Fungal pesticides may reduce malaria transmission

Mosquitoes carrying a Malaria parasite that were exposed to surfaces coated with fungus-based pesticides had a dramatically reduced ability to transmit malaria, according to a new study.

Fungal pesticide sprays "might replace or supplement chemical insecticides for Malaria control, particularly in areas of high insecticide resistance," senior author Dr. Matt B. Thomas, from Imperial College London, and colleagues write in the journal Science.

The researchers used rodents to assess the effect that various fungal pesticides had on reducing mosquito-borne transmission of Plasmodium chabaudi, a malaria parasite that affects rodents.

Exposure to surfaces treated with the fungal pesticides reduced the number of mosquitoes that were able to transmit malaria by a factor of about 80, the researchers found. Moreover, with exposure periods comparable to what is likely to occur in natural settings, greater than 90 percent mosquito mortality rates were achieved.

In a related study, Dr. Bart G. J. Knols, from Wageningen University in the Netherlands, and colleagues showed that a control strategy using fungal insect pathogens can be implemented in Africa, at the rural village level, and could markedly reduce malaria transmission rates.

SOURCE: Science, June 10, 2005.