Tuesday, September 18, 2012

New Malaria-Transmitting Mosquito

Anopheles sp.
Potentially bad news for the fight against malaria in Kenya. A group of Scientists from the London School of Hygiene and Tropical Medicine, have discovered  what looks like a new species of Anopheles. They used DNA Barcodes (COI) and the nuclear marker ITS2. Their analysis indicated that the DNA from mosquitoes that did not resemble ay other specimens differed from sequences available for known malaria-transmitting mosquitoes in Africa.

About half of the mosquitoes collected did not match the morphologic descriptions of any of the more recently identified species nor did their DNA Barcode match any sequences in the public databases. Some of those specimens were also tested positive for Plasmodium falciparum sporozoites. 

The most alarming find is that this putative new species was found to be active outdoors and bite people earlier in the evening soon after sunset while the commonly caught Anopheles mosquitoes that transmit malaria in Africa, generally, prefer to rest indoors and feed on humans at night. This led to the development of programs to stop the spread of malaria such as spraying insecticide in homes and issuing bed nets for people. The outdoor activity of these mosquitoes could lead to the failure of current indoor-based interventions to control this species, and it could therefore contribute to malaria parasite transmission in the area.

These findings highlight the value of an integrated approach, here including behavior and DNA Barcoding. Morphology alone would not have given the scientists this essential piece of information which will hopefully allow the implementation of appropriate, and therefore successful, malaria control interventions.

No comments:

Post a Comment