Friday, 7 August 2026, 4:12
San Joaquin County Public Health Services announced that a woman in her 60s has tested positive for West Nile virus. Officials did not disclose where in the county she lives, whether she was hospitalized or her current condition.
The California Department of Public Health updated its statewide infection tracker on July 31, showing 11 human cases in California. San Joaquin County health officials say their case is the 12th.
State data shows six new human cases reported in California in the last week, including two fatalities. On Tuesday, Glenn County officials confirmed the death of a resident who lived in the southern portion of the county. A day earlier, Kings County announced a West Nile virus-related death, the first in the state in 2026.
State surveillance data last updated July 31 shows the county recorded 51 positive mosquito samples, one infected horse and three dead birds. Mosquitoes carrying the virus were first detected locally in June at Upper Jones Tract in the Delta islands west of Stockton. At that time, California had not yet reported any human infections.
Last year, San Joaquin County's first publicly reported human case did not come until October. This year's case arrives much earlier, signaling heightened virus activity.
San Joaquin County residents can report significant mosquito infestations and neglected swimming pools to the San Joaquin County Mosquito and Vector Control District. Property inspections can also be requested through the district's website. Dead birds can be reported to the state by calling 1-877-968-2473. These reports help health agencies track where the virus may be circulating.
West Nile virus is most commonly spread through the bite of an infected mosquito. About 80% of infected people develop no symptoms, while roughly 20% experience flu-like symptoms such as fever, headaches and body aches. About 1% develop a serious illness affecting the brain and nervous system. Adults over 60, people with weakened immune systems and those with diabetes or kidney disease face a higher risk.
County Public Health Officer Dr. Maggie Park urged residents to take precautions around dawn and dusk, when mosquitoes are most active. "If you know you have been bitten by mosquitoes and are exhibiting flu-like symptoms, you should consult with your healthcare provider, especially if you have an immunocompromised health status," Park said.
Health officials recommend using repellents with DEET, picaridin, IR3535 or oil of lemon eucalyptus. Wear long sleeves and pants outdoors, and make sure doors and windows have tightly fitted screens. Drain standing water from yards and other areas, because mosquitoes can reproduce in as little as a tablespoon of water.
The early arrival of West Nile virus in San Joaquin County is a reminder to take prevention seriously. Report dead birds, request property inspections and follow basic mosquito safety steps to protect yourself and your community.
