West Nile virus widespread in Butte County

From the Chico Enterprise-Record
August 31, 2021

CHICO — In Butte County, seven new pools of West Nile virus have been found while four sentinel chickens have tested positive for the virus. The West Nile virus has resulted in one death in Butte County so far this year.

Butte County Mosquito and Vector Control District said the virus is considered “widespread” among mosquitoes in the county with this year seeing 76 positive pools. The highest year on record was 2015 when 101 mosquito pools with active cases of West Nile virus were found.

“2015 was the fourth year of the drought,” said Butte County Mosquito and Vector Control District Manager Matt Ball. “One would think droughts mean less mosquitoes therefore there should be less virus. Well, here in Butte County, droughts actually mean propagation of the virus and it means more artificial water, flooding and irrigating sooner than natural weather. We actually see more mosquitoes and more virus on drought years than when we get a nice cool wet spring.”

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