Mosquito West Nile Virus Bug Leaf Syed Ali Unsplash.jpg

A dead bird found in Pleasanton has tested positive for the West Nile virus, according to the Alameda County Mosquito Abatement District.

The bird, which was tested on Sept. 27, is the first indication this year of the active transmission of the virus in the county. In response, the district is increasing mosquito monitoring and larval control efforts in the area where the bird was discovered. West Nile virus is transmitted to people and animals through the bite of an infected mosquito.

“With the change of season, residents may assume mosquitoes are no longer a threat, but this is usually the time of year when we see an increase in West Nile virus in our county,” said General Manager Ryan Clausnitzer. “With light showers in the mornings followed by warm weather in the afternoons, mosquitoes still have plenty of opportunities to breed and flourish.”

Clausnitzer urged residents to eliminate standing water from their property and protect themselves from mosquito bites by wearing repellent and long and loose clothing.

“While we are not detecting high numbers of mosquitoes in the area where the bird was found, there is an increased risk of West Nile virus with every mosquito bite,” Clausnitzer said.

As of Monday, 57 people in California had tested positive for West Nile virus, according to the mosquito district. Symptoms can include fever, headache, body aches, joint pains, vomiting, or rash. Although there is no known cure for the virus, less than 1% of those infected develop a serious neurological illness, such as encephalitis or meningitis.

For more information about mosquitoes, West Nile virus, or to request district services, visit or call 510-783-7744.