A High Proportion of Malaria Vector Biting and Resting Indoors despite Extensive LLIN Coverage in Côte d’Ivoire
Naminata Tondossama,
Chiara Virgillito,
Zanakoungo Ibrahima Coulibaly,
Verena Pichler,
Ibrahima Dia,
Alessandra della Torre,
Andre Offianan Touré,
Akré Maurice Adja,
Beniamino Caputo
Affiliations
Naminata Tondossama
Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Chiara Virgillito
Department of Public Health and Infectious Diseases, Institute Pasteur Italia-Fondazione Cenci-Bolognetti, University of Rome ‘Sapienza’, Piazzale Aldo Moro 5, 00185 Rome, Italy
Zanakoungo Ibrahima Coulibaly
Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Verena Pichler
Department of Public Health and Infectious Diseases, Institute Pasteur Italia-Fondazione Cenci-Bolognetti, University of Rome ‘Sapienza’, Piazzale Aldo Moro 5, 00185 Rome, Italy
Ibrahima Dia
Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, Dakar BP 220, Senegal
Alessandra della Torre
Department of Public Health and Infectious Diseases, Institute Pasteur Italia-Fondazione Cenci-Bolognetti, University of Rome ‘Sapienza’, Piazzale Aldo Moro 5, 00185 Rome, Italy
Andre Offianan Touré
Unité de Paludologie, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Akré Maurice Adja
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouët Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Beniamino Caputo
Department of Public Health and Infectious Diseases, Institute Pasteur Italia-Fondazione Cenci-Bolognetti, University of Rome ‘Sapienza’, Piazzale Aldo Moro 5, 00185 Rome, Italy
Malaria is still a leading cause mortality in Côte d’Ivoire despite extensive LLINs coverage. We present the results of an entomological survey conducted in a coastal and in an inland village with the aim to estimate Anopheles gambiae sensu lato (s.l.) female’s abundance indoor/outdoor and Plasmodium falciparum infection rate and analyze the occurrence of blood-feeding in relation to LLINs use. Pyrethrum spray (PSC) and window exit traps (WT) collections were carried out to target endophagic/endophilic and endophagic/exophilic females, respectively. Data on LLINs use in sampled houses were collected. (1) high levels of malaria transmission despite LLINs coverage >70% (~1 An. gambiae s.l. predicted mean/person/night and ~5% Plasmodium falciparum infection rate); (2) 46% of females in the PSC sample were blood-fed, suggesting that they fed on an unprotected host inside the house; (3) 81% of females in WT were unfed, suggesting that they were leaving the house to find an available host. Model estimates that if everyone sleeps under LLINs the probability for a mosquito to bite decreases of 48% and 95% in the coastal and inland village, respectively. The results show a high proportion of mosquito biting and resting indoors despite extensive LLINs. The biological/epidemiological determinants of accounting for these results merit deeper investigations.
