Two plagues in California, fires and foreclosures, may be increasing the risk of another: West Nile virus. Wildfires have sullied the air in the Sacramento area so badly that officials there have held off aerial spraying of insecticide to combat the virus, which is spread to humans and animals by infected mosquitoes.
At the same time, backyard pools left with standing water in abandoned, foreclosed properties have created a breeding ground for mosquitoes, raising the risk of West Nile infection.
The Sacramento-Yolo County Mosquito and Vector Control District held off aerial spraying of mosquito insecticide last week because of concerns that particulate matter from fires would bind with the insecticide, making it ineffective against the pests. It plans to start spraying on Wednesday.
David Brown, president of the Mosquito and Vector Control Association of California and manager of the Sacramento-Yolo Vector Control District, said the rate of infected mosquitoes in the Sacramento area is "pretty high - more than 10 in 1,000," making West Nile virus a significant concern.
But while a delay in spraying may have increased the risk of virus, Brown added, "One thing that may have been in our favor with all the smoke last week is that people stayed indoors."
To combat mosquitoes in standing water, officials in Sacramento and other parts of the state are turning to a tiny fish, the Gambusia affinis, which devours mosquito larvae.
But in San Diego County, the fish is late to breed and in short supply. Officials there can't expect to fill their demand until late July or early August.
West Nile is widespread in Africa and the Mideast. It arrived in the United States in 1999.
In 80 percent of the cases, people infected with West Nile have no symptoms. But about 20 percent of those infected experience mild symptoms such as headache, fever and nausea. In less than one percent of cases, West Nile virus can lead to paralysis, even death.
The state has confirmed three human cases in California so far this year - two in Stanislaus County and one in Tulare County.
