Exploring the heterogeneity of human exposure to malaria vectors in an urban setting, Bouake, Cote d'Ivoire, using an immuno-epidemiological biomarker

2019

Article référencé dans le Web of Science WOS:000460956200001

Traore D. F., Sagna A. B., Adja A. M., Zoh D. D., Adou K. A., Lingue K. N., Coulibaly I., Tchiekoi N. B., Assi S. B., Poinsignon Anne, Dagnogo M., Remoué Franck

Malaria Journal, 2019, 18, p. art. 68 [10 p.] ISSN 1475-2875

BackgroundIn some African cities, urban malaria is a threat to the health and welfare of city dwellers. To improve the control of the disease, it is critical to identify neighbourhoods where the risk of malaria transmission is the highest. This study aims to evaluate the heterogeneity of malaria transmission risk in one city (Bouake) in a West African country (Cote d'Ivoire) that presents several levels of urbanization.MethodsTwo cross-sectional studies were conducted in three neighbourhoods (Dar-es-Salam, Kennedy and N'gattakro) in Bouake during both the rainy and dry seasons. Data on insecticide-treated net (ITN) use and blood samples were collected from children aged between 6months and 15years to determine the parasite density and the prevalence of Plasmodium falciparum and the level of IgG against the Anopheles gSG6-P1 salivary peptide, used as the biomarker of Anopheles bite exposure.ResultsThe specific IgG levels to the gSG6-P1 salivary peptide in the rainy season were significantly higher compared to the dry season in all neighbourhoods studied (all p<0.001). Interestingly, these specific IgG levels did not differ between neighbourhoods during the rainy season, whereas significant differences in IgG level were observed in the dry season (p=0.034). ITN use could be a major factor of variation in the specific IgG level. Nevertheless, no difference in specific IgG levels to the gSG6-P1 salivary peptide was observed between children who declared always versus never sleeping under an ITN in each neighbourhood. In addition, the prevalence of P. falciparum in the whole population and immune responders was significantly different between neighbourhoods in each season (p<0.0001).ConclusionThis study highlights the high risk of malaria exposure in African urban settings and the high heterogeneity of child exposure to the Anopheles vector between neighbourhoods in the same city. The Anopheles gSG6-P1 salivary peptide could be a suitable biomarker to accurately and quantitatively assess the risk of malaria transmission in urban areas.

Santé : généralités [050] ; Entomologie médicale / Parasitologie / Virologie [052] ; Urbanisation et sociétés urbaines [102]

COTE D'IVOIRE ; BOUAKE

Fonds IRD [F B010075303]

fdi:010075303