California Sees 373 West Nile-Positive Birds as Dengue and Typhus Risks Spread
Updated
Updated · Los Angeles Times · Aug 16
California Sees 373 West Nile-Positive Birds as Dengue and Typhus Risks Spread
3 articles · Updated · Los Angeles Times · Aug 16
Summary
California’s vector-borne disease threat is widening beyond West Nile, with dengue and flea-borne typhus also rising as health experts warn the state is becoming more hospitable to disease-carrying insects.
373 West Nile-positive dead birds had been reported statewide by mid-August, up from 76 a year earlier, after a record March heat wave boosted Culex mosquitoes; nationally, 181 human cases were confirmed, 129 neuroinvasive.
18.2 million Californians already live in areas suitable for local dengue transmission at least one month a year, and a Lancet study said another 4.1 million could be at risk by mid-century.
220 typhus cases were confirmed in Los Angeles County in 2025, up from 187 in 2024, while a Marin County park closed for weeks after a flea infestation highlighted expanding exposure.
Experts said no single cause explains the surge, but warming temperatures, longer vector seasons, improved detection and deeper human encroachment into wildlife habitats are all increasing disease contact.