title: Marked Rise in the Prevalence of Asymptomatic Plasmodium falciparum Infection in Rural Gabon.
abstract: Control strategies implemented a decade ago led to a marked reduction in the prevalence of malaria in many countries. In Dienga, southeastern Gabon, the prevalence of microscopic P. falciparum infection was 7% in 2003, close to the pre-elimination threshold of 5%. The aim of this work was to determine the prevalence of P. falciparum infection in the same community a decade later. A cohort of 370 individuals aged from 3 to 85 years living in Dienga was investigated for P. falciparum infection; during six passages (P) in 15-month period. Demographic data were collected, along with behaviors and attitudes towards malaria. Plasmodium infection was diagnosed by microscopy (ME), followed by PCR to detect submicroscopic infection. The prevalence of P. falciparum infection in P1, P2, P3, P4, P5 and P6 was respectively 43.5% (25.1% ME+, 18.4% PCR+); 40.9% (27.0% ME+, 13.9% PCR+), 52.7% (26.1% ME+, 26.6% PCR+); 34.1% (14.1% ME+, 20% PCR+), 57.7% (25.4.% ME+, 32.3% PCR+); and 46.2% (21.4% ME+, 24.8% PCR+) with an overall average of 45.9% (95%CI [37.0-54.7], 23.2% ME+ and 22.7% PCR+). P4 and P5 prevalences were statically different throughout the six passages. Microscopic prevalence was significantly higher than that observed ten years ago (23% [n = 370] vs 7% [n = 323], p < 0.001). Asymptomatic infections were the most frequent (96%). Gametocytes were detected in levels ranging from 5.9% to 13.9%. Insecticide-treated nets, indoor residual insecticides, and self-medication were used by respectively 33.2% (95%CI [29.0-37.4]), 17.7% (95%CI [15.5-19.9]) and 12.1% (95%CI [10.6-13.6]) of the study population. A near-threefold increase in P. falciparum infection has been observed in a rural area of southeastern Gabon during a 10-year period. Most infections were asymptomatic, but these subjects likely represent a parasite reservoir. These findings call for urgent reinforcement of preventive measures.
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.|Ecole Doctorale Régionale (EDR) en Infectiologie Tropicale, BP: 876 Franceville, Gabon.
authors.forename: Irène
authors.initials: I
authors.lastname: Pegha Moukandja
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.|Ecole Doctorale Régionale (EDR) en Infectiologie Tropicale, BP: 876 Franceville, Gabon.
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Biteghe Bi Essone
authors.affiliation: Département d'Epidémiologie et des Affections Parasitaires, MRTC, Faculté de Médecine et d'Odontostomatologie, Université de Bamako, BP 1805 Bamako, Mali.
authors.forename: Issaka
authors.initials: I
authors.lastname: Sagara
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.
authors.forename: Roland Fabrice
authors.initials: RF
authors.lastname: Kassa Kassa
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.
authors.forename: Julien
authors.initials: J
authors.lastname: Ondzaga
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.|Ecole Doctorale Régionale (EDR) en Infectiologie Tropicale, BP: 876 Franceville, Gabon.|Département de Parasitologie-Mycologie Médecine Tropicale, Faculté de Médecine, Université des Sciences de la Santé, B.P. 4009 Libreville, Gabon.
authors.forename: Jean-Bernard
authors.initials: JB
authors.lastname: Lékana Douki
authors.affiliation: Département de Parasitologie-Mycologie Médecine Tropicale, Faculté de Médecine, Université des Sciences de la Santé, B.P. 4009 Libreville, Gabon.
authors.forename: Marielle
authors.initials: M
authors.lastname: Bouyou Akotet
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.
authors.forename: Dieudonne
authors.initials: D
authors.lastname: Nkoghe Mba
authors.affiliation: Centre International de Recherches Médicales de Franceville (CIRMF) B.P. 769 Franceville, Gabon.
authors.forename: Fousseyni S
authors.initials: FS
authors.lastname: Touré Ndouo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000097:blood; D005260:Female; D005681:Gabon / Q000453:epidemiology; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood* / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D012424:Rural Population
chemical_list: D016054:DNA, Protozoan