Attraction of mosquitoes to primate odours and implications for zoonotic Plasmodium transmission.

J W Bakker,B H Hahn,D E Loy,N O Verhulst,W Takken

doi:10.1111/mve.12402

Abstract

Vector‐borne diseases often originate from wildlife and can spill over into the human population. One of the most important determinants of vector‐borne disease transmission is the host preference of mosquitoes. Mosquitoes with a specialised host preference are guided by body odours to find their hosts in addition to carbon dioxide. Little is known about the role of mosquito host preference in the spillover of pathogenic agents from humans towards animals and vice versa. In the Republic of Congo, the attraction of mosquitoes to primate host odours was determined, as well as their possible role as malaria vectors, using odour‐baited traps mimicking the potential hosts of mosquitoes. Most of the mosquito species caught showed a generalistic host preference. Anopheles obscurus was the most abundant Anopheles mosquito, with a generalistic host preference observed from the olfactory response and the detection of various Plasmodium parasites. Interestingly, Culex decens showed a much higher attraction towards chimpanzee odours than to human or cow odours. Human Plasmodium parasites were observed in both human and chimpanzee blood, although not in the Anopheles mosquitoes that were collected. Understanding the role of mosquito host preference for cross‐species parasite transmission provides information that will help to determine the risk of spillover of vector‐borne diseases.

Highlights

Many of the most deadly human diseases, including malaria, Zika virus, dengue virus and chikungunya virus, are transmitted by mosquitoes (Takken & Knols 1999; Harrington et al, 2001; Lambrechts et al, 2010; Fauci and Morens, 2016)
Studies of Plasmodium parasites in African great apes revealed that the malaria parasites Plasmodium falciparum and Plasmodium vivax, which together account for the majority of global malaria cases (WHO World Malaria Report 2018), both originated from parasites that infect African great apes (Liu et al, 2010, 2014; Loy et al, 2018a)
The remaining Anopheles mosquitoes were identified as Anopheles paludis, Anopheles moucheti, Anopheles ziemanni, Anopheles gambiae s.l. and Anopheles nili

Summary

Introduction

Many of the most deadly human diseases, including malaria, Zika virus, dengue virus and chikungunya virus, are transmitted by mosquitoes (Takken & Knols 1999; Harrington et al, 2001; Lambrechts et al, 2010; Fauci and Morens, 2016). In addition to transmitting diseases between human hosts, mosquitoes facilitate the spillover of zoonotic pathogens into human populations (Jones et al, 2008). As the closest relatives of Homo sapiens, great apes are of interest as potential reservoirs of zoonotic vector-borne pathogens themselves, and mosquitoes may act as a bridge vector between great ape reservoirs of such pathogens and humans. There is, a fundamental gap in knowledge concerning the transmission dynamics of vector-borne diseases between great apes and humans, as well as the potential zoonotic threat that they pose to humans. African great apes are infected with at least 13 Plasmodium species, which are further subdivided into the Laverania and Plasmodium subgenera (Liu et al, 2010, 2014, 2016; Loy et al, 2016,2017).

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