Mosquitoes biting a malaria-carrying host coax the malaria parasite to come out of hiding, resulting in greater disease transmission.
Sylvain Gandon at the National Centre of Scientific Research in Montpellier, France, and his colleagues infected canaries (Serinus canaria) with a malaria parasite that is specific to birds (Plasmodium relictum), and then exposed them to mosquitoes that were not carrying the parasite.
After the birds were bitten by malaria-free insects, the level of parasites rose in the birds' blood. Mosquitoes that subsequently bit birds were more likely to pick up and transmit the parasite than insects attacking birds that had not been initially bitten.
The researchers conclude that mosquito bites trigger Plasmodium to emerge from its dormant stage.