New mosquito type presents challenge in fighting malaria

LONDON - Scientists in France have identified a new type of mosquito in Africa and say it could further complicate the fight to control malaria.

It is a subgroup of Anopheles gambiae, the insect species behind most of the malaria transmission in Africa.

Michelle Riehle, from the Pasteur Institute in Paris, France, and colleagues said that this new mosquito appears to be very susceptible to the parasite that causes the disease - which raises concern.

The type may have evaded classification until now because it rests away from human dwellings where most scientific collections tend to be made.

The researchers made their discovery in Burkina Faso, where they gathered mosquitoes from ponds and puddles near villages over a period of four years, reports the BBC.

When they examined these insects in the lab, they found many to be genetically distinct from any A. gambiae insects previously recorded.

The team grew generations of the unique subtype in the lab to assess their susceptibility to the malaria parasite and this revealed them to be especially vulnerable, more so than indoor-resting insect types.

But Pasteur team-member Ken Vernick cautioned that these mosquitoes’ significance for malaria transmission had yet to be established.

“We are in a zone where we need to do some footwork in the field to identify a means to capture the wild adults of the outdoor-resting sub-group.

“Then we can test them and measure their level of infection with malaria, and then we can put a number on how much - if any - of the actual malaria transmission this outdoor-resting subgroup is responsible for,” he said.

The researchers reported that the new subgroup could be quite a recent development in mosquito evolution and urge further investigation to understand better the consequences for malaria control.

They also emphasise the need for more diverse collection strategies. The subtype is likely to have been missed, they say, because of the widespread practice of collecting mosquitoes for study inside houses. In one sense this has made sense - after biting, mosquitoes need to rest up and if they do this inside dwellings, the confined area will make them an easier target for trapping.

The research has been reported in Science magazine. (ANI)