First detection of the malaria vector Anopheles arabiensis in Cote d'Ivoire : urbanization in question

2022

Article référencé dans le Web of Science WOS:000861472400001

Fournet Florence, Adja A. M., Adou K. A., Dahoui M. M. C., Coulibaly B., Assouho K. F., Zoh D. D., Kone M., Kone A., Niamien K. L., Cornélie Sylvie, Tia E., Moiroux Nicolas

Malaria Journal, 2022, 21 (1), 275 [8 p.]

Background Previous studies have revealed high malaria transmission in Bouake, Cote d'Ivoire. The sociopolitical crisis in the country and the resulting environmental changes have raised the need to update existing knowledge on mosquito vector species and malaria transmission. Methods Adult mosquitoes were caught using the human landing catch (HLC) sampling method in Bouake. They were collected in six districts representative of the diversity in urban landscapes. Sampling points were selected along the water network crossing the city and monitored from 2020 to 2021 to detect the presence of anopheline larvae. PCR techniques were used to ascertain the species of the Anopheles gambiae complex, Plasmodium falciparum sporozoite infection in a subset of Anopheles vectors, and insecticide resistance mechanisms in Anopheles arabiensis only. Results A total of 4599 Anopheles mosquitoes were collected and then identified. Anopheles gambiae sensu lato (s.l.) made up the majority of the whole collection (99%) while Anopheles funestus (0.7%), Anopheles ziemanni (0.2%), Anopheles pharoensis (0.2%) represented the remaining proportion of collection. Among the Anopheles gambiae complex, three species were identified namely An. gambiae sensu stricto (45.9%), Anopheles coluzzii (52.2%), and Anopheles arabiensis (1.9%). The first two species had already been collected in Bouake, however this is the first time that An. arabiensis is reported in Cote d'Ivoire. Anopheles arabiensis was also collected during the larval surveys in a similar proportion (1.1%) in the same areas as the adults. Conclusions This study detected the presence of An. arabiensis for the first time in Cote d'Ivoire. This species was found quite far from its usual geographic area and its expansion could be linked to the urbanization process. Although no An. arabiensis was found to be infected by Plasmodium sp., its role in malaria transmission in Bouake has to be explored, particularly since its exophagic behaviour raises the issue of control measures and the use of insecticide-impregnated nets. The spread of this species in Cote d'Ivoire should be assessed through further research in additional towns in the country.

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

COTE D'IVOIRE ; BOUAKE

Fonds IRD [F B010086311]

fdi:010086311