The first confirmed case of the West Nile virus in Colorado in 2009 was confirmed last week in Jefferson County, according to the county health department.
Jeffco public health spokeswoman Kodi Bryant said the case was confirmed in late June in an Arvada man who is recovering at home and expected to make a full recovery.
"West Nile virus season is here, and everyone should take precautions," said Jim Dale, director of the Jeffco health department's environmental health services. "Eliminating mosquito breeding grounds in backyards, wearing insect repellent and using other methods to avoid mosquito bites when outdoors can help minimize risk of infection."
State and local health departments began monitoring culex mosquitoes June 1, according to the Jeffco health department. Culex mosquitoes are among the most common mosquitoes in the world and are primarily responsible for spreading West Nile virus.
According to the federal Centers for Disease Control, West Nile virus is a seasonal epidemic in North America that flares up in the summer and continues into the fall. Roughly 80 percent of people infected with West Nile virus will not develop symptoms. The other 20 percent develop fever, headache, body aches, nausea, vomiting and sometimes swollen lymph glands. They could also develop rashes on their chests, stomachs and backs. Symptoms will last for several days, but even healthy people have reported symptoms lasting several weeks.
In rare cases — about one in 150 — people develop severe symptoms, which include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. Symptoms in those cases also last several weeks, but the neurological effects may be permanent.
Bryant said people can take several steps to prevent mosquito breeding and the dangers of West Nile, including cleaning out gutters and other places around homes where there is standing water. Places like empty flowerpots, plastic swimming pools or old tires need to be drained, and water in birdbaths should be changed at least weekly but probably more often.
Other precautions include avoiding outdoor activities at dusk or dawn, when mosquitoes are most active; wearing loose-fitting long-sleeved shirts and pants, along with shoes and socks if you're outside during those hours; and using mosquito repellent containing DEET, picaridin or oil of lemon eucalyptus.
Also, avoid touching dead birds.
"This is not something to mess around with," Bryant said.
Additional information on the West Nile virus and prevention tips can be found at www.fightthebiteColorado.com. The website has tips for avoiding the virus and how to protect children and pets, among other topics. It also includes a link to the Centers for Disease Control's Web page on West Nile virus, which offers a national perspective.