Résumé
In order to implement a future malaria elimination strategy in French Guiana, a characterization of the infectious reservoir is recommended. We hypothesized that malaria transmission at the border between French Guiana and Brazil could be linked to asymptomatic carriage of P. vivax (Pv) and P. falciparum (Pf). RESULTS A cross-sectional survey associating a community-based approach was conducted between October and December 2017 in a French Guianese village, St Georges de l’Oyapock, bordering Brazil. The prevalence of Plasmodium spp. was determined using Rapid Diagnostic Test (RDT) and a polymerase chain reaction (PCR) for malaria parasite detection. House locations of survey participants were georeferenced. Demographic, medical history, clinical and biological data were analyzed using standard statistical tools. Factors associated with Plasmodium spp. carriage were analyzed using logistic regression and the carriage localization was investigated through spatial cluster analysis. Of the 1,566 study participants included in the study, only 13/1,549 were positive by RDT. Of 1,501 samples analyzed by PCR 90 and 10 were positive for Pv and Pf respectively . The general PCR prevalence was 6.6% IC95% [5.3-7.9], among which, 74% were asymptomatic. In multivariate analysis, age over 15 years, living in a remote neighborhood, a prior history of malaria, anemia and thrombocytopenia were associated with increased odds of Plasmodium spp. carriage. Bed net use was not associated with a lower odd of Plasmodium spp. infection. High-risk clusters of Pv carriage were detected: two hotspots in the most remote neighborhoods outside of the village and two small foci the center of the village. A hotspot of both, Pv and Pf symptomatic carriers, was also detected in the north-western part of the village. CONCLUSIONS The current study confirms a wide-scale presence of asymptomatic Pf and Pv carriers in this area. Although they were more often located in remote areas, their geographic repartitions were spatially heterogeneous and complex. Plasmodium spp. carriage was associated with anemia and thrombocytopenia, which might impact the carrier activities at work or at school depending of their age. These results highlight the importance of defining health strategies based on local situation in each neighborhood and in accordance with human behaviors.