Abstract
Plasmodium infections in endemic areas are often asymptomatic, can be caused by different species and contribute significantly to transmission. We performed a cross-sectional study in February/March 2016 including 840 individuals ≥ 1 year living in rural Gabon (Ngounié and Moyen-Ogooué). Plasmodium parasitemia was measured by high-sensitive, real-time quantitative PCR. In a randomly chosen subset of P. falciparum infections, gametocyte carriage and prevalence of chloroquine-resistant genotypes were analysed. 618/834 (74%) individuals were positive for Plasmodium 18S-rRNA gene amplification, of these 553 (66.3%) carried P. falciparum, 193 (23%) P. malariae, 74 (8.9%) P. ovale curtisi and 38 (4.6%) P.ovale wallikeri. Non-falciparum infections mostly presented as mixed infections. P. malariae monoinfected individuals were significantly older (median age: 60 years) than coinfected (20 years) or P. falciparum monoinfected individuals (23 years). P. falciparum gametocyte carriage was confirmed in 109/223 (48.9%) individuals, prevalence of chloroquine-resistant genotypes was high (298/336, 89%), including four infections with a new SVMNK genotype. In rural Gabon, Plasmodium infections with all endemic species are frequent, emphasizing that malaria control efforts shall cover asymptomatic infections also including non-falciparum infections when aiming for eradication.
Highlights
Due to huge efforts in elimination and eradication of malaria the numbers of malaria cases and deaths reduced substantially according to WHO in recent years[1]
We included 840 individuals and obtained blood of 834 persons, description of the study population is given in Fig. 1. 311/834 (37%) individuals were positive for Plasmodium parasites by Giemsa stained thick blood smear, 72 (8.6%) of them were considered as being mixed or non-falciparum infections
Body temperature was recorded for 771 individuals, mean temperature was 37.1 °C; 24 individuals presented with a body temperature ≥ 38 °C, 14 of those 24 had a parasitemia that could be detected by microscopy
Summary
We included 840 individuals and obtained blood of 834 persons, description of the study population is given in Fig. 1. 311/834 (37%) individuals were positive for Plasmodium parasites by Giemsa stained thick blood smear, 72 (8.6%) of them were considered as being mixed or non-falciparum infections. The parasitemia of P. malariae positive individuals decreased with age (p < 0.0001, Fig. 3) These data should not be over-interpreted as species-specific PCR was done after preamplification. P. malariae was the most abundant non-falciparum parasite, 90.6% (175/193) infections presented as coinfections with another species. Age group (years) 1–5 6–10 11–15 16–20 21–25 26–30 31–40 41–50 51–60 61–70 71–80 81–96 Sum. older than for the individuals having a mixed infection of P. malariae with P. falciparum (n = 174, median age = 20 years, IQR: 11.75–49 years; p < 0.0001, U test, see Fig. 4). For the other non-falciparum infections sample size was small, for P. ovale curtisi monoinfected individuals (n = 7) the median age was 42 years (IQR: 10–60 years) versus 14 years (IQR: 9–46 years) in individuals having a mixed infection of P. ovale curtisi with P. falciparum (n = 43). The prevalence of CQ resistance remained at 89% sixteen years after the withdrawal of the drug from national treatment guidelines
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
