and adaptive nature of contact networks. The results from the contact network model outperform the equation-based model in estimating the spread of the 1918 Influenza virus.
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- 2023
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39. Description of Antimicrobial Resistance Patterns at the National Institute of Hygiene in Lome, Togo.
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Katawa G, Sadji A, Toudji GA, Touglo K, Tchadié PE, Ritter M, Halatoko W, Tchopba CN, Amessoudji MO, Parcina M, Hoerauf A, Karou DS, and Ameyapoh Y
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- Female, Humans, Drug Resistance, Bacterial, Togo epidemiology, Bacteria, Escherichia coli, Trimethoprim, Sulfamethoxazole Drug Combination, Microbial Sensitivity Tests, Hygiene, Anti-Bacterial Agents pharmacology, Staphylococcus aureus
- Abstract
The monitoring of antimicrobial resistance has become a priority, mainly in developing countries, to control the emergence of multidrug-resistant bacterial strains. This study evaluated the antibiotic resistance profiles of bacteria isolated at the National Institute of Hygiene in Togo. The laboratory records from January 2013 to December 2015 were examined, which showed that a total of 33,147 samples had been analyzed. Among them, vaginal swabs and urine samples were predominant, amounting to 38.17% and 33.24%, respectively. In total, 3,497 Gram-positive and 1,970 Gram-negative bacterial strains were cultured. Enterobacteriaceae (57.6%), Staphylococcus spp. (21.1%), and Streptococcus spp. (10.5%) were primarily isolated. The records showed that over 3 years, Escherichia coli was resistant to piperacillin (79.66%, 75.1%, and 83%), trimethoprim/sulfamethoxazole (79.3%, 82%, and 82.8%), ticarcillin (89%, 89.7%, and 93%), and amoxicillin (94.1%, 94%, and 96.09%), whereas Staphylococcus aureus was resistant to penicillin G. Streptococcaceae isolates were resistant to trimethoprim/sulfamethoxazole (78.11-87.1%), tetracycline (82.2-91.16%), and norfloxacin (86.16-94.3%). Escherichia coli and S. aureus isolated from urine were more resistant to antibiotics than those isolated from vaginal swabs. There is a need to develop new strategies to fight the emergence of multi-resistant bacteria in Togo.
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- 2023
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40. Ionising radiation and cardiovascular disease: systematic review and meta-analysis.
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Little MP, Azizova TV, Richardson DB, Tapio S, Bernier MO, Kreuzer M, Cucinotta FA, Bazyka D, Chumak V, Ivanov VK, Veiga LHS, Livinski A, Abalo K, Zablotska LB, Einstein AJ, and Hamada N
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- Humans, Risk Factors, France, Radiation, Ionizing, Cardiovascular Diseases epidemiology, Cardiovascular Diseases etiology, Myocardial Ischemia epidemiology, Myocardial Ischemia etiology, Coronary Artery Disease complications
- Abstract
Objective: To systematically review and perform a meta-analysis of radiation associated risks of cardiovascular disease in all groups exposed to radiation with individual radiation dose estimates., Design: Systematic review and meta-analysis., Main Outcome Measures: Excess relative risk per unit dose (Gy), estimated by restricted maximum likelihood methods., Data Sources: PubMed and Medline, Embase, Scopus, Web of Science Core collection databases., Eligibility Criteria for Selecting Studies: Databases were searched on 6 October 2022, with no limits on date of publication or language. Animal studies and studies without an abstract were excluded., Results: The meta-analysis yielded 93 relevant studies. Relative risk per Gy increased for all cardiovascular disease (excess relative risk per Gy of 0.11 (95% confidence interval 0.08 to 0.14)) and for the four major subtypes of cardiovascular disease (ischaemic heart disease, other heart disease, cerebrovascular disease, all other cardiovascular disease). However, interstudy heterogeneity was noted (P<0.05 for all endpoints except for other heart disease), possibly resulting from interstudy variation in unmeasured confounders or effect modifiers, which is markedly reduced if attention is restricted to higher quality studies or those at moderate doses (<0.5 Gy) or low dose rates (<5 mGy/h). For ischaemic heart disease and all cardiovascular disease, risks were larger per unit dose for lower dose (inverse dose effect) and for fractionated exposures (inverse dose fractionation effect). Population based excess absolute risks are estimated for a number of national populations (Canada, England and Wales, France, Germany, Japan, USA) and range from 2.33% per Gy (95% confidence interval 1.69% to 2.98%) for England and Wales to 3.66% per Gy (2.65% to 4.68%) for Germany, largely reflecting the underlying rates of cardiovascular disease mortality in these populations. Estimated risk of mortality from cardiovascular disease are generally dominated by cerebrovascular disease (around 0.94-1.26% per Gy), with the next largest contribution from ischaemic heart disease (around 0.30-1.20% per Gy)., Conclusions: Results provide evidence supporting a causal association between radiation exposure and cardiovascular disease at high dose, and to a lesser extent at low dose, with some indications of differences in risk between acute and chronic exposures, which require further investigation. The observed heterogeneity complicates a causal interpretation of these findings, although this heterogeneity is much reduced if only higher quality studies or those at moderate doses or low dose rates are considered. Studies are needed to assess in more detail modifications of radiation effect by lifestyle and medical risk factors., Systematic Review Registration: PROSPERO CRD42020202036., Competing Interests: Competing interest: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: AJE has received speaker fees from Ionetix; has received consulting fees from WL Gore & Associates; has received authorship fees from Wolters Kluwer Healthcare–UpToDate; and has received grants to his institution from Attralus, Canon Medical Systems, Eidos Therapeutics, GE Healthcare, Pfizer, Roche Medical Systems, WL Gore & Associates, and XyloCor Therapeutics; none of these are related to the present work. Otherwise no other authors declare any competing interests., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2023
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41. [Rapid decline of kidney function in diabetic patients in Lomé (Togo)].
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Tsevi YM, Kodjo K, Balaka A, Amede DA, Apeti S, Motte K, Nemi KD, Djagadou KA, Moukaila AR, and Djibril MA
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- Humans, Adolescent, Adult, Young Adult, Middle Aged, Aged, Aged, 80 and over, Cross-Sectional Studies, Glomerular Filtration Rate, Creatinine, Kidney, Risk Factors, Diabetes Mellitus, Type 2 complications, Diabetic Nephropathies complications, Renal Insufficiency, Chronic complications
- Abstract
Objective: To determine the hospital frequency of diabetic patients with a rapid decline in their renal function, to look for the associated factors., Method: Descriptive and analytical cross-sectional study carried out over 12 months (May 1, 2019 to April 31, 2020). Were included all patients aged 18 and over, having achieved at least 3 creatinine during the previous 2 years but spaced at least 6 months apart and having an eGFR calculated from their last creatinine greater than 30 mL/min by the formula of CDK-EPI. We evaluated the eGFR by the CDK-EPI formula using the calculator developed by the Poitiers University Hospital and the Inserm unit of the Francophone Diabetes Society., Results: A total of 80 patients medical files were retained. The rapid decline in renal function was found in 28 patients, either a frequency of 35%. The sex ratio M/F was 1.5. The mean age was 62.93 years (range 18-85 years). Hypertension was the most common comorbidity (92.5%). The very high cardiovascular risk was predominant in 82.5% of cases. The very high renal risk was found in 20 patients, either 25%. Univariate and multivariate analysis showed that the rapid decline in renal function was associated with very high cardiovascular risk (P=0.037) and glomerular filtration rate (P˂0.001)., Conclusion: this study showed a high hospital frequency of the rapid decline in renal function in Togo (35%). Our results have identified the very high cardiovascular risk and glomerular filtration rate as risk factors. The originality of our study was the demonstration of the high proportion of very high cardiovascular risk (82.5%) and very high renal risk (25%) in the evaluation of renal and cardiovascular risk., (Copyright © 2022. Published by Elsevier Masson SAS.)
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- 2022
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42. Integrated climate change and air pollution mitigation assessment for Togo.
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Agbossou A, Fontodji JK, Ayassou K, Tchegueni S, Segla KN, Adjonou K, Bokovi Y, Ajayon AL, Polo-Akpisso A, Kuylenstierna JCI, Malley CS, Michalopoulou E, and Slater J
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- Climate Change, Humans, Particulate Matter analysis, Togo, Air Pollutants analysis, Air Pollution analysis, Air Pollution prevention & control, Environmental Pollutants, Greenhouse Gases
- Abstract
Togo, in west Africa, is vulnerable to the impacts of climate change, but has made a negligible contribution to causing it. Togo ratified the Paris Agreement in 2017, committing to submit Nationally Determined Contributions (NDCs) that outline Togo's climate change mitigation commitment. Togo's capital, Lomé, as well as other areas of Togo have ambient air pollutant levels exceeding World Health Organisation guidelines for human health protection, and 91 % of Togolese households cook using solid biomass, elevating household air pollution exposure. In Togo's updated NDC, submitted in 2021, Togo acknowledges the importance and opportunity of achieving international climate change mitigation targets in ways that improve air quality and achieve health benefits for Togo's citizens. The aim of this work is to evaluate priority mitigation measures in an integrated assessment of air pollutant, Short-Lived Climate Pollutant (SLCP) and Greenhouse Gas (GHG) emissions to identify their effectiveness in simultaneously reducing air pollution and Togo's contribution to climate change. The mitigation assessment quantifies emissions for Togo and Grand Lomé from all major source sectors for historical years between 2010 and 2018, for a baseline projection to 2030 and for mitigation scenarios evaluating ten mitigation measures. The assessment estimates that Togo emitted ~21 million tonnes of GHG emissions in 2018, predominantly from the energy and Agriculture, Forestry and Other Land Use sectors. GHG emissions are projected to increase 42 % to 30 million tonnes in 2030 without implementation of mitigation policies and measures. The implementation of the ten identified priority mitigation measures could reduce GHG emissions by ~20 % in 2030 compared to the baseline, while SLCPs and air pollutants were estimated to be reduced more, with a more than 75 % reduction in black carbon emissions in 2030. This work therefore provides a clear pathway by which Togo can reduce its already small contribution to climate change while simultaneously achieving local benefits for air quality and human health in Togo and Grand Lomé., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2022
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43. Floristic composition and turnover analysis in Dahomey Gap and the surrounding sub-humid Togolese mountain minor forest refuges: Importance for biogeography and biodiversity conservation in sub-Saharan Africa.
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Adjossou K, Kokou K, and Deconchat M
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The origin of Dahomey Gap (DG) flora is one of the central biogeographical questions in sub-Saharan, which has been addressed in several studies. However, floristic evidence based on representative samples from the DG seems to be lacking in the scientific debate. The present study was conducted to fill this gap. Specifically, we assessed Togolese mountain riparian forests as minor forest refugia, examined their contribution to larger sub-Saharan forest refugia, and discussed the significance of these findings for biogeography and biodiversity conservation. Southwest Togo, West Africa, and sub-Saharan Upper Guinea Region Floristic data were collected in riparian forests through an intensive botanical inventory ( n = 198; 50 × 10 m
2 ). A comparative analysis was performed based on the floristic evidence related to forest refuges. The results showed significantly high species richness (868 species) and a high gamma and beta diversity associated with spatial turnover patterns. They also showed a high affinity between the study forests and large sub-Saharan forest refugia. Riparian forests share about 60% of their current species richness with large sub-Saharan forest refugia and contained refuge bio-indicator species. The floristic evidence, consistent with those of other studies, suggests that Togolese mountains would have very ancient origins and have experienced paleoclimatic events. The studied riparian would have served as refuges during recurrent climatic episodes. Our results support the minimal forest fragmentation hypothesis (network of refugia along rivers). However, they seem to be incompatible with the idea that the DG flora may be essentially a relic of the early Holocene. In sub-Saharan Africa, where maintaining a vast area of natural forest is difficult due to human pressure, efforts to preserve maximum species diversity should include a focus on the conservation of minor forest refuges, particularly in sub-humid mountain riparian zone., Competing Interests: The authors declare no conflicts of interest., (© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)- Published
- 2022
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44. Cancer risks among studies of medical diagnostic radiation exposure in early life without quantitative estimates of dose.
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Little MP, Wakeford R, Bouffler SD, Abalo K, Hauptmann M, Hamada N, and Kendall GM
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- Humans, Radiation Dosage, Radiation, Ionizing, Risk, Leukemia, Neoplasms epidemiology, Neoplasms, Radiation-Induced epidemiology, Radiation Exposure adverse effects
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Background: There is accumulating evidence of excess risk of cancer in various populations exposed at acute doses below several tens of mSv or doses received over a protracted period. There is also evidence that relative risks are generally higher after radiation exposures in utero or in childhood., Methods and Findings: We reviewed and summarised evidence from 89 studies of cancer following medical diagnostic exposure in utero or in childhood, in which no direct estimates of radiation dose are available. In all of the populations studied exposure was to sparsely ionizing radiation (X-rays). Several of the early studies of in utero exposure exhibit modest but statistically significant excess risks of several types of childhood cancer. There is a highly significant (p < 0.0005) negative trend of odds ratio with calendar period of study, so that more recent studies tend to exhibit reduced excess risk. There is no significant inter-study heterogeneity (p > 0.3). In relation to postnatal exposure there are significant excess risks of leukaemia, brain and solid cancers, with indications of variations in risk by cancer type (p = 0.07) and type of exposure (p = 0.02), with fluoroscopy and computed tomography scans associated with the highest excess risk. However, there is highly significant inter-study heterogeneity (p < 0.01) for all cancer endpoints and all but one type of exposure, although no significant risk trend with calendar period of study., Conclusions: Overall, this large body of data relating to medical diagnostic radiation exposure in utero provides support for an associated excess risk of childhood cancer. However, the pronounced heterogeneity in studies of postnatal diagnostic exposure, the implied uncertainty as to the meaning of summary measures, and the distinct possibilities of bias, substantially reduce the strength of the evidence from the associations we observe between radiation imaging in childhood and the subsequent risk of cancer being causally related to radiation exposure., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Richard Wakeford receives a consultancy fee as a member of the Technical Working Party of the Compensation Scheme for Radiation-linked Diseases (http://www.csrld.org.uk). No other authors report conflicts of interest., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)
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- 2022
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45. Intensive chemotherapy followed by autologous stem cell transplantation in primary central nervous system lymphomas (PCNSLs). Therapeutic outcomes in real life-experience of the French Network.
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Schenone L, Houillier C, Tanguy ML, Choquet S, Agbetiafa K, Ghesquières H, Damaj G, Schmitt A, Bouabdallah K, Ahle G, Gressin R, Cornillon J, Houot R, Marolleau JP, Fornecker LM, Chinot O, Peyrade F, Bouabdallah R, Moluçon-Chabrot C, Gyan E, Chauchet A, Casasnovas O, Oberic L, Delwail V, Abraham J, Roland V, Waultier-Rascalou A, Willems L, Morschhauser F, Fabbro M, Ursu R, Thieblemont C, Jardin F, Tempescul A, Malaise D, Touitou V, Nichelli L, Le Garff-Tavernier M, Plessier A, Bourget P, Bonmati C, Wantz-Mézières S, Giordan Q, Dorvaux V, Charron C, Jabeur W, Hoang-Xuan K, Taillandier L, and Soussain C
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- Antineoplastic Combined Chemotherapy Protocols therapeutic use, Busulfan, Carmustine therapeutic use, Central Nervous System pathology, Cyclophosphamide therapeutic use, Etoposide, Humans, Neoplasm Recurrence, Local drug therapy, Prospective Studies, Thiotepa, Transplantation, Autologous, Treatment Outcome, Central Nervous System Neoplasms drug therapy, Central Nervous System Neoplasms pathology, Hematopoietic Stem Cell Transplantation adverse effects, Lymphoma drug therapy
- Abstract
We analysed the therapeutic outcomes of all consecutive patients with primary central nervous system lymphoma (PCNSL) registered in the prospective French database for PCNSL and treated with intensive chemotherapy (IC) followed by autologous stem cell transplantation (IC-ASCT) between 2011 and November 2019 (271 patients recruited, 266 analysed). In addition, treatment-related complications of thiotepa-based IC-ASCT were analysed from the source files of 85 patients from 3 centers. Patients had received IC-ASCT either in first-line treatment (n = 147) or at relapse (n = 119). The median age at IC-ASCT was 57 years (range: 22-74). IC consisted of thiotepa-BCNU (n = 64), thiotepa-busulfan (n = 24), BCNU-etoposide-cytarabine-melphalan (BEAM, n = 36) and thiotepa-busulfan-cyclophosphamide (n = 142). In multivariate analysis, BEAM and ASCT beyond the first relapse were adverse prognostic factors for relapse risk. The risk of treatment-related mortality was higher for ASCT performed beyond the first relapse and seemed higher for thiotepa-busulfan-cyclophosphamide. Thiotepa-BCNU tends to result in a higher relapse rate than thiotepa-busulfan-cyclophosphamide and thiotepa-busulfan. This study confirms the role of IC-ASCT in first-line treatment and at first-relapse PCNSL (5-year overall survival rates of 80 and 50%, respectively). The benefit/risk ratio of thiotepa-busulfan/thiotepa-busulfan-cyclophosphamide-ASCT could be improved by considering ASCT earlier in the course of the disease and dose adjustment of the IC., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
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- 2022
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46. Onchocerca volvulus-specific antibody and cellular responses in onchocerciasis patients treated annually with ivermectin for 30 years and exposed to parasite transmission in central Togo.
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Johanns SI, Gantin RG, Wangala B, Komlan K, Halatoko WA, Banla M, Karabou P, Luty AJ, Schulz-Key H, Köhler C, and Soboslay PT
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- Aged, Animals, Cytokines, Humans, Immunoglobulin G, Interleukin-10, Ivermectin therapeutic use, Microfilariae, Mitogens therapeutic use, Onchocerca, Togo epidemiology, Intestinal Volvulus, Onchocerca volvulus, Onchocerciasis, Parasites, Simuliidae parasitology
- Abstract
Background: Annual mass drug administrations (MDA) of ivermectin will strongly reduce Onchocerca volvulus microfilariae (mf) in the skin and in the onchocerciasis patients' eyes. Ivermectin treatment will also affect the expression of immunity in patients, such that activated immune defenses may help control and contribute to clearance of mf of O. volvulus. Longitudinal surveys are a prerequisite to determining the impact of ivermectin on the status of anti-parasite immunity, notably in risk zones where parasite transmission and active O. volvulus infections persist., Methodology/principal Findings: Onchocerciasis patients were treated annually with ivermectin and their Onchocerca volvulus antigen (OvAg) specific IgG and cellular responses were investigated before and at 30 years post initial ivermectin treatment (30yPT). Repeated annual ivermectin treatments eliminated persisting O. volvulus microfilariae (mf) from the skin of patients and abrogated patent infections. The OvAg-specific IgG1 and IgG4 responses were diminished at 30yPT to the levels observed in endemic controls. Prior to starting ivermectin treatment, OvAg-induced cellular productions of IL-10, IFN-γ, CCL13, CCL17 and CCL18 were low in patients, and at 30yPT, cellular cytokine and chemokine responses increased to the levels observed in endemic controls. In contrast, mitogen(PHA)- induced IL-10, IFN-γ, CCL17 and CCL18 cellular production was diminished. This divergent response profile thus revealed increased parasite antigen-specific but reduced polyclonal cellular responsiveness in patients. The transmission of O. volvulus continued at the patients' location in the Mô river basin in central Togo 2018 and 2019 when 0.58% and 0.45%, respectively, of Simulium damnosum s.l. vector blackflies carried O. volvulus infections., Conclusions/significance: Repeated annual ivermectin treatment of onchocerciasis patients durably inhibited their patent O. volvulus infections despite ongoing low-level parasite transmission in the study area. Repeated MDA with ivermectin affects the expression of immunity in patients. O. volvulus parasite-specific antibody levels diminished to levels seen in infection-free endemic controls. With low antibody levels, antibody-dependent cellular cytotoxic responses against tissue-dwelling O. volvulus larvae will weaken. O. volvulus antigen inducible cytokine and chemokine production increased in treated mf-negative patients, while their innate responsiveness to mitogen declined. Such lower innate responsiveness in elderly patients could contribute to reduced adaptive immune responses to parasite infections and vaccines. On the other hand, increased specific cellular chemokine responses in mf-negative onchocerciasis patients could reflect effector cell activation against tissue invasive larval stages of O. volvulus. The annual Simulium damnosum s.l. biting rate observed in the Mô river basin was similar to levels prior to initiation of MDA with ivermectin, and the positive rtPCR results reported here confirm ongoing O. volvulus transmission., Competing Interests: The authors have declared that no competing interests exist.
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- 2022
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47. Neisseria meningitidis Serogroup C Clonal Complex 10217 Outbreak in West Kpendjal Prefecture, Togo 2019.
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Feagins AR, Sadji AY, Topaz N, Itsko M, Halatoko JWA, Dzoka A, Labite J, Kata Y, Gomez S, Kossi K, Assane H, Nikiema-Pessinaba C, Novak R, Marjuki H, and Wang X
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- Disease Outbreaks, Female, Humans, Male, Serogroup, Togo epidemiology, Meningitis, Bacterial microbiology, Meningitis, Meningococcal epidemiology, Meningitis, Meningococcal microbiology, Meningitis, Meningococcal prevention & control, Neisseria meningitidis genetics
- Abstract
Togo has reported seasonal meningitis outbreaks caused by non-Neisseria meningitidis serogroup A (NmA) pathogens since the introduction of meningococcal serogroup A conjugate vaccine (MACV, MenAfriVac) in 2014. From 2016 to 2017, NmW caused several outbreaks. In early 2019, a NmC outbreak was detected in the Savanes region of Togo and its investigation is described here. Under case-based surveillance, epidemiological and clinical data, and cerebrospinal fluid specimens were collected for every suspected case of meningitis. Specimens were tested for meningitis pathogens using confirmatory microbiological and molecular methods. During epidemic weeks 9 to 15, 199 cases were reported, with 179 specimens being available for testing and 174 specimens (97.2%) were tested by at least one confirmatory method. The NmC was the predominant pathogen confirmed (93.9%), belonging to sequence type (ST)-9367 of clonal complex (CC) 10217. All NmC cases were localized to the West Kpendjal district of the Savanes region with attack rates ranging from 4.1 to 18.8 per 100,000 population and case fatality rates ranging up to 2.2% during weeks 9 to 15. Of the 93 NmC confirmed cases, 63.4% were males and 88.2% were in the 5 to 29 age group. This is the first report of a NmC meningitis outbreak in Togo. The changing epidemiology of bacterial meningitis in the meningitis belt post-MACV highlights the importance of monitoring of emerging strain and country preparedness for outbreaks in the region. IMPORTANCE The recent emergence of an invasive NmC strain in Togo is an example of the changing bacterial meningitis epidemiology in the meningitis belt post-MACV. The current epidemiology includes the regional circulation of various non-NmA serogroups, which emphasizes the need for effective molecular surveillance, laboratory diagnosis, and a multivalent vaccine that is effective against all serogroups in circulation.
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- 2022
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48. Timing of high-dose methotrexate CNS prophylaxis in DLBCL: a multicenter international analysis of 1384 patients.
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Wilson MR, Eyre TA, Kirkwood AA, Wong Doo N, Soussain C, Choquet S, Martinez-Calle N, Preston G, Ahearne M, Schorb E, Moles-Moreau MP, Ku M, Rusconi C, Khwaja J, Narkhede M, Lewis KL, Calimeri T, Durot E, Renaud L, Øvlisen AK, McIlroy G, Ebsworth TJ, Elliot J, Santarsieri A, Ricard L, Shah N, Liu Q, Zayac AS, Vassallo F, Lebras L, Roulin L, Lombion N, Manos K, Fernandez R, Hamad N, Lopez-Garcia A, O'Mahony D, Gounder P, Forgeard N, Lees C, Agbetiafa K, Strüßmann T, Htut TW, Clavert A, Scott H, Guidetti A, Barlow BR, Tchernonog E, Smith J, Miall F, Fox CP, Cheah CY, El Galaly TC, Ferreri AJM, Cwynarski K, and McKay P
- Subjects
- Aged, Antineoplastic Combined Chemotherapy Protocols adverse effects, Cyclophosphamide, Doxorubicin, Humans, Methotrexate, Neoplasm Recurrence, Local drug therapy, Prednisone, Retrospective Studies, Rituximab therapeutic use, Vincristine, Central Nervous System Neoplasms drug therapy, Central Nervous System Neoplasms pathology, Central Nervous System Neoplasms prevention & control, Lymphoma, Large B-Cell, Diffuse pathology
- Abstract
Prophylactic high-dose methotrexate (HD-MTX) is often used for diffuse large B-cell lymphoma (DLBCL) patients at high risk of central nervous system (CNS) relapse, despite limited evidence demonstrating efficacy or the optimal delivery method. We conducted a retrospective, international analysis of 1384 patients receiving HD-MTX CNS prophylaxis either intercalated (i-HD-MTX) (n = 749) or at the end (n = 635) of R-CHOP/R-CHOP-like therapy (EOT). There were 78 CNS relapses (3-year rate 5.7%), with no difference between i-HD-MTX and EOT: 5.7% vs 5.8%, P = .98; 3-year difference: 0.04% (-2.0% to 3.1%). Conclusions were unchanged on adjusting for baseline prognostic factors or on 6-month landmark analysis (n = 1253). In patients with a high CNS international prognostic index (n = 600), the 3-year CNS relapse rate was 9.1%, with no difference between i-HD-MTX and EOT. On multivariable analysis, increasing age and renal/adrenal involvement were the only independent risk factors for CNS relapse. Concurrent intrathecal prophylaxis was not associated with a reduction in CNS relapse. R-CHOP delays of ≥7 days were significantly increased with i-HD-MTX vs EOT, with 308 of 1573 (19.6%) i-HD-MTX treatments resulting in a delay to subsequent R-CHOP (median 8 days). Increased risk of delay occurred in older patients when delivery was later than day 10 in the R-CHOP cycle. In summary, we found no evidence that EOT delivery increases CNS relapse risk vs i-HD-MTX. Findings in high-risk subgroups were unchanged. Rates of CNS relapse in this HD-MTX-treated cohort were similar to comparable cohorts receiving infrequent CNS prophylaxis. If HD-MTX is still considered for certain high-risk patients, delivery could be deferred until R-CHOP completion., (© 2022 by The American Society of Hematology.)
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- 2022
- Full Text
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49. Potential Emergence of Plasmodium Resistance to Artemisinin Induced by the Use of Artemisia annua for Malaria and COVID-19 Prevention in Sub-African Region.
- Author
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Ataba E, Dorkenoo AM, Nguepou CT, Bakai T, Tchadjobo T, Kadzahlo KD, Yakpa K, and Atcha-Oubou T
- Subjects
- Humans, Plasmodium falciparum, Antimalarials pharmacology, Antimalarials therapeutic use, Artemisia annua, Artemisinins pharmacology, Artemisinins therapeutic use, COVID-19 prevention & control, Malaria drug therapy, Malaria epidemiology, Malaria prevention & control, Malaria, Falciparum drug therapy, Plasmodium
- Abstract
Plasmodium resistance to antimalarial drugs is an obstacle to the elimination of malaria in endemic areas. This situation is particularly dramatic for Africa, which accounts for nearly 92% of malaria cases worldwide. Drug pressure has been identified as a key factor in the emergence of antimalarial drug resistance. Indeed, this pressure is favoured by several factors, including the use of counterfeit forms of antimalarials, inadequate prescription controls, poor adherence to treatment regimens, dosing errors, and the increasing use of other forms of unapproved antimalarials. This resistance has led to the replacement of chloroquine (CQ) by artemisinin-based combination therapies (ACTs) which are likely to become ineffective in the coming years due to the uncontrolled use of Artemisia annua in the sub-Saharan African region for malaria prevention and COVID-19. The use of Artemisia annua for the prevention of malaria and COVID-19 could be an important factor in the emergence of resistance to Artemisinin-based combination therapies., (© 2021. The Author(s), under exclusive licence to The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)
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- 2022
- Full Text
- View/download PDF
50. Review of the risk of cancer following low and moderate doses of sparsely ionising radiation received in early life in groups with individually estimated doses.
- Author
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Little MP, Wakeford R, Bouffler SD, Abalo K, Hauptmann M, Hamada N, and Kendall GM
- Subjects
- Humans, Radiation Dosage, Radiation, Ionizing, Risk, Brain Neoplasms, Leukemia, Neoplasms, Radiation-Induced epidemiology, Neoplasms, Radiation-Induced etiology
- Abstract
Background: The detrimental health effects associated with the receipt of moderate (0.1-1 Gy) and high (>1 Gy) acute doses of sparsely ionising radiation are well established from human epidemiological studies. There is accumulating direct evidence of excess risk of cancer in a number of populations exposed at lower acute doses or doses received over a protracted period. There is evidence that relative risks are generally higher after radiation exposures in utero or in childhood., Methods and Findings: We reviewed and summarised evidence from 60 studies of cancer or benign neoplasms following low- or moderate-level exposure in utero or in childhood from medical and environmental sources. In most of the populations studied the exposure was predominantly to sparsely ionising radiation, such as X-rays and gamma-rays. There were significant (p < 0.001) excess risks for all cancers, and particularly large excess relative risks were observed for brain/CNS tumours, thyroid cancer (including nodules) and leukaemia., Conclusions: Overall, the totality of this large body of data relating to in utero and childhood exposure provides support for the existence of excess cancer and benign neoplasm risk associated with radiation doses < 0.1 Gy, and for certain groups exposed to natural background radiation, to fallout and medical X-rays in utero, at about 0.02 Gy., (Published by Elsevier Ltd.)
- Published
- 2022
- Full Text
- View/download PDF
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