Female mosquitoes infected with malaria parasites are significantly more attracted to human odour than uninfected mosquitoes. This was demonstrated in a laboratory setting in which 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 pilot study was conducted in collaboration with Wageningen University and Radboud University Nijmegen Medical Centre in the Netherlands.
Dr James Logan’s team has been awarded a three-year grant by the Biotechnology and Biological Sciences Research Council (BBSRC) to investigate 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.
The scientists, who will work collaboratively with Rothamsted Research, Wageningen University and Radboud University, hope their 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 – a disease which causes more than half a million deaths a year – 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.
Source: London School of Hygiene & Tropical Medicine, UK