Comparaison de l’efficacité thérapeutique et de la tolérance du praziquantel administré en prise unique à la dose de 40 versus 60 mg/kg pour le traitement de la bilharziose urinaire en Mauritanie

During the last twenty years, praziquantel (PZQ) was the drug of choice for the treatment of schistosomiasis in the majority of national programs. However, a lower rate of cure had been significantly noted on the left bank of the Senegal River. To explain this unusual rate of cure, the assumption of a possible resistance to the drug as well as under-dosing was considered. With an aim of testing this hypothesis of underdosing, we compared the amount of a single dose of 60 mg/kg of PZQ versus the standardized dose of 40 mg/kg used in curing urinary schistosomiasis in Mauritania. One hundred and fifty-one children aged from 10 to 19 years, including 77 in the group of 60 mg/kg and 74 in the group of 40 mg/ kg, were included in the study. The rates of cure were respectively 64.8% for 60 mg/kg and 67.5% for 40 mg/kg three weeks after the administration of the treatment without statistically significant difference. For the majority of the patients, the drug was well tolerated and no serious adverse events were noted; however, clinical signs in the form of abdominal pain associated or not with diarrhea and vomiting were noted. Praziquantel remains an effective and well-tolerated drug: the amount of 40 mg/kg of body weight can still be maintained for the treatment of schistosomiasis in Mauritania.     

Do antibody responses to malaria vaccine candidates influenced by the level of malaria transmission protect from malaria?

Objectives To examine whether the humoural response to malaria vaccine candidate antigens, Plasmodium falciparum [circumsporozoite repetitive sequence (NANP)₅ GLURP fragments (R0 and R2) and MSP3] varies with the level of malaria transmission and to determine whether the antibodies (IgG) present at the beginning of the malaria transmission season protect against clinical malaria. Methods Cross‐sectional surveys were conducted to measure antibody response before, at the peak and at the end of the transmission season in children aged 6 months to 10 years in two villages with different levels of malaria transmission. A cohort study was performed to estimate the incidence of clinical malaria. Results Antibodies to these antigens showed different seasonal patterns. IgG concentrations to any of the four antigens were higher in the village with high entomological inoculation rate. Multivariate analysis of combined data from the two villages indicated that children who were classified as responders to the selected antigens were at lower risk of clinical malaria than children classified as non‐responders [(NANP)₅ (incidence rate ratio (IRR) = 0.65, 95% CI: 0.46–0.92; P = 0.016), R0 (IRR = 0.69, 95% CI: 0.48–0.97; P = 0.032), R2 (IRR = 0.73, 95% CI: 0.50–1.06; P = 0.09), MSP3 (IRR = 0.52, 95% CI: 0.32–0.85; P = 0.009)]. Fitting a model with all four antibody responses showed that MSP3 looked the best malaria vaccine candidate (IRR = 0.63; 95% CI: 0.38–1.05; P = 0.08). Conclusion Antibody levels to the four antigens are affected by the intensity of malaria transmission and associated with protection against clinical malaria. It is worthwhile investing in the development of these antigens as potential malaria vaccine candidates.