Mosquito saliva might be even more important for spreading infection than anyone thought, NBC News reported.
Two studies published in the past week show that mosquito saliva lures immune cells to the site of a bite, and tricks them into spreading any viruses, such as Zika virus, throughout the body.
Tests in mice show that mosquito spit is such an important factor that it could sometimes turn a normally benign viral infection deadly.
"Mosquito bites are not just annoying — they are key for how these viruses spread around your body and cause disease," said Clive McKimmie, an expert on viruses at the University of Leeds in Britain who led one of the studies.
Mosquitoes transmit some of the biggest killer diseases, from malaria to yellow fever. There's no treatment and no vaccine against Zika or dengue, although some are in the works.