National Pesticide Information Center



Diseases Transmitted by Mosquitoes

Some mosquitoes are vectors for diseases. This means they can transmit diseases from one human or animal to another. Typically, the diseases are caused by viruses or tiny parasites. For example, a mosquito that bites an infected human or animal can pick up a virus along with the blood meal. The mosquito and virus do not harm one another but the virus reproduces inside the mosquito. Later, the mosquito can pass the viruses to other humans when biting them.

If you're planning a trip and you're wondering how to protect yourself from vector-borne illness, try visiting the Centers for Disease Control and Prevention's Travelers' Health page.

West Nile Virus


Dengue Fever


Dog Heartworm

Other Diseases

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If you have questions about this, or any pesticide-related topic, please call NPIC at 1-800-858-7378 (8:00am - 12:00pm PST), or email at npic@ace.orst.edu.

Last updated April 1, 2015