SELECTION OF PFCRT 76T AND PFMDR1 86Y MUTANT PLASMODIUM FALCIPARUM AFTER TREATMENT OF UNCOMPLICATED MALARIA WITH ARTESUNATE-AMODIAQUINE IN REPUBLIC OF GUINEA.

The use of Amodiaquine monotherapy is associated with the selection of molecular markers of Plasmodium falciparum resistance to chloroquine (pfcrt and pfmdr1). The decrease in sensitivity and the emergence of P. falciparum resistant to artemisinin-based combination therapy have been reported. Therefore, it is important to assess the impact of treatment of uncomplicated malaria with Artesunate-Amodiaquine (AS+AQ) on molecular markers of antimalarial resistance. We used standard World Health Organization (WHO) protocols to determine the in vivo efficacy of the combination (AS+AQ). In total, 170 subjects were included in the study. The molecular analysis focused on 168 dried blood spots. The aims were to determine the frequency of pfcrt 76T and pfmdr1 86Y mutations and the rates of reinfection using polymorphism markers msp1, msp2, and microsatellite markers (CA1, Ta87, TA99). Nested-PCR was used, followed in some cases by a restriction digestion. The level of P. falciparum clinical response was 92.9% (156/168) of Adequate Clinical and Parasitological Response (ACPR) before molecular correction and 97.0% (163/168) after molecular correction (P = 0.089). The frequency of mutation point pfcrt 76T was 76.2% (128/168) before treatment and 100% (7/7) after treatment (P = 0.1423). For the pfmdr1 mutation, the frequency was 28% (47/168) before treatment and 60% (6/10) after treatment (P = 0.1124). The rate of pfcrt 76T + pfmdr1 86Y was 22% (37/168) before and 50% (6/12) after treatment (P = 0.1465). Despite the presence of AS in the combination, AS+AQ selects for pfcrt 76T and pfmdr1 86Y mutant P. falciparum in Guinea.

PREVALENCE OF PARASITIC INFECTIONS IN CHILDREN OF BOKE, GUINEA.

Helminthic and intestinal protozoan infections and malaria infections are common in children less than 15 yr old in sub-Saharan Africa, but little is known about these infections in Guinea. The aim of this study was to determine the prevalence of parasitic infections in children aged less than 15 yr and the relationship of these infections with anemia. The cross-sectional study was done in Dabbis sub-prefecture in the Boke region of Guinea from 18 to 26 March 2017. A simple random sampling at the household level was performed, and 1 child under the age of 15 was included per eligible household. A total of 392 children were included in the analysis. Clinical and parasitological information were assessed, including anthropometric measures (weight and height), disease symptoms, hemoglobin level, and malaria parasitemia. Helminthic and protozoan intestinal infections were present in 59.7% of the children surveyed. Malaria infection prevalence was 45.5% when assessed by microscopy and 43.6% when assessed by a rapid diagnostic test. Plasmodium falciparum, accounting for 84.2% of malaria infections, was the main malaria species infection. Gastrointestinal parasites were present in 19.1% of children. The main gastrointestinal parasites present included Entamoeba coli (5.4%) and Giardia intestinalis (5.1%). There was no association between the presence of anemia and the parasitic status of the children. Parasitic screening and mass treatment in this age group, as well as household awareness raising, would reduce cases of parasitic infections in rural Guinea.

An assessment of adult mosquito collection techniques for studying species abundance and diversity in Maferinyah, Guinea.

BACKGROUND: Several mosquito collection methods are routinely used in vector control programmes. However, they target different behaviours causing bias in estimation of species diversity and abundance. Given the paucity of mosquito trap data in West Africa, we compared the performance of five trap-lure combinations and Human Landing Catches (HLCs) in Guinea. METHODS: CDC light traps (LT), BG sentinel 2 traps (BG2T), gravid traps (GT) and Stealth traps (ST) were compared in a 5 × 5 Latin Square design in three villages in Guinea between June and July 2018. The ST, a portable trap which performs similarly to a LT but incorporates LEDs and incandescent light, was included since it has not been widely tested. BG2T were used with BG and MB5 lures instead of CO2 to test the efficacy of these attractants. HLCs were performed for 5 nights, but not as part of the Latin Square. A Generalised Linear Mixed Model was applied to compare the effect of the traps, sites and collection times on mosquito abundance. Species identification was confirmed using PCR-based analysis and Sanger sequencing. RESULTS: A total of 10,610 mosquitoes were captured across five traps. ST collected significantly more mosquitoes (7096) than the rest of the traps, but resulted in a higher number of damaged specimens. ST and BG2T collected the highest numbers of Anopheles gambiae (s.l.) and Aedes aegypti mosquitoes, respectively. HLCs captured predominantly An. coluzzii (41%) and hybrids of An. gambiae and An. coluzzii (36%) in contrast to the five traps, which captured predominantly An. melas (83%). The rural site (Senguelen) presented the highest abundance of mosquitoes and overall diversity in comparison with Fandie (semi-rural) and Maferinyah Centre I (semi-urban). Our results confirm the presence of four species for the first time in Guinea. CONCLUSIONS: ST collected the highest number of mosquitoes suggesting this trap may play an important role for mosquito surveillance in Guinea and similar sites in West Africa. We recommend the incorporation of molecular tools in entomological studies since they have helped to identify 25 mosquito species in this area.