The discovery of three birds that tested positive for the disease has signaled the start of the West Nile virus season, the Santa Clara County Vector Control district reported Friday, making Santa Clara only the third county in the state to find the deadly virus so far this year.
Since 2004, the disease has killed 174 Californians and infected nearly 5,000.
The birds, American crows, were found March 19 and 20 in San Jose (zip codes 95124 and 95123), and March 20 in Cupertino (zip code 95014).
None was found in south Santa Clara County.
In 2014, Santa Clara County identified 11 human WNV cases and 925 dead birds tested positive for the illness, which is spread by mosquito bites. It was the county’s highest ever yearly incidence of WNV.
The only human case in South County was in Morgan Hill. None was fatal and only a “handful” of birds tested positive in South County last year, according to Denise Bonilla, manager of the Santa Clara County Vector Control District.
Alameda County has reported one infected dead bird and is the only other county to report the disease in a bird so far this year in California.
In Los Angeles County the virus showed up in a mosquito pool, according to the California Department of Public Health website, WestNile.ca.gov.
Reporting in South County is not as robust as in the rest of the county, Bonilla said. She urged residents here to report dead birds for testing and to help eliminate mosquitoes before they reach adulthood.
“It is important to remain vigilant by taking practical steps to eliminate mosquito breeding areas,” said Bonilla.
“Residents can help by dumping or draining standing water on their properties,” she said, adding that insects in their larvae and pupal stages are the “focus of our surveillance” efforts.
The focus on finding and eliminating immature mosquitoes extends to South County where the district has a crew that actively seeks the insects and responds to calls from residents, according to Bonilla.
Backyard pools when not properly cared for can produce millions of mosquitoes, according to the district, so it provides mosquito-eating fish for pools, ponds, horse troughs and other water containers. Requests for fish can be made by email at
ve********@de*.org
or at (408) 918-4770.
“A bird that tests positive for WNV alerts health officials that the virus is active in an area. Santa Clara County residents are requested toreport dead birds online atwww.westnile.ca.gov. The vector district will pick up and test dead crows, ravens, jays and magpies that have been dead for less than 48 hours,” the district said in a press release.
WNV causes mild to severe flu-like symptoms such as fever, headache and body ache. In severe cases, it can cause significant neurological symptoms or even death, according to the district. The elderly and people with compromised immune systems are most susceptible to serious cases; human infections typically happen in the summer, according to the district.
For more about WNV prevention and vector control, go to, www.sccvector.org.
The district recommends the following measures to guard against mosquito bites:
Protect yourself if outside when the insects are most active, at dawn and the first two hours after sunset; when outside, wear long pants and long-sleeved shirts; use insect repellent with DEET, oil of lemon eucalyptus, IR3535, or picaridin, according to label instructions; make sure doors and windows have tight-fitting screens and no holes or tears; and contact the vector control district if you are being bothered by mosquitoes or know of a potential mosquito-breeding source.
