Viruses can change your scent to make you more attractive to mosquitoes, new research in mice finds: Mosquitoes are the world’s deadliest animal. Over 1 million deaths per year are attributed to mosquito-borne diseases, including malaria, yellow fever, dengue fever, Zika and chikungunya fever. How mosquitoes seek out and feed on their hosts are important factors in how a virus circulates in nature. Mosquitoes spread diseases by acting as carriers of viruses and other pathogens: A mosquito that bites a person infected with a virus can acquire the virus and pass it on to the next person it bites.