LAKEPORT, Calif. – One mosquito sample collected in Lake County has tested positive for West Nile virus this week, health officials reported Friday.
The mosquitoes, Culex tarsalis, or Western encephalitis mosquito, were collected in Lower Lake on July 26, according to the Lake County Vector Control District.
The district reported that this is the first detection of WNV in Lake County in 2018.
The Lake County Vector Control District traps and tests mosquitoes throughout the county to identify the areas that have the highest risk, and targets those areas for source reduction and treatment using an integrated vector management program.
“The hot weather we’ve had this summer is perfect for both West Nile virus and mosquitoes to multiply quickly,” said Jamesina Scott, Ph.D., district manager and research director of the Lake County Vector Control District. “This is the first West Nile virus we’ve found in Lake County this year, and in most years, we continue to find West Nile virus into September.”
No other West Nile virus activity has been detected in Lake County yet this year. Statewide, 24 California counties have detected WNV this year, mainly in mosquitoes. Twelve human cases of West Nile virus illness have been reported in California residents this year.
While less than 1 percent of individuals – about 1 in 150 people – infected with West Nile virus will develop severe illness from West Nile virus infection, the disease can cause symptoms that can last for several weeks, and neurologic effects can be permanent. In some individuals, the infection can be fatal. People over age 50 and diabetics are at risk for the more severe forms of the disease.
The most recent confirmed case of WNV infection in Lake County was in 2016.
“Since there is no West Nile Virus vaccine for humans, the best protection is to prevent mosquito bites,” says Lake County Deputy Health Officer Dr. Erin Gustafson. “All residents of Lake County should get in the habit of taking precautions against mosquito bites while mosquitoes are active. We are fortunate to have had only a few cases of human illness, but finding the virus in mosquitoes is a reminder that we must take precautions throughout the WNV season.”
“You can reduce your risk of catching the infection by staying indoors during early morning and evening hours, keeping window screens in good repair, wearing protective clothing and use of insect repellents according to package instructions,” according to Dr. Gustafson.
“Other steps you can take to protect your family from West Nile virus are dumping or draining containers of water, using mosquito repellent, and contacting the District to get mosquitofish if you have a pool or spa that isn’t being maintained,” Dr. Scott recommended.
Mosquitoes that transmit WNV develop in the water in out-of-service swimming pools and spas, animal watering troughs, ornamental ponds, rain barrels, and other sources of standing water. The district has free mosquito-eating fish to control mosquitoes in these sources.
Residents with questions or who would like help with a mosquito problem, including reporting a neglected pool or spa, should contact the Lake County Vector Control District at 707-263-4770 or visit www.lcvcd.org.
For more information about West Nile virus, visit http://www.westnile.ca.gov/. Information about mosquito repellents can be found on the US Centers for Disease Control and Prevention Web site at http://www.cdc.gov/westnile/faq/repellent.html.