Impact de la dynamique de peuplement sur la distribution des glossines et des trypanosomoses dans la boucle du Mouhoun (Burkina Faso)

In Burkina Faso, the Mouhoun river basin (formerly 'Black Volta") constitutes a historical focus of Human (HAT) and Animal (AAT) African Tryponosomoses, both transmitted by tsetse flies. Nowadays, HAT seems to have disappeared from this area, while AAT still causes severe economic losses. In order to explain these different epidemiological situations, we undertook a geographical study based on the analysis of aerial pictures between 1952 and 2007, and field surveys to collect medical, entomological, and veterinary data on trypanosomoses. Our results suggest that in this area, landscapes have been dramatically modified as a consequence of population growth, and in turn have had an impact on the number and distribution of tsetse flies. Combined with the historical medical action on HAT which probably led to the disappearance of T. b. gambiense, this environmental degradation and the development of hydrological structures provide explanations for the local disappearance of HAT, and for the maintenance of AAT. It appears necessary to extrapolate these studies to other areas in order to identify the factors explaining the presence/absence of trypanosomoses in the context of human population growth and climatic changes, in orde

Artemether-lumefantrine versus amodiaquine plus sulfadoxine-pyrimethamine for uncomplicated falciparum malaria in Burkina Faso: a randomised non-inferiority trial.

BACKGROUND: Artemisinin-based combination regimens are widely advocated for malarial treatment, but other effective regimens might be cheaper and more readily available. Our aim was to compare the risk of recurrent parasitaemia in patients given artemether-lumefantrine with that in those given amodiaquine plus sulfadoxine-pyrimethamine for uncomplicated malaria. METHODS: We enrolled 521 patients aged 6 months or older with uncomplicated falciparum malaria in Bobo-Dioulasso, Burkina Faso. Patients were randomly assigned to receive standard doses of either artemether-lumefantrine (261) or amodiaquine plus sulfadoxine-pyrimethamine (260) for 3 days. Primary endpoints were the risks of treatment failure within 28 days, either unadjusted or adjusted by genotyping to distinguish recrudescence from new infection. The study is registered at controlled-trials.gov with the identifier ISRCTN54261005. FINDINGS: Of enrolled patients, 478 (92%) completed the 28-day study. The risk of recurrent symptomatic malaria was lowest in the group given amodiaquine plus sulfadoxine-pyrimethamine (1.7%vs 10.2%; risk difference 8.5%; 95% CI 4.3-12.6; p=0.0001); as was the risk of recurrent parasitaemia (4.7%vs 15.1%; 10.4%; 5.1-15.6; p=0.0002). Nearly all recurrences were due to new infections. Recrudescences were four late treatment failures with artemether-lumefantrine and one early treatment failure with amodiaquine plus sulfadoxine-pyrimethamine. Both regimens were safe and well tolerated, with pruritus more common with amodiaquine plus sulfadoxine-pyrimethamine than with artemether-lumefantrine. Each regimen selected for new isolates with mutations that have been associated with decreased drug susceptibility. INTERPRETATION: Amodiaquine plus sulfadoxine-pyrimethamine was more effective than was artemether-lumefantrine for the treatment of uncomplicated malaria. For regions of Africa where amodiaquine plus sulfadoxine-pyrimethamine continues to be effective, this less expensive and more available regimen should be considered as an alternative to blanket recommendations for artemisinin-based combination treatment for malaria

Epidemiology of sleeping sickness in Boffa (Guinea) : where are the trypanosomes ?

Human African Trypanosomiasis (HAT) in West Africa is a lethal, neglected disease caused by Trypanosoma brucei gambiense transmitted by the tsetse Glossina palpalis gambiensis. Although the littoral part of Guinea with its typical mangrove habitat is the most prevalent area in West Africa, very few data are available on the epidemiology of the disease in such biotopes. As part of a HAT elimination project in Guinea, we carried a cross-sectional study of the distribution and abundance of people, livestock, tsetse and trypanosomes in the focus of Boffa. An exhaustive census of the human population was done, together with spatial mapping of the area. Entomological data were collected, a human medical survey was organized together with a survey in domestic animals. In total, 45 HAT cases were detected out of 14445 people who attended the survey, these latter representing 50.9% of the total population. Potential additional carriers of T. b. gambiense were also identified by the trypanolysis test (14 human subjects and two domestic animals). No trypanosome pathogenic to animals were found, neither in the 874 tsetse dissected nor in the 300 domestic animals sampled. High densities of tsetse were found in places frequented by humans, such as pirogue jetties, narrow mangrove channels and watering points. The prevalence of T. b. gambiense in humans, combined to low attendance of the population at risk to medical surveys, and to an additional proportion of human and animal carriers of T. b. gambiense who are not treated, highlights the limits of strategies targeting HAT patients only. In order to stop T. b. gambiense transmission, vector control should be added to the current strategy of case detection and treatment. Such an integrated strategy will combine medical surveillance to find and treat cases, and vector control activities to protect people from the infective bites of tsetse

HRP2 and pLDH-Based Rapid Diagnostic Tests, Expert Microscopy, and PCR for Detection of Malaria Infection during Pregnancy and at Delivery in Areas of Varied Transmission: A Prospective Cohort Study in Burkina Faso and Uganda.

BACKGROUND: Intermittent screening and treatment (IST) of malaria during pregnancy has been proposed as an alternative to intermittent preventive treatment in pregnancy (IPTp), where IPTp is failing due to drug resistance. However, the antenatal parasitaemias are frequently very low, and the most appropriate screening test for IST has not been defined. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a multi-center prospective study of 990 HIV-uninfected women attending ANC in two different malaria transmission settings at Tororo District Hospital, eastern Uganda and Colsama Health Center in western Burkina Faso. Women were enrolled in the study in the second or third trimester of pregnancy and followed to delivery, generating 2,597 blood samples for analysis. Screening tests included rapid diagnostic tests (RDTs) targeting histidine-rich protein 2 (HRP2) and parasite lactate dehydrogenase (pLDH) and microscopy, compared to nPCR as a reference standard. At enrolment, the proportion of pregnant women who were positive for P. falciparum by HRP2/pan pLDH RDT, Pf pLDH/pan pLDH RDT, microscopy and PCR was 38%, 29%, 36% and 44% in Uganda and 21%, 16%, 15% and 35% in Burkina Faso, respectively. All test positivity rates declined during follow-up. In comparison to PCR, the sensitivity of the HRP2/pan pLDH RDT, Pf pLDH/pan pLDH RDT and microscopy was 75.7%, 60.1% and 69.7% in Uganda, 55.8%, 42.6% and 55.8% in Burkina Faso respectively for all antenatal visits. Specificity was greater than 96% for all three tests. Comparison of accuracy using generalized estimating equation revealed that the HRP2- detecting RDT was the most accurate test in both settings. CONCLUSIONS/SIGNIFICANCE: The study suggests that HRP2-based RDTs are the most appropriate point-of-care test currently available for use during pregnancy especially for symptomatic women, but will still miss some PCR-positive women. The clinical significance of these very low density infections needs to be better defined

Major reduction of malaria morbidity with combined vitamin A and zinc supplementation in young children in Burkina Faso: a randomized double blind trial

BACKGROUND: Vitamin A and zinc are crucial for normal immune function, and may play a synergistic role for reducing the risk of infection including malaria caused by Plasmodium falciparum. METHODS: A randomized, double-blind, placebo-controlled trial of a single dose of 200 000 IU of vitamin A with daily zinc supplementation was done in children of Sourkoudougou village, Burkina Faso. Children aged from 6 to 72 months were randomized to receive a single dose of 200 000 IU of vitamin A plus 10 mg elemental zinc, six days a week (n = 74) or placebo (n = 74) for a period of six months. Cross-sectional surveys were conducted at the beginning and the end of the study, and children were evaluated daily for fever. Microscopic examination of blood smear was done in the case of fever (temperature > or =37.5 degrees C) for malaria parasite detection. RESULTS: At the end of the study we observed a significant decrease in the prevalence malaria in the supplemented group (34%) compared to the placebo group (3.5%) (p < 0.001). Malaria episodes were lower in the supplemented group (p = 0.029), with a 30.2% reduction of malaria cases (p = 0.025). Time to first malaria episode was longer in the supplemented group (p = 0.015). The supplemented group also had 22% fewer fever episodes than the placebo group (p = 0.030). CONCLUSION: These results suggest that combined vitamin A plus zinc supplementation reduces the risk of fever and clinical malaria episodes among children, and thus may play a key role in malaria control strategies for children in Africa

Randomized comparison of amodiaquine plus sulfadoxine-pyrimethamine, artemether-lumefantrine, and dihydroartemisinin-piperaquine for the treatment of uncomplicated Plasmodium falciparum malaria in Burkina Faso.

BACKGROUND: Combination antimalarial therapy is advocated to improve treatment efficacy and limit selection of drug-resistant parasites. We compared the efficacies of 3 combination regimens in Bobo-Dioulasso, Burkina Faso: amodiaquine plus sulfadoxine-pyrimethamine, which was recently shown to be highly efficacious at this site; artemether-lumefantrine, the new national first-line antimalarial regimen; and dihydroartemisinin-piperaquine (DP), a newer regimen. METHODS: We enrolled 559 patients >or=6 months of age with uncomplicated Plasmodium falciparum malaria and randomized them to the 3 regimens. We analyzed the risk of recurrent parasitemia by day 28 and day 42, both unadjusted and adjusted by PCR methods to distinguish recrudescence and new infection. RESULTS: Complete data were available for 517 (92.5%) of the enrolled subjects. Early treatment failures occurred in 5 patients treated with amodiaquine plus sulfadoxine-pyrimethamine and in 2 patients each treated with the other regimens. The day 28 risk of recurrent parasitemia, unadjusted by genotyping, was significantly higher for patients receiving artemether-lumefantrine than for patients receiving amodiaquine plus sulfadoxine-pyrimethamine (20.1% vs. 6.2%; risk difference, 13.8%; 95% confidence interval, 7.0%-20.7%) or dihydroartemisinin-piperaquine (20.1% vs. 2.2%; risk difference, 17.9%; 95% confidence interval, 11.6%-24.1%). Similar differences were seen for children <5 years of age (54% of the study population) and when outcomes were extended to 42 days. Significant differences were not seen between outcomes for patients receiving amodiaquine plus sulfadoxine-pyrimethamine and outcomes for those receiving dihydroartemisinin-piperaquine. Recrudescences were uncommon (occurring in <5% of patients) in all treatment groups. No serious adverse events were noted. CONCLUSIONS: All regimens were highly efficacious in clearing infection, but considering the risks of recurrent malaria after therapy, the amodiaquine plus sulfadoxine-pyrimethamine and dihydroartemisinin-piperaquine regimens were more efficacious than the artemether-lumefantrine regimen (the new national regimen in Burkina Faso) for the treatment of uncomplicated P. falciparum malaria

Caregiver Recognition of Childhood Diarrhea, Care Seeking Behaviors and Home Treatment Practices in Rural Burkina Faso: A Cross-Sectional Survey

Introduction: To design effective national diarrhea control programs, including oral rehydration solution (ORS) and therapeutic zinc supplementation, information is needed on local perceptions of illness, external care seeking behaviors, and home treatment practices. Methods: A cross-sectional, community-based household survey was conducted in the Orodara Health District, Burkina Faso. Caregivers of 10,490 children,27 months were interviewed to assess child diarrhea prevalence and related car

A Randomized Trial to Assess the Impact of a Package of Diagnostic Tools and Diagnostic Algorithm on Antibiotic Prescriptions for the Management of Febrile Illnesses Among Children and Adolescents in Primary Health Facilities in Burkina Faso.

BACKGROUND: Low- and middle-income countries face significant challenges in differentiating bacterial from viral causes of febrile illnesses, leading to inappropriate use of antibiotics. This trial aimed to evaluate the impact of an intervention package comprising diagnostic tests, a diagnostic algorithm, and a training-and-communication package on antibiotic prescriptions and clinical outcomes. METHODS: Patients aged 6 months to 18 years with fever or history of fever within the past 7 days with no focus, or a suspected respiratory tract infection, arriving at 2 health facilities were randomized to either the intervention package or standard practice. The primary outcomes were the proportions of patients who recovered at day 7 (D7) and patients prescribed antibiotics at day 0. RESULTS: Of 1718 patients randomized, 1681 (97.8%; intervention: 844; control: 837) completed follow-up: 99.5% recovered at D7 in the intervention arm versus 100% in standard practice (P = .135). Antibiotics were prescribed to 40.6% of patients in the intervention group versus 57.5% in the control arm (risk ratio: 29.3%; 95% CI: 21.8-36.0%; risk difference [RD]: -16.8%; 95% CI: -21.7% to -12.0%; P < .001), which translates to 1 additional antibiotic prescription saved every 6 (95% CI: 5-8) consultations. This reduction was significant regardless of test results for malaria, but was greater in patients without malaria (RD: -46.0%; -54.7% to -37.4%; P < .001), those with a respiratory diagnosis (RD: -38.2%; -43.8% to -32.6%; P < .001), and in children 6-59 months old (RD: -20.4%; -26.0% to -14.9%; P < .001). Except for the period July-September, the reduction was consistent across the other quarters (P < .001). CONCLUSIONS: The implementation of the package can reduce inappropriate antibiotic prescription without compromising clinical outcomes. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov; NCT04081051