Health News of Friday, 17 May 2013
Source: Plos One/BBC
Mosquitoes infected with the malaria-causing parasite P. falciparum have an increased ability to smell human beings' body odour, making it easier to find their victims and infect them with malaria, according to a new study reported by the BBC.
Researchers from the London School of Hygiene and Tropical Medicine (LSHTM) in the UK found that infected insects were three times more likely to be lured towards human scent than uninfected ones.
Dr James Logan, from the London School of Hygiene and Tropical Medicine (LSHTM), told the BBC: "One thing that always surprises me about parasites is how clever they are. They are these ever-evolving organisms that seem to be one step ahead of us the whole time."
To carry out the study, the researchers infected malaria mosquitoes (Anopheles gambiae) with the most deadly form of parasite, Plasmodium falciparum.
They placed about 100 of the infected insects into a container, along with some nylon stockings that had been previously worn by volunteers for 20 hours.
"It is a very effective way of collecting body odour... the odour can remain attractive for months," explained Dr Logan.
The scientists repeated the experiment with uninfected insects.
They found that mosquitoes carrying the deadly parasite were three times more likely to be attracted to the smelly stockings.
The scientists believe this is because the tiny parasitic organisms are manipulating their hosts' sense of smell.
Dr Logan said: "We think it is giving them a heightened sense of smell. We are hypothesising there is an alteration somewhere in their olfactory system that allows them to find us quicker."
By making humans an easier target, the parasite is more likely to be passed into the blood stream - ensuring its survival and continuing the spread of the deadly disease.