13 results on '"Kamugisha, Erasmus"'
Search Results
2. Microsatellites reveal high polymorphism and high potential for use in anti-malarial efficacy studies in areas with different transmission intensities in mainland Tanzania
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Ishengoma, Deus S., Mandara, Celine I., Madebe, Rashid A., Warsame, Marian, Ngasala, Billy, Kabanywanyi, Abdunoor M., Mahende, Muhidin K., Kamugisha, Erasmus, Kavishe, Reginald A., Muro, Florida, Mandike, Renata, Mkude, Sigsbert, Chacky, Frank, Njau, Ritha, Martin, Troy, Mohamed, Ally, Bailey, Jeffrey A., and Fola, Abebe A.
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- 2024
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3. Trends of Plasmodium falciparum molecular markers associated with resistance to artemisinins and reduced susceptibility to lumefantrine in Mainland Tanzania from 2016 to 2021
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Bakari, Catherine, Mandara, Celine I., Madebe, Rashid A., Seth, Misago D., Ngasala, Billy, Kamugisha, Erasmus, Ahmed, Maimuna, Francis, Filbert, Bushukatale, Samwel, Chiduo, Mercy, Makene, Twilumba, Kabanywanyi, Abdunoor M., Mahende, Muhidin K., Kavishe, Reginald A., Muro, Florida, Mkude, Sigsbert, Mandike, Renata, Molteni, Fabrizio, Chacky, Frank, Bishanga, Dunstan R., Njau, Ritha J. A., Warsame, Marian, Kabula, Bilali, Nyinondi, Ssanyu S., Lucchi, Naomi W., Talundzic, Eldin, Venkatesan, Meera, Moriarty, Leah F., Serbantez, Naomi, Kitojo, Chonge, Reaves, Erik J., Halsey, Eric S., Mohamed, Ally, Udhayakumar, Venkatachalam, and Ishengoma, Deus S.
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- 2024
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4. Why some sites are responding better to anti-malarial interventions? A case study from western Kenya.
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Kapesa, Anthony, Kweka, Eliningaya J, Atieli, Harrysone, Kamugisha, Erasmus, Zhou, Guofa, Githeko, Andrew K, and Yan, Guiyun
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Animals ,Humans ,Plasmodium falciparum ,Malaria ,Bites and Stings ,Pyrethrins ,Nitriles ,Antimalarials ,Insecticides ,Cross-Sectional Studies ,Disease Vectors ,Population Density ,Mosquito Control ,Insecticide Resistance ,Geography ,Kenya ,Insecticide-Treated Bednets ,Climate Change ,Early Medical Intervention ,Mosquito Vectors ,Climate variability ,Insecticide resistance ,Malaria intervention ,Species shift ,Western Kenya ,Tropical Medicine ,Medical Microbiology ,Public Health and Health Services ,Microbiology - Abstract
BackgroundIn sub-Saharan Africa, malaria interventions over the last decades have been successful in reducing both mortality and morbidity. In western Kenya however some areas experience contrasting outcomes of the ongoing interventions while the causes for this observation remains not yet clearly known.MethodsThe WHO insecticide (deltamethrin) susceptibility test of the common malaria vectors was studied. Multiple surveys on household use and hospital prescriptions of antimalarial drugs from 2003 to 2015 were done. Along with this, cross sectional surveys on their availability in the local drug dispensing outlets were also done in 2015. Monthly precipitations and air temperature data was collected along with systematic review on abundance and composition of common malaria vectors in the study area before and during interventions. The above factors were used to explain the possible causes of contrasting outcome of malaria interventions between the three study sites.ResultsAreas with malaria resurgence or sustained high transmission (Kombewa and Marani) showed higher composition of Anopheles funestus sensu lato (s.l.) than the previously abundant Anopheles gambiae sensu stricto (s.s.) and the later had higher composition to an area with a sustained infection decline (Iguhu). Anopheles gambiae s.l. from Kombewa showed highest resistance (50% mortality) upon exposure to WHO deltamethrin discriminating dosage of 0.75% while those from Marani and Iguhu had reduced resistance status (both had a mean mortality of 91%). Sampled An. funestus s.l. from Marani were also highly resistant to deltamethrin as 57% of the exposed vectors survived. An increasing of mean air temperature by 2 °C was noted for Marani and Iguhu from 2013 to 2015 and was accompanied by an increased rainfall at Marani. Community drug use and availability in selling outlets along with prescription in hospitals were not linked to the struggling control of the disease.ConclusionsThe malaria vector species composition shift, insecticide resistance and climatic warming were the likely cause of the contrasting outcome of malaria intervention in western Kenya. Surveillance of malaria parasite and vector dynamics along with insecticide resistance and vector biting behaviour monitoring are highly recommended in these areas.
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- 2017
5. Haematological consequences of acute uncomplicated falciparum malaria: a WorldWide Antimalarial Resistance Network pooled analysis of individual patient data
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Mansoor, Rashid, Commons, Robert J, Douglas, Nicholas M, Abuaku, Benjamin, Achan, Jane, Adam, Ishag, Adjei, George O, Adjuik, Martin, Alemayehu, Bereket H, Allan, Richard, Allen, Elizabeth N, Anvikar, Anupkumar R, Arinaitwe, Emmanuel, Ashley, Elizabeth A, Ashurst, Hazel, Asih, Puji BS, Bakyaita, Nathan, Barennes, Hubert, Barnes, Karen I, Basco, Leonardo, Bassat, Quique, Baudin, Elisabeth, Bell, David J, Bethell, Delia, Bjorkman, Anders, Boulton, Caroline, Bousema, Teun, Brasseur, Philippe, Bukirwa, Hasifa, Burrow, Rebekah, Carrara, Verena I, Cot, Michel, D'Alessandro, Umberto, Das, Debashish, Das, Sabyasachi, Davis, Timothy ME, Desai, Meghna, Djimde, Abdoulaye A, Dondorp, Arjen M, Dorsey, Grant, Drakeley, Chris J, Duparc, Stephan, Espie, Emmanuelle, Etard, Jean-Francois, Falade, Catherine, Faucher, Jean Francois, Filler, Scott, Fogg, Carole, Fukuda, Mark, Gaye, Oumar, Genton, Blaise, Rahim, Awab Ghulam, Gilayeneh, Julius, Gonzalez, Raquel, Grais, Rebecca F, Grandesso, Francesco, Greenwood, Brian, Grivoyannis, Anastasia, Hatz, Christoph, Hodel, Eva Maria, Humphreys, Georgina S, Hwang, Jimee, Ishengoma, Deus, Juma, Elizabeth, Kachur, S Patrick, Kager, Piet A, Kamugisha, Erasmus, Kamya, Moses R, Karema, Corine, Kayentao, Kassoum, Kazienga, Adama, Kiechel, Jean-Rene, Kofoed, Poul-Erik, Koram, Kwadwo, Kremsner, Peter G, Lalloo, David G, Laman, Moses, Lee, Sue J, Lell, Bertrand, Maiga, Amelia W, Martensson, Andreas, Mayxay, Mayfong, Mbacham, Wilfred, McGready, Rose, Menan, Herve, Menard, Didier, Mockenhaupt, Frank, Moore, Brioni R, Muller, Olaf, Nahum, Alain, Ndiaye, Jean-Louis, Newton, Paul N, Ngasala, Billy E, Nikiema, Frederic, Nji, Akindeh M, Noedl, Harald, Nosten, Francois, Ogutu, Bernhards R, Ojurongbe, Olusola, Osorio, Lyda, Ouedraogo, Jean-Bosco, Owusu-Agyei, Seth, Pareek, Anil, Penali, Louis K, Piola, Patrice, Plucinski, Mateusz, Premji, Zul, Ramharter, Michael, Richmond, Caitlin L, Rombo, Lars, Rosenthal, Philip J, Salman, Sam, Same-Ekobo, Albert, Sibley, Carol, Sirima, Sodiomon B, Smithuis, Frank M, Some, Fabrice A, Staedke, Sarah G, Starzengruber, Peter, Strub-Wourgaft, Nathalie, Sutanto, Inge, Swarthout, Todd D, Syafruddin, Din, Talisuna, Ambrose O, Taylor, Walter R, Temu, Emmanuel A, Thwing, Julie I, Tinto, Halidou, Tjitra, Emiliana, Toure, Offianan A, Tran, T Hien, Ursing, Johan, Valea, Innocent, Valentini, Giovanni, van Vugt, Michele, von Seidlein, Lorenz, Ward, Stephen A, Were, Vincent, White, Nicholas J, Woodrow, Charles J, Yavo, William, Yeka, Adoke, Zongo, Issaka, Simpson, Julie A, Guerin, Philippe J, Stepniewska, Kasia, Price, Ric N, Roper, Cally, Resistance, WorldWide Antimalarial, WorldWide Antimalarial Resistance Network Falciparum Haematology Study Group, Vecteurs - Infections tropicales et méditerranéennes (VITROME), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut de Recherche Biomédicale des Armées [Brétigny-sur-Orge] (IRBA), Epidémiologie des Maladies Chroniques en zone tropicale (EpiMaCT), CHU Limoges-Institut d'Epidémiologie Neurologique et de Neurologie Tropicale-Institut National de la Santé et de la Recherche Médicale (INSERM)-OmégaHealth (ΩHealth), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Group, WorldWide Antimalarial Resistance Network Falciparum Haematology Study, Mansoor, R, Ashley, EA, Ashurst, H, Burrow, R, Carrara, VI, Das, D, Dondorp, AM, Humphreys, GS, Lee, SJ, Mayxay, M, McGready, R, Newton, PN, Nosten, F, Richmond, CL, Sibley, C, Smithuis, FM, Taylor, WR, Tran, TH, von Seidlein, L, White, NJ, Woodrow, CJ, Guerin, PJ, Stepniewska, K, Price, RN, AII - Infectious diseases, Intensive Care Medicine, Infectious diseases, APH - Global Health, and APH - Quality of Care
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Infectious Medicine ,Plasmodium falciparum ,wh_120 ,Infektionsmedicin ,Severe anaemia ,Parasitemia ,wa_530 ,Antimalarials ,Non-artemisinin-based therapy ,[SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,parasitic diseases ,qv_256 ,Humans ,[SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology ,Malaria, Falciparum ,Child ,[SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases ,Pooled analysis of individual patient data ,Anemia ,Public Health, Global Health, Social Medicine and Epidemiology ,General Medicine ,Artemisinin-based therapy ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Malaria ,wc_750 ,Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi ,lnfectious Diseases and Global Health Radboud Institute for Health Sciences [Radboudumc 4] ,[SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,Haemoglobin - Abstract
Background Plasmodium falciparum malaria is associated with anaemia-related morbidity, attributable to host, parasite and drug factors. We quantified the haematological response following treatment of uncomplicated P. falciparum malaria to identify the factors associated with malarial anaemia. Methods Individual patient data from eligible antimalarial efficacy studies of uncomplicated P. falciparum malaria, available through the WorldWide Antimalarial Resistance Network data repository prior to August 2015, were pooled using standardised methodology. The haematological response over time was quantified using a multivariable linear mixed effects model with nonlinear terms for time, and the model was then used to estimate the mean haemoglobin at day of nadir and day 7. Multivariable logistic regression quantified risk factors for moderately severe anaemia (haemoglobin < 7 g/dL) at day 0, day 3 and day 7 as well as a fractional fall ≥ 25% at day 3 and day 7. Results A total of 70,226 patients, recruited into 200 studies between 1991 and 2013, were included in the analysis: 50,859 (72.4%) enrolled in Africa, 18,451 (26.3%) in Asia and 916 (1.3%) in South America. The median haemoglobin concentration at presentation was 9.9 g/dL (range 5.0–19.7 g/dL) in Africa, 11.6 g/dL (range 5.0–20.0 g/dL) in Asia and 12.3 g/dL (range 6.9–17.9 g/dL) in South America. Moderately severe anaemia (Hb < 7g/dl) was present in 8.4% (4284/50,859) of patients from Africa, 3.3% (606/18,451) from Asia and 0.1% (1/916) from South America. The nadir haemoglobin occurred on day 2 post treatment with a mean fall from baseline of 0.57 g/dL in Africa and 1.13 g/dL in Asia. Independent risk factors for moderately severe anaemia on day 7, in both Africa and Asia, included moderately severe anaemia at baseline (adjusted odds ratio (AOR) = 16.10 and AOR = 23.00, respectively), young age (age < 1 compared to ≥ 12 years AOR = 12.81 and AOR = 6.79, respectively), high parasitaemia (AOR = 1.78 and AOR = 1.58, respectively) and delayed parasite clearance (AOR = 2.44 and AOR = 2.59, respectively). In Asia, patients treated with an artemisinin-based regimen were at significantly greater risk of moderately severe anaemia on day 7 compared to those treated with a non-artemisinin-based regimen (AOR = 2.06 [95%CI 1.39–3.05], p < 0.001). Conclusions In patients with uncomplicated P. falciparum malaria, the nadir haemoglobin occurs 2 days after starting treatment. Although artemisinin-based treatments increase the rate of parasite clearance, in Asia they are associated with a greater risk of anaemia during recovery.
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- 2022
6. Temporal distribution of Plasmodium falciparum recrudescence following artemisinin-based combination therapy: an individual participant data meta-analysis
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Dahal, Prabin, Simpson, Julie Anne, Abdulla, Salim, Achan, Jane, Adam, Ishag, Agarwal, Aarti, Allan, Richard, Anvikar, Anupkumar R., Ashley, Elizabeth A., Bassat, Quique, Borrmann, Steffen, Bousema, Teun, Bukirwa, Hasifa, Carrara, Verena, I, Corsi, Marco, D'Alessandro, Umberto, Davis, Timothy M. E., Deloron, Philippe, Desai, Meghna, Dimbu, Pedro Rafael, Djalle, Djibrine, Djimde, Abdoulaye, Dorsey, Grant, Drakeley, Chris J., Duparc, Stephan, Edstein, Michael D., Espie, Emmanuelle, Faiz, Abul, Falade, Catherine, Fanello, Caterina, Faucher, Jean-Francois, Faye, Babacar, Fortes, Filomeno de Jesus, Gadalla, Nahla B., Gaye, Oumar, Gil, J. Pedro, Gilayeneh, Julius, Greenwood, Brian, Grivoyannis, Anastasia, Hien, Tran Tinh, Hwang, Jimee, Janssens, Bart, Juma, Elizabeth, Kamugisha, Erasmus, Karema, Corine, Karunajeewa, Harin A., Kiechel, Jean R., Kironde, Fred, Kofoed, Poul-Erik, Kremsner, Peter G., Lee, Sue J., Marsh, Kevin, Mårtensson, Andreas, Mayxay, Mayfong, Menan, Herve, Mens, Petra, Mutabingwa, Theonest K., Ndiaye, Jean-Louis, Ngasala, Billy, Noedl, Harald, Nosten, Francois, Offianan, Andre Toure, Ogutu, Bernhards R., Olliaro, Piero L., Ouedraogo, Jean Bosco, Piola, Patrice, Plowe, Christopher, V, Plucinski, Mateusz M., Pratt, Oliver James, Premji, Zulfikarali, Ramharter, Michael, Rogier, Christophe, Vitare, Primum, Rombo, Lars, Rosenthal, Philip J., Sibley, Carol, Sirima, Sodiomon, Smithuis, Frank, Staedke, Sarah G., Sutanto, Inge, Talisuna, Ambrose Otau, Tarning, Joel, Taylor, Walter R. J., Temu, Emmanuel, Thriemer, Kamala, Thuy-Nhien, Nguyen, Udhayakumar, Venkatachalam, Ursing, Johan D., van Herp, Michel, van Lenthe, Marit, van Vugt, Michele, William, Yavo, Winnips, Cornelis, Zaloumis, Sophie, Zongo, Issaka, White, Nick J., Guerin, Philippe J., Stepniewska, Kasia, Price, Ric N., Arinaitwe, Emmanuel, and Group, WorldWide Antimalarial Resistance Network Methodology Study
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Infectious Medicine ,Efficacy ,Follow-up ,Recrudescence ,Artemether, Lumefantrine Drug Combination ,Plasmodium falciparum ,Infektionsmedicin ,Distribution ,Artemisinins ,Malaria ,Antimalarials ,lnfectious Diseases and Global Health Radboud Institute for Health Sciences [Radboudumc 4] ,Infectious Diseases ,Recurrence ,Child, Preschool ,Humans ,Parasitology ,Artemether ,Child - Abstract
Background The duration of trial follow-up affects the ability to detect recrudescent infections following anti-malarial treatment. The aim of this study was to explore the proportions of recrudescent parasitaemia as ascribed by genotyping captured at various follow-up time-points in treatment efficacy trials for uncomplicated Plasmodium falciparum malaria. Methods Individual patient data from 83 anti-malarial efficacy studies collated in the WorldWide Antimalarial Resistance Network (WWARN) repository with at least 28 days follow-up were available. The temporal and cumulative distributions of recrudescence were characterized using a Cox regression model with shared frailty on study-sites. Fractional polynomials were used to capture non-linear instantaneous hazard. The area under the density curve (AUC) of the constructed distribution was used to estimate the optimal follow-up period for capturing a P. falciparum malaria recrudescence. Simulation studies were conducted based on the constructed distributions to quantify the absolute overestimation in efficacy due to sub-optimal follow-up. Results Overall, 3703 recurrent infections were detected in 60 studies conducted in Africa (15,512 children aged 48 mg/kg total piperaquine (PIP) dose and 9% [95% CI 0–22%] in those treated with ≤ 48 mg/kg PIP dose. In absolute terms, the simulation study found that trials limited to 28 days follow-up following AL underestimated the risk of recrudescence by a median of 2.8 percentage points compared to day 63 estimates and those limited to 42 days following DP underestimated the risk of recrudescence by a median of 2.0 percentage points compared to day 42 estimates. The analysis was limited by few clinical trials following patients for longer than 42 days (9 out of 83 trials) and the imprecision of PCR genotyping which overcalls recrudescence in areas of higher transmission biasing the later distribution. Conclusions Restricting follow-up of clinical efficacy trials to day 28 for AL and day 42 for DP will miss a proportion of late recrudescent treatment failures but will have a modest impact in derived efficacy. The results highlight that as genotyping methods improve consideration should be given for trials with longer duration of follow-up to detect early indications of emerging drug resistance.
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- 2022
7. Plasmodium falciparum Merozoite Surface Proteins Polymorphisms and Treatment Outcomes among Patients with Uncomplicated Malaria in Mwanza, Tanzania.
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Marwa, Karol J., Lyimo, Eric, Konje, Eveline T., Kapesa, Anthony, Kamugisha, Erasmus, and Swedberg, Göte
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PLASMODIUM falciparum ,TREATMENT effectiveness ,MALARIA ,GENETIC variation ,INFECTIOUS disease transmission - Abstract
Background. The severity of malaria infection depends on the host, parasite and environmental factors. Merozoite surface protein (msp) diversity determines transmission dynamics, P. falciparum immunity evasion, and pathogenesis or virulence. There is limited updated information on P. falciparum msp polymorphisms and their impact on artemether-lumefantrine treatment outcomes in Tanzania. Therefore, this study is aimed at examining msp genetic diversity and multiplicity of infection (MOI) among P. falciparum malaria patients. The influence of MOI on peripheral parasite clearance and adequate clinical and parasitological response (ACPR) was also assessed. Methods. Parasite DNA was extracted from dried blood spots according to the manufacture's protocol. Primary and nested PCR were performed. The PCR products for both the block 2 region of msp1 and the block 3 regions of msp2 genes and their specific allelic families were visualized on a 2.5% agarose gel. Results. The majority of the isolates, 58/102 (58.8%) for msp1 and 69/115 (60.1%) for msp2, harboured more than one parasite genotypes. For the msp1 gene, K1 was the predominant allele observed (75.64%), whereas RO33 occurred at the lowest frequency (43.6%). For the msp2 gene, the 3D7 allele was observed at a higher frequency (81.7%) than the FC27 allele (76.9%). The MOIs were 2.44 for msp1 and 2.27 for msp2 (p = 0.669). A significant correlation between age and multiplicity of infection (MOI) for msp1 or MOI for msp2 was not established in this study (rho = 0.074, p = 0.521 and rho = −0.129, p = 0.261 , respectively). Similarly, there was no positive correlation between parasite density at day 1 and MOI for both msp1 (rho = 0.113, p = 0.244) and msp2 (rho = 0.043, p = 0.712). The association between MOI and ACPR was not observed for either msp1 or mps2 (p = 0.776 and 0.296, respectively). Conclusions. This study reports high polyclonal infections, MOI and allelic frequencies for both msp1 and msp2. There was a lack of correlation between MOI and ACPR. However, a borderline significant correlation was observed between day 2 parasitaemia and MOI. [ABSTRACT FROM AUTHOR]
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- 2022
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8. Therapeutic efficacy of artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine in the treatment of uncomplicated Plasmodium falciparum malaria in Sub-Saharan Africa: A systematic review and meta-analysis.
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Marwa, Karol, Kapesa, Anthony, Baraka, Vito, Konje, Evelyne, Kidenya, Benson, Mukonzo, Jackson, Kamugisha, Erasmus, and Swedberg, Gote
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MALARIA ,ONLINE databases ,TREATMENT effectiveness ,PLASMODIUM falciparum ,ARTEMISININ derivatives ,META-analysis - Abstract
Background: Sub-Saharan Africa has the highest burden of malaria in the world. Artemisinin-based combination therapies (ACTs) have been the cornerstone in the efforts to reduce the global burden of malaria. In the effort to facilitate early detection of resistance for artemisinin derivatives and partner drugs, WHO recommends monitoring of ACT's efficacy in the malaria endemic countries. The present systematic meta-analysis study summarises the evidence of therapeutic efficacy of the commonly used artemisinin-based combinations for the treatment of uncomplicated P. falciparum malaria in Sub-Saharan Africa after more than a decade since the introduction of the drugs. Methods: Fifty two studies carried out from 2010 to 2020 on the efficacy of artemether-lumefantrine or dihydro-artemisinin piperaquine or artesunate amodiaquine in patients with uncomplicated P. falciparum malaria in Sub-Saharan Africa were searched for using the Google Scholar, Cochrane Central Register of controlled trials (CENTRAL), PubMed, Medline, LILACS, and EMBASE online data bases. Data was extracted by two independent reviewers. Random analysis effect was performed in STATA 13. Heterogeneity was established using I
2 statistics. Results: Based on per protocol analysis, unadjusted cure rates in malaria infected patients treated with artemether-lumefantrine (ALU), artesunate-amodiaquine (ASAQ) and dihydroartemisinin-piperaquine (DHP) were 89%, 94% and 91% respectively. However, the cure rates after PCR correction were 98% for ALU, 99% for ASAQ and 99% for DHP. Conclusion: The present meta-analysis reports the overall high malaria treatment success for artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine above the WHO threshold value in Sub-Saharan Africa. [ABSTRACT FROM AUTHOR]- Published
- 2022
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9. Describing the current status of Plasmodium falciparum population structure and drug resistance within mainland Tanzania using molecular inversion probes.
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Moser, Kara A., Madebe, Rashid A., Aydemir, Ozkan, Chiduo, Mercy G., Mandara, Celine I., Rumisha, Susan F., Chaky, Frank, Denton, Madeline, Marsh, Patrick W., Verity, Robert, Watson, Oliver J., Ngasala, Billy, Mkude, Sigsbert, Molteni, Fabrizio, Njau, Ritha, Warsame, Marian, Mandike, Renata, Kabanywanyi, Abdunoor M., Mahende, Muhidin K., and Kamugisha, Erasmus
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MOLECULAR probes ,PLASMODIUM falciparum ,DRUG resistance ,PLASMODIUM vivax ,POPULATION dynamics ,POPULATION ,PLASMODIUM - Abstract
High‐throughput Plasmodium genomic data is increasingly useful in assessing prevalence of clinically important mutations and malaria transmission patterns. Understanding parasite diversity is important for identification of specific human or parasite populations that can be targeted by control programmes, and to monitor the spread of mutations associated with drug resistance. An up‐to‐date understanding of regional parasite population dynamics is also critical to monitor the impact of control efforts. However, this data is largely absent from high‐burden nations in Africa, and to date, no such analysis has been conducted for malaria parasites in Tanzania countrywide. To this end, over 1,000 P. falciparum clinical isolates were collected in 2017 from 13 sites in seven administrative regions across Tanzania, and parasites were genotyped at 1,800 variable positions genome‐wide using molecular inversion probes. Population structure was detectable among Tanzanian P. falciparum parasites, approximately separating parasites from the northern and southern districts and identifying genetically admixed populations in the north. Isolates from nearby districts were more likely to be genetically related compared to parasites sampled from more distant districts. Known drug resistance mutations were seen at increased frequency in northern districts (including two infections carrying pfk13‐R561H), and additional variants with undetermined significance for antimalarial resistance also varied by geography. Malaria Indicator Survey (2017) data corresponded with genetic findings, including average region‐level complexity‐of‐infection and malaria prevalence estimates. The parasite populations identified here provide important information on extant spatial patterns of genetic diversity of Tanzanian parasites, to which future surveys of genetic relatedness can be compared. [ABSTRACT FROM AUTHOR]
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- 2021
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10. Detecting adenosine triphosphatase 6 point mutations that may be associated with Plasmodium falciparum resistance to artemisinin : prevalence at baseline, before policy change in Uganda
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Kamugisha, Erasmus, Sendagire, Hakim, KadduMukasa, Mark, Enweji, Nizar, Gheysari, Fatheme, Swedberg, Göte, and Kironde, Fred
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PfATP5 ,resistance ,artemisinin ,SERCA ,parasitic diseases ,Plasmodium falciparum ,Uganda - Abstract
The artemisinin based combination therapy (ACT) of artemether and lumefantrine (Co-artem) has recently replaced chloroquine and fansidar as the first line treatment policy drug in Uganda. It is necessary to develop practical procedures to monitor the likely emergence and spread of artemisinin resistant P. falciparum strains. We have analyzed the genotypes of PfATP6 in parasites from 300 stored filter paper samples from malaria patients who were diagnosed and treated in the years 1999 to 2004 at three field sites in Uganda. This is a period just prior to introduction of Co-artem. In order to develop a simple molecular procedure for mutation detection, regions of PfATP6 encoding protein domains important in artemisinin binding was amplified by nested PCR. Three DNA products, which together contain most of the coding region of amino acids located within the putative active site of pfATP6 were readily amplified. The amplified DNA was digested by restriction enzymes and the fragments sized by agarose gel electrophoresis. For the important codons 260, 263 and 769, methods using engineered restriction sites were employed. We did not find mutations at codons for the key residues Lys 260, Leu263, Gln266, Ser769 and Asn1039. Nucleotide sequencing of pfATPase6 gene DNA from at least 15 clinical isolates confirmed the above findings and suggested that mutations at these amino acid residues have not emerged in our study sites.
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- 2011
11. Identification of large variation in pfcrt, pfmdr-1 and pfubp-1 markers in Plasmodium falciparum isolates from Ethiopia and Tanzania.
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Golassa, Lemu, Kamugisha, Erasmus, Ishengoma, Deus S., Baraka, Vito, Shayo, Alex, Baliraine, Frederick N., Enweji, Nizar, Erko, Berhanu, Aseffa, Abraham, Choy, Angel, and Swedberg, Göte
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PLASMODIUM falciparum , *MALARIA , *DRUG resistance , *ANTIMALARIALS , *ARTEMISININ , *GENETIC markers , *POLYMERASE chain reaction , *PROTOZOA - Abstract
Background: Plasmodium falciparum resistance to anti-malarials is a major drawback in effective malaria control and elimination globally. Artemisinin-combination therapy (ACT) is currently the key first-line treatment for uncomplicated falciparum malaria. Plasmodium falciparum genetic signatures at pfmdr-1, pfcrt, and pfubp-1 loci are known to modulate in vivo and in vitro parasite response to ACT. The objective of this study was to assess the distribution of these resistance gene markers in isolates collected from different malaria transmission intensity in Ethiopia and Tanzania. Methods: Plasmodium falciparum clinical isolates were collected from different regions of Ethiopia and Tanzania. Genetic polymorphisms in the genes pfcrt, pfmdr-1 and pfubp-1 were analysed by PCR and sequencing. Frequencies of the different alleles in the three genes were compared within and between regions, and between the two countries. Results: The majority of the isolates from Ethiopia were mutant for the pfcrt 76 and wild-type for pfmdr-1 86. In contrast, the majority of the Tanzanian samples were wild-type for both pfcrt and pfmdr-1 loci. Analysis of a variable linker region in pfmdr-1 showed substantial variation in isolates from Tanzania as compared to Ethiopian isolates that had minimal variation. Direct sequencing of the pfubp-1 region showed that 92.8% (26/28) of the Ethiopian isolates had identical genome sequence with the wild type reference P. falciparum strain 3D7. Of 42 isolates from Tanzania, only 13 (30.9%) had identical genome sequences with 3D7. In the Tanzanian samples, 10 variant haplotypes were identified. Conclusion: The majority of Ethiopian isolates carried the main marker for chloroquine (CQ) resistance, while the majority of the samples from Tanzania carried markers for CQ susceptibility. Polymorphic genes showed substantially more variation in Tanzanian isolates. The low variability in the polymorphic region of pfmdr-1 in Ethiopia may be a consequence of low transmission intensity as compared to high transmission intensity and large variations in Tanzania. [ABSTRACT FROM AUTHOR]
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- 2015
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12. Lumefantrine plasma concentrations in uncontrolled conditions among patients treated with artemether-lumefantrine for uncomplicated plasmodium falciparum malaria in Mwanza, Tanzania.
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Marwa, Karol J, Liwa, Anthony C, Konje, Eveline T, Mwita, Stanley, Kamugisha, Erasmus, and Swedberg, Göte
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HIGH performance liquid chromatography , *PLASMODIUM falciparum , *MALARIA , *DRUG monitoring , *DRUG efficacy - Abstract
Therapeutic efficacy of artemether-lumefantrine is highly dependent on adequate systemic exposure to the partner drug lumefantrine particularly day 7 lumefantrine plasma concentration. There has been contradicting findings on the role of the cut-off values in predicting treatment outcomes among malaria patients in malaria endemic regions. This study assesses the day 3 and 7 lumefantrine plasma concentrations including related determinant factors and their influence on treatment outcomes among treated Tanzanian children and adults in uncontrolled conditions (real life condition). Data was nested from an efficacy study employing the WHO protocol, 2015 for monitoring antimalarial drug efficacy. Lumefantrine plasma concentration was measured by high performance liquid chromatography with ultraviolet (HPLC-UV). Results: Lumefantrine plasma concentrations below 175ng/ml and 200ng/ml on day 3 and 7 did not affect adequate clinical and parasitological response (ACPR) and recurrence of infection (p = 0.428 and 0.239 respectively). Age and baseline parasitemia were not associated to day 3 median lumefantrine plasma concentrations (p = 0.08 and 0.31 respectively) and day 7 lumefantrine plasma concentrations (p = 0.07 and 0.41 respectively). However, the day 3 and day 7 lumefantrine plasma concentrations were significantly higher in males compared to females (p = 0.03 and 0.042 respectively). Lumefantrine plasma concentrations below cut-off points (175ng/ml and 200ng/ml) on day 3 and 7 did not influence treatment outcomes. [ABSTRACT FROM AUTHOR]
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- 2022
- Full Text
- View/download PDF
13. Artemether–lumefantrine and dihydroartemisinin–piperaquine treatment outcomes among children infected with uncomplicated Plasmodium falciparum malaria in Mwanza, Tanzania.
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Marwa, Karol J., Konje, Eveline T., Kapesa, Anthony, Kamugisha, Erasmus, Mwita, Stanley, and Swedberg, Göte
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TREATMENT effectiveness , *MALARIA , *PLASMODIUM falciparum , *TREATMENT failure , *DRUG utilization - Abstract
Background: Artemisinin based combination therapies (ACTs) have been a cornerstone in the treatment of malaria in the world. A rapid decline in dihydroartemisinin piperaquine (DHP) and artemether lumefantrine (ALU) efficacies has been reported in some parts of South East Asia, the historical epicenter for the antimalarial drug resistance. Prolonged drug use is associated with selection of resistant parasites due to exposure to inadequate drug levels hence effects on treatment outcomes in malaria. ALU and DHP are used as first line and alternative first line, respectively, in Tanzania. This study was carried in Igombe, Tanzania to assess the efficacies of ALU and DHP in routine treatment of uncomplicated malaria among children. Methods: This was a prospective study involving children up to 10 years and followed up for 28 and 35 days as per the WHO protocol, 2015 for monitoring antimalarial drug efficacy. The primary end points were crude and adjusted Adequate Clinical and Parasitological Response (ACPR), parasite clearance rate and reported adverse events. Results: A total of 205 children with uncomplicated malaria were enrolled. One hundred and sixteen participants were treated with ALU, while 89 participants were treated with DHP. Two participants in the ALU group were lost within the 24 h of follow-up. The PCR unadjusted ACPR was108 (94.7%) for ALU and 88 (98.9%) for DHP, while the PCR adjusted ACPR was 109(95.6%) and 88(98.9%) for ALU and DHP, respectively, at 28 day follow-up. No treatment failure was observed in both groups. Cumulative risk of recurrent parasitemia was similar in both groups (p = 0.32). Age and parasite density were strong predictors for persistent day 1 parasitemia (p = 0.034 and 0.026, respectively). Nausea and vomiting, abdominal pain and headache were the most clinical adverse events reported in both groups of patients. Conclusion: The present study shows that ALU and DHP are still efficacious after more than a decade of use with PCR corrected efficacies greater than 95% implying a failure rate less than 5% which is below the WHO minimum threshold requirement for recommendation of a change in the treatment policy. Both drugs were well tolerated with no major adverse events reported. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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