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Background: Malaria remains a threat in sub-Saharan Africa, particularly in Côte d'Ivoire, where it is endemic and represents the leading cause of hospital consultations, morbidity and mortality. The strong climatic variations that exist between coastal and savannah areas of Côte d'Ivoire suggest that vector control interventions should be scheduled according to the eco-epidemiological diversity. This study evaluates bioecological parameters of vectors and malaria transmission in two health districts, one coastal and one central of Côte d'Ivoire., Methods: The study was conducted in the coastal (Jacqueville) and savannah (Béoumi) areas of Côte d'Ivoire from November 2018 to March 2019. Human Landing Catches (HLC) were conducted monthly at the study sites to determine Anopheles vector species composition, biting behaviour as well as entomological parameters of malaria transmission. Mosquitoes were collected over 12 h, from 6:00 pm to 6:00 am during 2 days per month. Mosquitoes infectivity was revealed by enzyme-linked immunosorbent assay (ELISA) for Plasmodium falciparum circumsporozoite protein. A random sample of 100 Anopheles gambiae sensu lato (s.l.) including all CSP-positive females, were further classified by polymerase chain reaction (PCR) at the species and molecular form levels., Results: In Jacqueville, 853 (99.7%) An. gambiae s.l., and 3 (0.35%) Anopheles pharoensis were collected. In Béoumi, 811 (96.3%) An. gambiae s.l., 23 (2.73%) Anopheles funestus and 8 (0. 95%) An. pharoensis have been found. Anopheles coluzzii represented the only species of the An. gambiae complex in Jacqueville. Among the An. gambiae s.l. samples tested in Beoumi, 29 (58%) were An. coluzzii and the rest 21 (42%) was An. gambiae sensu stricto. The human biting rate (HBR) in Jacqueville increased from 5.7 (b/p/n) in November to 17.3 (b/p/n) in March. Conversely in Béoumi the HBR decreased from 16.4 (b/p/n) in November to 0.69 (b/p/n) in March. In Jacqueville, the entomological inoculation rate (EIR) varies from 0.21 to 0.56 (ib/p/n) with the pic of 0.56 (ib/p/n) in February. In Béoumi no infection was detected in the parous An. gambiae s.l. samples tested during the study period., Conclusions: This study evaluates bioecological parameters of vectors and malaria transmission in two health districts, one coastal and one central of Côte d'Ivoire., Competing Interests: Declarations. The findings and conclusions expressed herein are those of the author(s) and do not necessarily represent the official position of neither USAID nor PMI, nor those of Centers for Disease Control and Prevention (CDC). Ethics approval and consent to participate: The study protocol has been approved by the Côte d'Ivoire national ethics committee prior to the start of the experiments. The study protocol has been approved by the local health and administrative authorities. Before starting the study, the village chiefs gave their oral informed consent. In addition, all entomological surveys and sample collections carried out on private land or private residential areas were carried out with the authorization and informed written consent of the residents. Volunteers participating in the HLC have given written informed consent for their participation. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: The city of Abidjan, Côte d'Ivoire has increasingly faced multiple outbreaks of Aedes mosquito-borne arboviral diseases (e.g., dengue (DEN) and yellow fever (YF)) during the recent years, 2017-2024. Thus, we assessed and compared Aedes aegypti larval and adult population dynamics and Stegomyia indices in four urbanized areas with differential arboviral incidences in Abidjan, Côte d'Ivoire., Methods: From August 2019 to July 2020, we sampled Aedes mosquito immatures (larvae and pupae), adults and breeding habitats in Anono and Gbagba with high arboviral incidences and Ayakro and Entente with low arboviral incidences in the Abidjan city, using standardized methods. Sampling was conducted in the peridomestic and domestic (indoors and outdoors) premises during short dry season (SDS), short rainy season (SRS), long dry season (LDS) and long rainy season (LRS). The abdomens and ovaries of Ae. aegypti females were examined to determine their blood-meal and parity statuses. Stegomyia indices (container index: CI, house index: HI and Breteau index: BI), blood-meal status and parity rates were compared by study sites and seasons and with the World Health Organization (WHO)-established epidemic thresholds., Results: Overall, Aedes and arboviral risk indices were high and similar between the four study areas. In total, 86,796 mosquitoes were identified and dominated by Ae. aegypti species (97.14%, 84,317/86,796). The most productive larval breeding habitats were tires, discarded containers and water storage containers. CI, HI, and BI in Anono (22.4%, 33.5% and 89.5), Ayakro (23.1%, 43.8% and 91.0), Entente (15.9%, 24.8% and 48.5) and Gbagba (23.3%, 43.0% and 102.0) were high in the respective study sites. Stegomyia indices were higher than the WHO-established epidemic thresholds during any seasons for DEN, and LRS and SRS for YF. The numbers of Ae. aegypti-positive breeding sites were higher in the domestic premises (68.0%, 900/1,324) than in the peridomestic premises (32.0%, 424/1,324). In the domestic premises, Ae. aegypti-positive breeding sites (94.6%, 851/4,360) and adult individuals (93.4%, 856/916) were mostly found outdoors of houses. Aedes aegypti adult females were mostly unfed (51.3%, 203/396), followed by blood-fed (22.2%, 88/396), gravid (13.9%, 55/396) and half-gravid (12.6%, 50/396), and had parity rate of 49.7% (197/396) that was comparable between the study sites., Conclusions: The city of Abidjan, Côte d'Ivoire is highly infested with Ae. aegypti which showed comparable ecological patterns across study sites and seasons. Thus, the local communities are exposed to high and permanent risks of transmission of DEN and YF viruses that were above the WHO-established epidemic thresholds throughout. The results provide a baseline for future vector studies needed to further characterize the observed patterns of local Ae. aegypti abundances and behaviors, and risks of transmission of these arboviruses. Community-based larval source management of identified productive containers might reduce Ae. aegypti numbers and risks of transmission of Aedes-borne arboviruses in Abidjan, and other sub-Saharan African cities., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Adjobi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: The recent reduction in malaria burden in Côte d'Ivoire is largely attributable to the use of long-lasting insecticidal nets (LLINs). However, this progress is threatened by insecticide resistance and behavioral changes in Anopheles gambiae sensu lato (s.l.) populations and residual malaria transmission, and complementary tools are required. Thus, this study aimed to assess the efficacy of the combined use of LLINs and Bacillus thuringiensis israelensis (Bti), in comparison with LLINs., Methods: This study was conducted in the health district of Korhogo, northern Côte d'Ivoire, within two study arms (LLIN + Bti arm and LLIN-only arm) from March 2019 to February 2020. In the LLIN + Bti arm, Anopheles larval habitats were treated every fortnight with Bti in addition to the use of LLINs. Mosquito larvae and adults were sampled and identified morphologically to genus and species using standard methods. The members of the An. gambiae complex were determined using a polymerase chain reaction technique. Plasmodium infection in An. gambiae s.l. and malaria incidence in local people was also assessed., Results: Overall, Anopheles spp. larval density was lower in the LLIN + Bti arm 0.61 [95% CI 0.41-0.81] larva/dip (l/dip) compared with the LLIN-only arm 3.97 [95% CI 3.56-4.38] l/dip (RR = 6.50; 95% CI 5.81-7.29; P < 0.001). The overall biting rate of An. gambiae s.l. was 0.59 [95% CI 0.43-0.75] biting/person/night in the LLIN + Bti arm against 2.97 [95% CI 2.02-3.93] biting/person/night in LLIN-only arm (P < 0.001). Anopheles gambiae s.l. was predominantly identified as An. gambiae sensu stricto (s.s.) (95.1%, n = 293), followed by Anopheles coluzzii (4.9%; n = 15). The human-blood index was 80.5% (n = 389) in study area. EIR was 1.36 infected bites/person/year (ib/p/y) in the LLIN + Bti arm against 47.71 ib/p/y in the LLIN-only arm. Malaria incidence dramatically declined from 291.8‰ (n = 765) to 111.4‰ (n = 292) in LLIN + Bti arm (P < 0.001)., Conclusions: The combined use of LLINs with Bti significantly reduced the incidence of malaria. The LLINs and Bti duo could be a promising integrated approach for effective vector control of An. gambiae for elimination of malaria., (© 2024. The Author(s).)

Background: Anopheles mosquito resistance to insecticide remains a serious threat to malaria vector control affecting several sub-Sahara African countries, including Côte d'Ivoire, where high pyrethroid, carbamate and organophosphate resistance have been reported. Since 2017, new insecticides, namely neonicotinoids (e.g.; clothianidin) and pyrroles (e.g.; chlorfenapyr) have been pre-qualified by the World Health Organization (WHO) for use in public health to manage insecticide resistance for disease vector control., Methods: Clothianidin and chlorfenapyr were tested against the field-collected Anopheles gambiae populations from Gagnoa, Daloa and Abengourou using the WHO standard insecticide susceptibility biossays. Anopheles gambiae larvae were collected from several larval habitats, pooled and reared to adulthood in each site in July 2020. Non-blood-fed adult female mosquitoes aged 2 to 5 days were exposed to diagnostic concentration deltamethrin, permethrin, alpha-cypermethrin, bendiocarb, and pirimiphos-methyl. Clothianidin 2% treated papers were locally made and tested using WHO tube bioassay while chlorfenapyr (100 µg/bottle) was evaluated using WHO bottle assays. Furthermore, subsamples of exposed mosquitoes were identified to species and genotyped for insecticide resistance markers including the knock-down resistance (kdr) west and east, and acetylcholinesterase (Ace-1) using molecular techniques., Results: High pyrethroid resistance was recorded with diagnostic dose in Abengourou (1.1 to 3.4% mortality), in Daloa (15.5 to 33.8%) and in Gagnoa (10.3 to 41.6%). With bendiocarb, mortality rates ranged from 49.5 to 62.3%. Complete mortality (100% mortality) was recorded with clothianidin in Gagnoa, 94.9% in Daloa and 96.6% in Abengourou, while susceptibility (mortality > 98%) to chlorfenapyr 100 µg/bottle was recorded at all sites and to pirimiphos-methyl in Gagnoa and Abengourou. Kdr-west mutation was present at high frequency (0.58 to 0.73) in the three sites and Kdr-east mutation frequency was recorded at a very low frequency of 0.02 in both Abengourou and Daloa samples and absent in Gagnoa. The Ace-1 mutation was present at frequencies between 0.19 and 0.29 in these areas. Anopheles coluzzii represented 100% of mosquitoes collected in Daloa and Gagnoa, and 72% in Abengourou., Conclusions: This study showed that clothianidin and chlorfenapyr insecticides induce high mortality in the natural and pyrethroid-resistant An. gambiae populations in Côte d'Ivoire. These results could support a resistance management plan by proposing an insecticide rotation strategy for vector control interventions., (© 2024. The Author(s).)

Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with Anopheles ( n = 100 species), Culex ( n = 56 species), and Aedes ( n = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, Orthopodomyia , Lutzia , and Verrallina , but individuals of the genera Toxorhinchites and Finlayas were not identified at the species level. We found that two Aedes species ( Ae. aegypti and Ae. albopictus ) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.

Background: Space spraying of insecticides is still an important means of controlling Aedes and Culex mosquitoes and arboviral diseases. This study evaluated the space spray efficacy of Fludora Co-Max EW, (water-based insecticide space spray combining flupyradifurone and transfluthrin with film forming aqueous spray technology (FFAST)), against wild insecticide-resistant Aedes aegypti and Culex quinquefasciatus mosquitoes from Abidjan, Côte d'Ivoire, compared with K-Othrine EC (deltamethrin-only product), in small-scale field trials., Methods: Wild Ae. aegypti and Cx. quinquefasciatus mosquito larvae were collected in Abidjan, Côte d'Ivoire from August to December 2020. Mosquito larvae were reared in the laboratory until the adult stage. Fludora Co-Max EW and K-Othrine EC were tested against emerged adult females (F 0 generation) using ultra-low volume cold fogging (ULV) and thermal fogging (TF) delivery technology, both outdoors and indoors in Agboville, Côte d'Ivoire. Specifically, cages containing 20 mosquitoes each were placed at distances of 10, 25, 50, 75 and 100 m from the spraying line for outdoor spraying, and at ceiling, mid-height and floor levels for indoor house spraying. Knockdown and mortality were recorded at each checkpoint and compared by treatments., Results: Overall, Fludora Co-Max EW induced significantly higher knockdown and mortality effects in the wild insecticide-resistant Ae. aegypti and Cx. quinquefasciatus compared with K-Othrine EC. In both species, mortality rates with Fludora Co-Max EW were > 80% (up to 100%) with the ULV spray outdoors at each distance checkpoint (i.e. 10-100 m), and 100% with the ULV and TF sprays indoors at all checkpoints (i.e. ceiling, mid-height and floor). K-Othrine EC induced high mortality indoors (97.9-100%), whereas mortality outdoors rapidly declined in Ae. aegypti from 96.7% (10 m) to 36.7% (100 m) with the ULV spray, and from 85.0% (10 m) to 38.3% (100 m) with the TF spray. Fludora Co-Max EW spray applied as ULV spray outdoors had higher knockdown and higher killing effects on Ae. aegypti and Cx. quinquefasciatus than when applied as TF spray. Fludora Co-Max EW performed better against Cx. quinquefasciatus than against Ae. aegypti., Conclusions: Fludora Co-Max EW induced high mortality and knockdown effects against wild insecticide-resistant Ae. aegypti and Cx. quinquefasciatus Abidjan strains and performed better than K-Othrine EC. The presence of flupyradifurone and transfluthrin (with new and independent modes of action) and FFAST technology in the current Fludora Co-Max EW formulation appears to have broadened its killing capacity. Fludora Co-Max EW is thus an effective adulticide and may be a useful tool for Aedes and Culex mosquito and arbovirus control in endemic areas., (© 2023. The Author(s).)

Background: Due to the rapid expansion of pyrethroid-resistance in malaria vectors in Africa, Global Plan for Insecticide Resistance Management (GPIRM) has recommended the development of long-lasting insecticidal nets (LLINs), containing insecticide mixtures of active ingredients with different modes of action to mitigate resistance and improve LLIN efficacy. This good laboratory practice (GLP) study evaluated the efficacy of the chlorfenapyr and deltamethrin-coated PermaNet ® Dual, in comparison with the deltamethrin and synergist piperonyl butoxide (PBO)-treated PermaNet ® 3.0 and the deltamethrin-coated PermaNet ® 2.0, against wild free-flying pyrethroid-resistant Anopheles gambiae sensu lato (s.l.), in experimental huts in Tiassalé, Côte d'Ivoire (West Africa)., Methods: PermaNet ® Dual, PermaNet ® 3.0 and PermaNet ® 2.0, unwashed and washed (20 washes), were tested against free-flying pyrethroid-resistant An. gambiae s.l. in the experimental huts in Tiassalé, Côte d'Ivoire from March to August 2020. Complementary laboratory cone bioassays (daytime and 3-min exposure) and tunnel tests (nightly and 15-h exposure) were performed against pyrethroid-susceptible An. gambiae sensu stricto (s.s.) (Kisumu strain) and pyrethroid-resistant An. gambiae s.l. (Tiassalé strain)., Results: PermaNet ® Dual demonstrated significantly improved efficacy, compared to PermaNet ® 3.0 and PermaNet ® 2.0, against the pyrethroid-resistant An. gambiae s.l. Indeed, the experimental hut trial data showed that the mortality and blood-feeding inhibition in the wild pyrethroid-resistant An. gambiae s.l. were overall significantly higher with PermaNet ® Dual compared with PermaNet ® 3.0 and PermaNet ® 2.0, for both unwashed and washed samples. The mortality with unwashed and washed samples were 93.6 ± 0.2% and 83.2 ± 0.9% for PermaNet ® Dual, 37.5 ± 2.9% and 14.4 ± 3.9% for PermaNet ® 3.0, and 7.4 ± 5.1% and 11.7 ± 3.4% for PermaNet ® 2.0, respectively. Moreover, unwashed and washed samples produced the respective percentage blood-feeding inhibition of 41.4 ± 6.9% and 43.7 ± 4.8% with PermaNet ® Dual, 51.0 ± 5.7% and 9.8 ± 3.6% with PermaNet ® 3.0, and 12.8 ± 4.3% and - 13.0 ± 3.6% with PermaNet ® 2.0. Overall, PermaNet ® Dual also induced higher or similar deterrence, exophily and personal protection when compared with the standard PermaNet ® 3.0 and PermaNet ® 2.0 reference nets, with both unwashed and washed net samples. In contrast to cone bioassays, tunnel tests predicted the efficacy of PermaNet ® Dual seen in the current experimental hut trial., Conclusion: The deltamethrin-chlorfenapyr-coated PermaNet ® Dual induced a high efficacy and performed better than the deltamethrin-PBO PermaNet ® 3.0 and the deltamethrin-only PermaNet ® 2.0, testing both unwashed and 20 times washed samples against the pyrethroid-susceptible and resistant strains of An. gambiae s.l. The inclusion of chlorfenapyr with deltamethrin in PermaNet ® Dual net greatly improved protection and control of pyrethroid-resistant An. gambiae populations. PermaNet ® Dual thus represents a promising tool, with a high potential to reduce malaria transmission and provide community protection in areas compromised by mosquito vector resistance to pyrethroids., (© 2023. The Author(s).)

The novel coronavirus disease 2019 (COVID-19) is one of the biggest public health crises globally. Although Africa did not display the worst-case scenario compared to other continents, fears were still at its peak since Africa was already suffering from a heavy load of other life-threatening infectious diseases such as HIV/AIDS and malaria. Other factors that were anticipated to complicate Africa's outcomes include the lack of resources for diagnosis and contact tracing along with the low capacity of specialized management facilities per capita . The current review aims at assessing and generating discussions on the realities, and pros and cons of the WHO COVID-19 interim guidance 2020.5 considering the known peculiarities of the African continent. A comprehensive evaluation was done for COVID-19-related data published across PubMed and Google Scholar (date of the last search: August 17, 2020) with emphasis on clinical management and psychosocial aspects. Predefined filters were then applied in data screening as detailed in the methods. Specifically, we interrogated the WHO 2020.5 guideline viz-a-viz health priority and health financing in Africa, COVID-19 case contact tracing and risk assessment, clinical management of COVID-19 cases as well as strategies for tackling stigmatization and psychosocial challenges encountered by COVID-19 survivors. The outcomes of this work provide links between these vital sub-themes which may impact the containment and management of COVID-19 cases in Africa in the long-term. The chief recommendation of the current study is the necessity of prudent filtration of the global findings along with regional modelling of the global care guidelines for acting properly in response to this health threat on the regional level without exposing our populations to further unnecessary adversities., Competing Interests: 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., (© 2021 The Author(s).)

The evolving nature of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has necessitated periodic revisions of COVID-19 patient treatment and discharge guidelines. Since the identification of the first COVID-19 cases in November 2019, the World Health Organization (WHO) has played a crucial role in tackling the country-level pandemic preparedness and patient management protocols. Among others, the WHO provided a guideline on the clinical management of COVID-19 patients according to which patients can be released from isolation centers on the 10th day following clinical symptom manifestation, with a minimum of 72 additional hours following the resolution of symptoms. However, emerging direct evidence indicating the possibility of viral shedding 14 days after the onset of symptoms called for evaluation of the current WHO discharge recommendations. In this review article, we carried out comprehensive literature analysis of viral shedding with specific focus on the duration of viral shedding and infectivity in asymptomatic and symptomatic (mild, moderate, and severe forms) COVID-19 patients. Our literature search indicates that even though, there are specific instances where the current protocols may not be applicable ( such as in immune-compromised patients there is no strong evidence to contradict the current WHO discharge criteria., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Badu, Oyebola, Zahouli, Fagbamigbe, de Souza, Dukhi, Amankwaa, Tolba, Sylverken, Mosi, Mante, Matoke-Muhia and Goonoo.)