Scientists have demonstrated for the first time that female mosquitoes infected with malaria parasites are significantly more attracted to human odour than uninfected mosquitoes.
The finding may aid development of tools against the parasite with crucial chemicals found in human odour.
Researchers led by the London School of Hygiene & Tropical Medicine in a laboratory setting showed that infected female Anopheles gambiae sensu stricto mosquitoes were attracted to human odours three times more than mosquitoes that were not infected with the malaria-causing Plasmodium falciparum parasite.
The rate of landing and biting attempts for infected mosquitoes was around three times greater than uninfected mosquitoes.
The study was conducted in collaboration with Wageningen University and Radboud University Nijmegen Medical Centre in the Netherlands.
The team led by Dr James Logan's team is investigating how being infected with malaria could cause the mosquitoes to behave differently.
If the parasites are manipulating the mosquitoes' sense of smell, increasing the chance they will bite when the parasite is transmissible, then the malaria is more likely to spread.
Scientists hope the research will enable the identification of the chemical compounds in human odour to which mosquitoes are attracted and to determine whether infected mosquitoes respond differently to those compounds.
This will provide information that could be used to illuminate how malaria is spread from human to human by parasite-infected female mosquitoes which bite people to feed on blood they need in order to reproduce.
Significantly, the results could help identify new compounds which could be used to develop improved mosquito traps that could specifically target malaria-infected mosquitoes before they have the chance to pass on the parasite to the people they bite.
"It has previously been shown that parasites are able to manipulate the behaviour of insects involved in their transmission and reproductive survival. For example, malaria-infected mosquitoes take larger blood meals than uninfected ones, and will take multiple blood meals," said Logan, Senior Lecturer in Medical Entomology and Chief Scientific Officer for arctec, at the London School of Hygiene & Tropical Medicine.
"We have now shown for the first time that the sense of smell could hold the key to understanding how the parasite successfully manipulates the mosquito to ensure its spread," Logan said.
The study was published in journal PLOS ONE.
