Since the West Nile Virus was first identified in New York in the late nineties, it has been spread by migrating birds to every state except Hawaii and Alaska.

After a mosquito bites a bird infected with West Nile Virus, it can then transmit it to any human. Most people infected will not notice, but about one in five will contract a fever and experience flu-like symptoms. Less than one percent result in a neurological disease that can be fatal. A warming climate, however, magnifies the risk of exposure.

TIETZE: “Mosquitoes are cold blooded, so the warmer it gets, the faster they develop, and they’ll produce more eggs, and there will be more female mosquitoes biting people and potentially transmitting the disease.”

That’s Noor Tietze of the Santa Clara County Vector Control District in California. He explains mosquitoes also thrive during a drought.

TIETZE: “The water is not flowing very much, it’s stagnating more. There’s a lot of organic material there that provides them their larvae food source so their numbers are increased.”

With no way yet to treat West Nile Virus, it’s important to use bug repellent and wear protective clothing during mosquito season — especially as warm spells and droughts become more common.


Reporting credit: ChavoBart Digital Media.
Photo source: Wikipedia.

More Resources
California West Nile Virus website
Santa Clara Vector Control District

Sara Peach is the editor-in-chief of Yale Climate Connections. She is an environmental journalist whose work has appeared in National Geographic, Scientific American, Environmental Health News, Grist,...