A mosquito carrying a possibly debilitating virus rarely seen in Northern California has been found in the town of Plumas Lake, 30 miles north of Sacramento, local health officials said Monday. The virus is spread through bites from infected mosquitoes, and symptoms include fever, headache, nausea and vomiting.
According to the U.S. Centers for Disease Control and Prevention, many people do not experience any symptoms after being bitten by mosquitoes with St. Louis encephalitis. But, in some serious cases, the virus can cause infections in the central nervous system and even lead to death.
The Sutter-Yuba Mosquito and Vector Control District learned Friday evening that a culex mosquito in Yuba County had tested positive for the virus, the first time in the area, said Steve Abshier, the district’s general foreman. The culex mosquito can also carry West Nile virus and Japanese encephalitis.
Mosquitoes with St. Louis encephalitis have also been reported in central and southern California. The virus is transmitted from infected birds to mosquitoes, which means it’s likely an infected bird traveling north to the Sacramento area was bitten by a mosquito, Abshier said. The virus cannot be transmitted by mosquito between people.
The Sutter-Yuba Mosquito and Vector Control District has deployed 16 traps that use light and carbon dioxide emitted from dry ice to attract mosquitoes. “This will help us determine if it is more pervasive or an isolated incident,” Abshier said.
In the meantime, to reduce the risk of infection, the town of Plumas Lake will be sprayed with a compound to kill larvae on Monday and Thursday evenings. Agricultural lands in Yuba County will also be sprayed.
Areas of standing water are prime breeding ground for mosquito larvae, so underground drainage areas have been treated with a compound that’s released over 150 days to kill the larvae, Abshier said. The mosquito and vector control district has also used an aerial photographer to identify and treat more than 80 swimming pools.
To prevent mosquito bites, health officials recommend people wear mosquito repellent that contains DEET and long-sleeved clothing. Also, people should avoid going outside during dawn and dusk when mosquitoes are the most active. To keep mosquitoes out of your home, screens on doors and windows should be checked for any tears, and standing water should be drained.