Drug could kill mosquitoes when they feast on human blood

Ivermectin, the 30-year-old antiparasitic drug whose discovery was honored with a Nobel Prize last month, may have another trick up its sleeve: killing mosquitoes.

A new study in Burkina Faso suggests that mass-administering ivermectin to people may kill or weaken the mosquitoes feeding on them, and thus make a dent in malaria transmission.

Ivermectin is best known for killing roundworms, including the ones that cause river blindness and the leading cause of elephantiasis. But researchers have known for decades that the drug also kills insects if they ingest it.

Brian Foy, a medical entomologist at Colorado State University, Fort Collins, believes that makes it a prime candidate in the fight against malaria. If enough people in an area have ivermectin in their blood, says Foy, some of the female mosquitoes that bite them will die, whereas others will be too weakened to pass on the malaria parasite. Foy has shown in lab studies that the approach holds promise, and co-founded a research network last year to study the concept further.

The trial is still ongoing and will conclude in November. But an interim analysis presented today by Foy and Dabiré at the annual meeting of the American Society of Tropical Medicine and Hygiene suggests that the drug is already having an impact.