Malaria Prevalence in Asymptomatic and Symptomatic Children Living in Rural, Semi-Urban and Urban Areas in Eastern Gabon.

Abstract

Background Malaria remains a major public health issue in the world despite a decline in the disease burden. However, though symptomatic malaria is diagnosed and treated, asymptomatic infections remain poorly known and support transmission. This study assessed the prevalence of symptomatic and asymptomatic plasmodial infections in three areas in Gabon to monitor and evaluate the impact of malaria. Methods A cross-sectional study was conducted at the Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF). Febrile children and without fever, aged 6 months to 15 years from three localities (Franceville, Makokou, Lastoursville) in south-eastern Gabon were included in this study. The Plasmodium Spp infection was determined by microscopy and/or rapid diagnostic tests (RDT) followed by PCR according to the Snounou method. The data were recorded in Excel, and the statistical analyzes were performed using the software R version R 64x 3.5.0. Results Two thousand three hundred and eighty-one (2381) children were screened and included in this analysis. The mean age was significantly higher in asymptomatic children compared to symptomatic children. Hematological parameters varied significantly according to regions and clinical signs. The overall prevalence of Plasmodium infection was 40% (952/2381). In the urban area (Franceville) the prevalence of plasmodial infection was not significantly different between symptomatic and asymptomatic children. In contrast, a high prevalence of symptomatic plasmodial infection was found in infected children in rural and semi-rural areas. Among the three plasmodial species (Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale) identified, Plasmodium falciparum was the most widespread, and its prevalence was not significantly different between symptomatic and asymptomatic children in the three localities. In rural and semi-rural areas, a higher or lower prevalence of Plasmodium malariae was demonstrated in asymptomatic children. Conclusion This study showed that the prevalence of plasmodial infection varied according to the regions and clinical signs. The main species was Plasmodium falciparum, but in asymptomatic children the prevalence of Plasmodium malariae was high in rural areas. To help fight malaria more effectively asymptomatic infections should be taken into account and treated.