Fish Vs Malaria

Edible African fish could help beat malaria, study says | Science | Reuters

From the report:

Researchers have long known that the Nile tilapia feeds on mosquito larvae but the study was the first to test its potential to fight the disease in the field, said Francois Omlin, a researcher at the International Centre of Insect Physiology and Ecology in Nairobi.

"A fish in the field may act differently than a fish in an aquarium and it was important to test how effective it could be," Omlin, who led the study, said in a telephone interview. "The tilapia species was never tested in the field for its ability to eat mosquito larvae."....

In the study, the team cleared three ponds of fish and vegetation in the highlands of Western Kenya and measured the mosquito population before introducing young tilapia.

Ten days later, no malaria mosquito larvae were recorded compared with a similar pond with no tilapia, and 41 weeks after the fish were introduced the number of mosquitoes fell by more than 94 percent, Omlin said.

Seems to have taken an unusually long time for someone to get around to testing their effectiveness.