Dataset Information

Selection of drug resistance-mediating Plasmodium falciparum genetic polymorphisms by seasonal malaria chemoprevention in Burkina Faso.

ABSTRACT: Seasonal malaria chemoprevention (SMC), with regular use of amodiaquine plus sulfadoxine-pyrimethamine (AQ/SP) during the transmission season, is now a standard malaria control measure in the Sahel subregion of Africa. Another strategy under study is SMC with dihydroartemisinin plus piperaquine (DP). Plasmodium falciparum single nucleotide polymorphisms (SNPs) in P. falciparum crt (pfcrt), pfmdr1, pfdhfr, and pfdhps are associated with decreased response to aminoquinoline and antifolate antimalarials and are selected by use of these drugs. To characterize selection by SMC of key polymorphisms, we assessed 13 SNPs in P. falciparum isolated from children aged 3 to 59 months living in southwestern Burkina Faso and randomized to receive monthly DP or AQ/SP for 3 months in 2009. We compared SNP prevalence before the onset of SMC and 1 month after the third treatment in P. falciparum PCR-positive samples from 120 randomly selected children from each treatment arm and an additional 120 randomly selected children from a control group that did not receive SMC. The prevalence of relevant mutations was increased after SMC with AQ/SP. Significant selection was seen for pfcrt 76T (68.5% to 83.0%, P = 0.04), pfdhfr 59R (54.8% to 83.3%, P = 0.0002), and pfdhfr 108N (55.0% to 87.2%, P = 0.0001), with trends toward selection of pfmdr1 86Y, pfdhfr 51I, and pfdhps 437G. After SMC with DP, only borderline selection of wild-type pfmdr1 D1246 (mutant; 7.7% to 0%, P = 0.05) was seen. In contrast to AQ/SP, SMC with DP did not clearly select for known resistance-mediating polymorphisms. SMC with AQ/SP, but not DP, may hasten the development of resistance to components of this regimen. (This study has been registered at ClinicalTrials.gov under registration no. NCT00941785.).

SUBMITTER: Some AF

PROVIDER: S-EPMC4068591 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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Selection of drug resistance-mediating Plasmodium falciparum genetic polymorphisms by seasonal malaria chemoprevention in Burkina Faso.

Somé Anyirékun Fabrice AF Zongo Issaka I Compaoré Yves-Daniel YD Sakandé Souleymane S Nosten François F Ouédraogo Jean-Bosco JB Rosenthal Philip J PJ

Antimicrobial agents and chemotherapy 20140414 7

Seasonal malaria chemoprevention (SMC), with regular use of amodiaquine plus sulfadoxine-pyrimethamine (AQ/SP) during the transmission season, is now a standard malaria control measure in the Sahel subregion of Africa. Another strategy under study is SMC with dihydroartemisinin plus piperaquine (DP). Plasmodium falciparum single nucleotide polymorphisms (SNPs) in P. falciparum crt (pfcrt), pfmdr1, pfdhfr, and pfdhps are associated with decreased response to aminoquinoline and antifolate antimala ...[more]

PMID: 24733476

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Project description:Burkina Faso implemented the seasonal malaria chemoprevention (SMC) in 2014 in seven pilot health districts, following the new recommendation by the WHO in 2012 for the prevention of the disease in children under five years old, for areas of highly seasonal malaria transmission.The objective of this study was to assess the implementation fidelity of the seasonal malaria chemoprevention strategy in one of the districts, Kaya Health District.We conducted a case study, with a quantitative and qualitative mixed methods. Data were collected after two campaigns of implementation of the intervention, in 2014 and 2015, through a review of specific documents of SMC intervention, and individual interview with key informants (n = 21) involved at various levels in the implementation of the strategy and a household survey with the parents (n = 284) of eligible children for the SMC strategy in 2015 in the Kaya health district. The analysis framework focused on the fidelity of the intervention's content, its coverage, and its schedule, as well as the potential moderating factors, using the model proposed by Hasson, originally from Carroll.All components of the intervention were implemented. Villages and sectors were covered at 100%. In terms of intervention doses received, less than one-third of eligible children (32.3%) received the recommended four doses in 2015. Implementation of the strategy faced some difficulties due to insufficient training of community distributors, inadequate supply of inputs and insufficient financial resources for remuneration, advocacy and supervision, but also because of the contextual constraints due to the rainy season. Moreover, an interaction between the different moderating factors, influencing the degree of implementation of the strategy was noted.Taking into account the moderating factors of the implementation is necessary for achieving the highest possible degree of implementation fidelity and then, reach the expected beneficial effects.

Project description:BACKGROUND:Seasonal malaria chemoprevention (SMC) relies on community health workers to distribute drugs. This study assessed: (1) the capacity of community-based distributors (CBDs) at the start and end of a campaign and from one campaign to another after training or refresher courses before each round; (2) to what extent CBDs' experience over several campaigns contributed to measurable increase in their capacities; and (3) to what extent the training and experience of committed CBDs helped the less productive to catch up. METHODS:A longitudinal analysis was conducted in one Burkina Faso health district during the 2017 and 2018 campaigns. A panel including all CBDs was created. Their capacities were observed after: (1) initial training for the 2017 season; (2) refresher training for that year's fourth round; and (3) initial training for the 2018 season. All were invited to complete a questionnaire at the end of training with 27 multiple-choice questions on their main tasks. Observers noted content coverage and conditions under which training sessions were conducted. RESULTS:The 612 CBDs showed, on average, high understanding of their tasks from the start of the annual campaigns. Tasks related to communicating with parents and reporting were best mastered. Their capacities grew from round to round and campaign to campaign, after most had undergone training and been supervised by head nurses. The greatest progress was in the technical components, considered more complex, which involved selecting eligible children, choosing the correct drug packet, and referring children to health professionals. Retaining CBDs from one round to the next benefited everyone, whatever their starting level. Groups that initially obtained the lowest scores (women, illiterates, youngest/oldest) progressed the most. CONCLUSION:These results confirm the potential of using CBDs under routine programme implementation. Mandating CBDs with targeted tasks is a functional model, as they achieve mastery in this context where investments are made in training and supervision. Losing this specificity by extending CBDs' mandates beyond SMC could have undesirable consequences. The added value of retaining committed CBDs is high. It is suggested that motivation and commitment be considered in recruitment, and that a supportive climate be created to foster retention.

Project description:BackgroundSince 2014, the Burkina Faso government has made Seasonal Malaria Chemoprevention (SMC) a priority in its strategic plan to fight against malaria among children aged from 3 to 59 months. Very few studies have examined the care provided by community health workers in the framework of this strategy. The purpose of this study was to evaluate the level of quality of care provided by the latter.MethodsThis was a mixed study. The quantitative component consisted of a non-participant observation of community health workers during the administration of care. The qualitative component consisted of one-on-one interviews with community health workers, child caregivers and head nurses. Five dimensions (organizational accessibility, interpersonal relationship, technical competence, safety of care and satisfaction of child caregivers) adapted from the Donabedian quality of care model were used to assess the quality level of care. The Corlien et al. Health Systems Research Program Implementation Scale was used to establish quality scores for each of the five dimensions. The study sites were the health centers located in the administrative centers of the 4 communes of the health district of Boulsa. The data were collected during the first cycle of the 2017 SMC campaign.ResultsA total of 14 active pairs (28 CHWs) were observed and 40 in-depth interviews with community health workers, Head nurses in duty and community leaders were conducted. The results show that community health workers worked in pairs. They had all received SMC training and possessed equipment to do their job. The dimensions of organizational accessibility and satisfaction of the caregivers were rated as good. The dimensions of interpersonal relationship and technical competence were judged to be of an acceptable score. Safety of care was judged to be of a low-level score. The overall quality of care was considered acceptable.ConclusionThe results of this study have shown that despite the difficulties faced by community health workers, they manage to deliver acceptable quality of care. Their use would be an asset for SMC in particular and for the health system in general.

Project description:BackgroundIn the context of widespread mosquito resistance to currently available pesticides, novel, precise genetic vector control methods aimed at population suppression or trait replacement are a potentially powerful approach that could complement existing malaria elimination interventions. Such methods require knowledge of vector population composition, dynamics, behaviour and role in transmission. Here were characterized these parameters in three representative villages, Bana, Pala and Souroukoudingan, of the Sudano-Sahelian belt of Burkina Faso, a region where bed net campaigns have recently intensified.MethodsFrom July 2012 to November 2015, adult mosquitoes were collected monthly using pyrethroid spray catches (PSC) and human landing catches (HLC) in each village. Larval habitat prospections assessed breeding sites abundance at each site. Mosquitoes collected by PSC were identified morphologically, and then by molecular technique to species where required, to reveal the seasonal dynamics of local vectors. Monthly entomological inoculation rates (EIR) that reflect malaria transmission dynamics were estimated by combining the HLC data with mosquito sporozoite infection rates (SIR) identified through ELISA-CSP. Finally, population and EIR fluctuations were fit to locally-collected rainfall data to highlight the strong seasonal determinants of mosquito abundance and malaria transmission in this region.ResultsThe principal malaria vectors found were in the Anopheles gambiae complex. Mosquito abundance peaked during the rainy season, but there was variation in vector species composition between villages. Mean survey HLC and SIR were similar across villages and ranged from 18 to 48 mosquitoes/person/night and from 3.1 to 6.6% prevalence. The resulting monthly EIRs were extremely high during the rainy season (0.91-2.35 infectious bites/person/day) but decreased substantially in the dry season (0.03-0.22). Vector and malaria transmission dynamics generally tracked seasonal rainfall variations, and the highest mosquito abundances and EIRs occurred in the rainy season. However, despite low residual mosquito populations, mosquitoes infected with malaria parasites remained present in the dry season.ConclusionThese results highlight the important vector control challenge facing countries with high EIR despite the recent campaigns of bed net distribution. As demonstrated in these villages, malaria transmission is sustained for large parts of the year by a very high vector abundance and high sporozoite prevalence, resulting in seasonal patterns of hyper and hypo-endemicity. There is, therefore, an urgent need for additional vector control tools that can target endo and exophillic mosquito populations.

Project description:BACKGROUND: Malaria during pregnancy remains a serious public health problem. The aim of this study was to determine the prevalence and possible risk factors for malaria in pregnant women attending antenatal clinic at two primary health facilities in Bobo-Dioulasso. METHODS: We conducted a cross sectional study from September to December 2010 in two primary health facilities located in the periurban area of Bobo-Dioulasso. Pregnant women attending antenatal clinic (ANC) were included in the study after signing informed consent. For each participant, the social-demographic profile, malaria and obstetric histories were investigated through a questionnaire. Peripheral blood was collected and thick and thin blood smears were prepared to check Plasmodium falciparum parasitaemia. Hemoglobin concentration was measured. The associations between age, parity, gestational age, schooling, number of ANC visits, use of IPTp-SP, use of insecticide-treated nets (ITN) and anemia with the occurrence of P. falciparum malaria infection during pregnancy were analyzed through logistic regression. RESULTS: During the period of study, 105 (18.1%) out of 579 pregnant women were infected by P. falciparum. The hemoglobin concentration mean was 10.5?±?1.7/dL and was significantly lower in pregnant women with malaria infection (9.8 g/dL ±1.6) than in those who had no malaria infection (10.6 g/dL ±1.7) (P?<?0.001). Multivariate analysis indicated that, education (AOR 1.9, 95% CI?=?[1.2-3.2]), parity [primigravidae (AOR 5.0, 95% CI?=?[2.5-9.8]) and secundigravidae (AOR 2.1, 95% CI?=?[1.2-3.8])], and anaemia (AOR 2.1, 95% CI?=?[1.3-3.5]) were significantly associated with P. falciparum malaria infection. The use of IPTp-SP was not associated with P. falciparum malaria infection. CONCLUSIONS: P. falciparum malaria infection is common in pregnant women attending antenatal clinic and anaemia is an important complication. The results show that the use of IPTp-SP does not reduce the risk of malaria incidence during pregnancy.

Project description:BackgroundSeasonal malaria chemoprevention (SMC) is now widely deployed in the Sahel, including several countries that are major contributors to the global burden of malaria. Consequently, it is important to understand whether SMC continues to provide a high level of protection and how SMC might be improved. SMC was evaluated using data from a large, household-randomised trial in Houndé, Burkina Faso and Bougouni, Mali.Methods and findingsThe parent trial evaluated monthly SMC plus either azithromycin (AZ) or placebo, administered as directly observed therapy 4 times per year between August and November (2014-2016). In July 2014, 19,578 children aged 3-59 months were randomised by household to study group. Children who remained within the age range 3-59 months in August each year, plus children born into study households or who moved into the study area, received study drugs in 2015 and 2016. These analyses focus on the approximately 10,000 children (5,000 per country) under observation each year in the SMC plus placebo group. Despite high coverage and high adherence to SMC, the incidence of hospitalisations or deaths due to malaria and uncomplicated clinical malaria remained high in the study areas (overall incidence rates 12.5 [95% confidence interval (CI): 11.2, 14.1] and 871.1 [95% CI: 852.3, 890.6] cases per 1,000 person-years, respectively) and peaked in July each year, before SMC delivery began in August. The incidence rate ratio comparing SMC within the past 28 days with SMC more than 35 days ago-adjusted for age, country, and household clustering-was 0.13 (95% CI: 0.08, 0.20), P < 0.001 for malaria hospitalisations and deaths from malaria and 0.21 (95% CI 0.20, 0.23), P < 0.001 for uncomplicated malaria, indicating protective efficacy of 87.4% (95% CI: 79.6%, 92.2%) and 78.3% (95% CI: 76.8%, 79.6%), respectively. The prevalence of malaria parasitaemia at weekly surveys during the rainy season and at the end of the transmission season was several times higher in children who missed the SMC course preceding the survey contact, and the smallest prevalence ratio observed was 2.98 (95% CI: 1.95, 4.54), P < 0.001. The frequency of molecular markers of sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) resistance did not increase markedly over the study period either amongst study children or amongst school-age children resident in the study areas. After 3 years of SMC deployment, the day 28 PCR-unadjusted adequate clinical and parasitological response rate of the SP + AQ regimen in children with asymptomatic malaria was 98.3% (95% CI: 88.6%, 99.8%) in Burkina Faso and 96.1% (95% CI: 91.5%, 98.2%) in Mali. Key limitations of this study are the potential overdiagnosis of uncomplicated malaria by rapid diagnostic tests and the potential for residual confounding from factors related to adherence to the monthly SMC schedule.ConclusionDespite strong evidence that SMC is providing a high level of protection, the burden of malaria remains substantial in the 2 study areas. These results emphasise the need for continuing support of SMC programmes. A fifth monthly SMC course is needed to adequately cover the whole transmission season in the study areas and in settings with similar epidemiology.Trial registrationThe AZ-SMC trial in which these data were collected was registered at clinicaltrials.gov: NCT02211729.

Dataset Information

Selection of drug resistance-mediating Plasmodium falciparum genetic polymorphisms by seasonal malaria chemoprevention in Burkina Faso.

Publications

Selection of drug resistance-mediating Plasmodium falciparum genetic polymorphisms by seasonal malaria chemoprevention in Burkina Faso.

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