Plasmodium-associated changes in human odor attract mosquitoes

Abstract

Malaria parasites () can change the attractiveness of their vertebrate hosts to vectors, leading to a greater number of vector-host contacts and increased transmission. Indeed, naturally-infected children have been shown to attract more mosquitoes than parasite-free children. Here, we demonstrate -induced increases in the attractiveness of skin odor in Kenyan children and reveal quantitative differences in the production of specific odor components in infected vs. parasite-free individuals. We found the aldehydes heptanal, octanal, and nonanal to be produced in greater amounts by infected individuals and detected by mosquito antennae. In behavioral experiments, we demonstrated that these, and other,-induced aldehydes enhanced the attractiveness of a synthetic odor blend mimicking "healthy" human odor. Heptanal alone increased the attractiveness of "parasite-free" natural human odor. Should the increased production of these aldehydes by -infected humans lead to increased mosquito biting in a natural setting, this would likely affect the transmission of malaria.

Optimisation and field validation of odour-baited traps for surveillance of Aedes aegypti adults in Paramaribo, Suriname

“…Covariates associated with the experimental design (mosquito age, day and time of mosquito release, temperature, relative humidity, airflow and trap position) were tested but removed from the model when not significant (P > 0.05). In laboratory experiments 2 and 3 we used the 95% CI of the predicted proportion of mosquitoes choosing a specific treatment, derived from the GLM, to assess if mosquito choice differed significantly from a 50:50 distribution [46].…”

Extreme Competence: Keystone Hosts of Infections

“…For instance, high parasitemia often increases transmission probability, but exceptionally high parasitemia can negatively impact vector lifespans [33], meaning that intermediate parasite burden might be most transmissible. Malaria parasites can increase host CO 2 and volatile compound output [34], making them more conspicuous to vectors. Altogether for malaria, then, the most competent host would be one that is attractive to infected vectors when uninfected, attractive to uninfected vectors when infectious, and able to generate and tolerate a high enough parasite burden that parasites are taken up in vector bites.…”

Effects of travel frequency on the persistence of mosquito-borne diseases

“…A small proportion of people who make disproportionately more journeys than others may accelerate the global spread of epidemics [26]. Meanwhile, the number of bites a person received per unit time is affected by many factors such as blood type [2], health status [39], quality of bed nets [43], age or host size [37], and skin color [24].…”