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West Nile Virus: Human Cases Rise, First Death in CA

9/1/2025

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Summary

Story summary

West Nile virus, first identified in Pennsylvania in 2000, primarily affects birds and is spread by infected mosquitoes.
In 2025, Pennsylvania reported 19 human cases, while Dane County, Wisconsin, had its first case, resulting in one hospitalization.
Butte County, California, confirmed its first human death from West Nile this season, prompting efforts to reduce mosquito populations.

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Story summary

West Nile virus, first identified in Pennsylvania in 2000, primarily affects birds and is spread by infected mosquitoes.
In 2025, Pennsylvania reported 19 human cases, while Dane County, Wisconsin, had its first case, resulting in one hospitalization.
Butte County, California, confirmed its first human death from West Nile this season, prompting efforts to reduce mosquito populations.