Lake County has plenty of water and even more mosquitoes. Being bitten by a mosquito comes with the territory of being outdoors and most of the time that bite means a slight itch and a small pimple at the source of the bite. However, that bite now carries a chance of getting West Nile Virus.
West Nile Virus (WNV) is a mosquito-borne disease common in Africa, West Asia, the Middle East and more recently North America. A human infected with WNV can become seriously ill or even die. Experts believe WNV is a seasonal epidemic in North America that flares up in the summer and continues into the fall.
WNV was first discovered in the United States in New York in 1999 when birds started dying in the Bronx Zoo. It has since spread to 48 states, with only Alaska and Hawaii spared the disease thus far. Nationwide there were 2,448 human cases of WNV last year, including 84 deaths.
West Nile Virus got its name in 1937 when a woman living near the Nile River in Uganda died from the disease. It first showed up in California in 2002, but there was only one case. However, the virus had spread to all 58 counties in the state by 2004 and 830 humans had been infected. According to Lake County Vector Control District manager Jamie Scott, there have been 15 incidents where WNV has been detected in mosquitoes and birds so far this year. No humans in the county have tested positive for WNV to date. One human in the county contacted the disease last year and one person has died this year from WNV in neighboring Glenn County.
The primary mosquito that spreads the disease in Lake County is the western encephalitis mosquito. The mosquito gets the virus when it bites an infected bird such as a raven or crow. The mosquito then bites a human, transferring the virus. Scotts said that humans can”t spread the disease most of the time.
California is equipped to detect, monitor and respond to WNV through ongoing collaboration between more than 100 public agencies. The California surveillance system includes human and horse case detection and testing of mosquitoes, sentinel chicken flocks and dead birds.
Humans cannot spread the disease through causal contact such as kissing or touching. However, it can be spread through blood transfusions. All blood is now checked for WNV before being used. Typically a person develops systems of WNV between three of 14 days after being bitten by an infected mosquito. The symptoms of WNV vary but usually include a slight fever, headache, body aches, nausea, vomiting and swollen lymph glands. These symptoms normally last a few days. Approximately 80 percent of people will have no symptoms. Less than 1 percent infected with WNV will develop more serious symptoms such as high fever and convulsions that can result in neurological damage.
There is no specific treatment for WNV. In most cases the person is given intravenous fluids and nursing care. As with many infections those who are elderly and whose immune systems are compromised are most at risk.
It”s not just humans who can get infected by WNV but animals as well, especially horses. Approximately one-third of the horses infected either die or have to be euthanized. The good news is there is a vaccine for horses. Dogs and cats rarely get WNV.
Scott said the best prevention for WNV is to use insect repellents when outside. Repellents containing DEET work very well in keeping mosquitoes away. Mosquitoes carrying WNV are most active at dawn and dusk. Make sure you don”t have any old standing water in your yard such as birdbaths and small decorative ponds. Scott said that Vector Control technicians will visit your property and offer assistance if you have ponds or birdbaths with standing water. They will either treat the ponds or give mosquito fish to the homeowner. The service is free. There is also a solution available that can be placed in backyard ponds and it will kill the mosquitoes. It”s called “Mosquito Dunks” and can be purchased at Mendo Mill Hardware in Lakeport and Clearlake. A package of the tablets costs $12. For more information on dealing with mosquitoes and WVN call Vector Control at 263-4770.
