Overview
- Federal data show 48 confirmed human West Nile cases and virus activity in 23 states as of June 30, the highest early-season total in more than two decades.
- Local surveillance has found rising numbers of infected mosquito pools and dead birds, with Southern Nevada reporting 10 new positive pools and California counties from Sacramento to Orange and San Diego confirming positive traps.
- Sacramento County confirmed its first human West Nile case of 2026, a 60-year-old woman who is recovering as vector control officials step up trapping, testing and targeted spraying.
- A Maryland firm, Bee Safe Mosquito Control, is releasing about 600,000 non-biting, Wolbachia-infected male ‘ZAP’ Aedes albopictus in the Washington, D.C. region between June and September to reduce Aedes populations by causing sterile matings.
- Health officials urge personal prevention—EPA-registered repellents, screens, removing standing water and avoiding dawn and dusk—while noting there is no licensed human vaccine or specific antiviral treatment and that Aedes-targeted Wolbachia releases will have limited direct, immediate impact on West Nile transmission driven mainly by Culex mosquitoes.