Données préliminaires sur l’écologie des chauves-souris frugivores de la commune du Plateau (Abidjan, Côte d’Ivoire)

La communauté de chauves-souris frugivores de la Commune du Plateau à Abidjan a été étudiée d’août 2005 à juillet 2006. Cette étude a été réalisée en procédant à des observations directes et des comptages aux pieds d’arbres en vue de connaître les espèces présentes, leur effectif et d’établir leur préférence d’habitat. Les résultats indiquent que cette commune héberge deux espèces de Mégachiroptères, la chauve-souris paillée, Eidolon helvum (Kerr, 1792) représentée par une très forte colonie et la chauve-souris à tête de marteau, Hypsignathus monstrosus H. Allen, 1861, observée pour la première fois et représentée par quelques individus. L’effectif de la population de chauves-souris paillées est en moyenne de 185 049 ± 1291,5 individus. Les effectifs ont varié selon le site et la saison. Les chauves-souris paillées ont une préférence d’habitat marquée pour les sites dortoirs à Mangifera indica L. (Anacardiaceae).Mots clés : Chauves-souris frugivores, inventaire, habitat, milieu urbain

Small-scale field evaluation of PermaNet® Dual (a long-lasting net coated with a mixture of chlorfenapyr and deltamethrin) against pyrethroid-resistant Anopheles gambiae mosquitoes from Tiassalé, Côte d'Ivoire

BACKGROUND: Due to the rapid expansion of pyrethroid-resistance in malaria vectors in Africa, Global Plan for Insecticide Resistance Management (GPIRM) has recommended the development of long-lasting insecticidal nets (LLINs), containing insecticide mixtures of active ingredients with different modes of action to mitigate resistance and improve LLIN efficacy. This good laboratory practice (GLP) study evaluated the efficacy of the chlorfenapyr and deltamethrin-coated PermaNet((R)) Dual, in comparison with the deltamethrin and synergist piperonyl butoxide (PBO)-treated PermaNet((R)) 3.0 and the deltamethrin-coated PermaNet((R)) 2.0, against wild free-flying pyrethroid-resistant Anopheles gambiae sensu lato (s.l.), in experimental huts in Tiassale, Cote d'Ivoire (West Africa). METHODS: PermaNet((R)) Dual, PermaNet((R)) 3.0 and PermaNet((R)) 2.0, unwashed and washed (20 washes), were tested against free-flying pyrethroid-resistant An. gambiae s.l. in the experimental huts in Tiassale, Cote d'Ivoire from March to August 2020. Complementary laboratory cone bioassays (daytime and 3-min exposure) and tunnel tests (nightly and 15-h exposure) were performed against pyrethroid-susceptible An. gambiae sensu stricto (s.s.) (Kisumu strain) and pyrethroid-resistant An. gambiae s.l. (Tiassale strain). RESULTS: PermaNet((R)) Dual demonstrated significantly improved efficacy, compared to PermaNet((R)) 3.0 and PermaNet((R)) 2.0, against the pyrethroid-resistant An. gambiae s.l. Indeed, the experimental hut trial data showed that the mortality and blood-feeding inhibition in the wild pyrethroid-resistant An. gambiae s.l. were overall significantly higher with PermaNet((R)) Dual compared with PermaNet((R)) 3.0 and PermaNet((R)) 2.0, for both unwashed and washed samples. The mortality with unwashed and washed samples were 93.6 +/- 0.2% and 83.2 +/- 0.9% for PermaNet((R)) Dual, 37.5 +/- 2.9% and 14.4 +/- 3.9% for PermaNet((R)) 3.0, and 7.4 +/- 5.1% and 11.7 +/- 3.4% for PermaNet((R)) 2.0, respectively. Moreover, unwashed and washed samples produced the respective percentage blood-feeding inhibition of 41.4 +/- 6.9% and 43.7 +/- 4.8% with PermaNet((R)) Dual, 51.0 +/- 5.7% and 9.8 +/- 3.6% with PermaNet((R)) 3.0, and 12.8 +/- 4.3% and - 13.0 +/- 3.6% with PermaNet((R)) 2.0. Overall, PermaNet((R)) Dual also induced higher or similar deterrence, exophily and personal protection when compared with the standard PermaNet((R)) 3.0 and PermaNet((R)) 2.0 reference nets, with both unwashed and washed net samples. In contrast to cone bioassays, tunnel tests predicted the efficacy of PermaNet((R)) Dual seen in the current experimental hut trial. CONCLUSION: The deltamethrin-chlorfenapyr-coated PermaNet((R)) Dual induced a high efficacy and performed better than the deltamethrin-PBO PermaNet((R)) 3.0 and the deltamethrin-only PermaNet((R)) 2.0, testing both unwashed and 20 times washed samples against the pyrethroid-susceptible and resistant strains of An. gambiae s.l. The inclusion of chlorfenapyr with deltamethrin in PermaNet((R)) Dual net greatly improved protection and control of pyrethroid-resistant An. gambiae populations. PermaNet((R)) Dual thus represents a promising tool, with a high potential to reduce malaria transmission and provide community protection in areas compromised by mosquito vector resistance to pyrethroids

Prevalence of Schistosoma mono- and co-infections with multiple common parasites and associated risk factors and morbidity profile among adults in the Taabo health and demographic surveillance system, South-Central Côte d'Ivoire

BACKGROUND: Schistosomiasis remains an important public health problem, also among adults, and infected individuals not treated serve as a reservoir for continued transmission. Despite this fact, evidence on the epidemiology of schistosomiasis in adults in Cote d'Ivoire is scanty. This study aimed to determine the prevalence and risk factors of Schistosoma infection and co-infection with other helminth species and Plasmodium among adults in the Taabo region in the south-central part of Cote d'Ivoire. METHODS: A cross-sectional survey was carried out in April and May 2017 in the frame of the "Cote d'Ivoire Dual Burden of Disease Study" (CoDuBu). A total of 901 randomly selected individuals, aged 18-90 years, provided blood, stool and urine samples for the diagnosis of malaria and helminth infections. Stool samples were subjected to the Kato-Katz technique for detection of Schistosoma mansoni and soil-transmitted helminth eggs, while urine samples were examined for eggs of Schistosoma haematobium and circulating cathodic antigen of S. mansoni. Risk factors and morbidity profiles were assessed using health examination and questionnaires. Multinomial logistic regressions were employed to identify risk factors and morbidity patterns associated with S. mansoni mono- and co-infections. RESULTS: The prevalence of S. mansoni and S. haematobium was 23.2% and 1.0%, respectively. Most S. mansoni were mono-infections (81.3%). Independent determinants of S. mansoni infection were young age, low socioeconomic status (mono- and co-infection) and poor hygiene practices (co-infection) (P < 0.05). S. mansoni infection was independently associated with higher pain and symptom scores (mono-infection), poor self-rated health and low healthcare use (co-infection) (P < 0.05). CONCLUSIONS: This study showed that adults represent a substantial reservoir of S. mansoni. To sustain schistosomiasis control and improve people's wellbeing, it is important to expand preventive chemotherapy from school-aged children to adults, coupled with hygiene and health education