Submicroscopic infection from uncomplicated Plasmodium falciparum malaria of Franceville, southeastern Gabon

Background: In Gabon malaria is hyperendemic with perennial transmission. PCR provides a powerful tool to detect submicroscopic infection (SMI) allowing improving disease control strategies with regard to its eradication policy. The objective was to determine the prevalence of both patent and SMI of P. falciparum in symptomatic patients. Materials and methods: Two cross-sectional studies were carried out in two local hospitals of Franceville, from May to July 2011 and from February to May 2012. A total of 595 symptomatic patients were enrolled, 250 in the first and 345 in the second study. A clinical examination and parasitological diagnosis by microscopy and PCR were carried out in all patients. Results: Of the 250 patients enrolled in the first study, the prevalence of P. falciparum was 24.00% (60/250) and 9.60% (24/250) for patent and SMI respectively with an overall prevalence of 33.60% (84/250). In the second study, a prevalence of 21.45% (74/345) for patent infections and 9.57% (33/345) for SMI was obtained with a global prevalence of 31.01% (107/345). Overall, 66.40% and 69.00% of patients were free of P. falciparum infection respectively for study 1 and 2. The SMI occurs in symptomatic patients of Franceville in an average of 9.00% of cases with a relative high prevalence at the beginning and the end of the rainy seasons. Conclusion: These results should be used not only to develop the management of the disease but also to improve control strategies such as intermittent preventive treatment across the target population.