For those scared of sharks ...“The number of mosquito-caused deaths really is a mind-blowing thing. Other than humans killing humans during periods of war, most years, the mosquito wins,” The reason? Mosquitoes carry diseases, including: Malaria, dengue fever virus, Rift Valley fever virus, yellow fever, West Nile virus, Lymphatic filariasis, and Japanese encephalitis. These mosquito-borne infections don’t just kill — they debilitate millions of people and more than 700k die from the disease.