West Nile virus can be deadly, but the good news is that it is preventable. Taking several simple precautions to avoid mosquito bites greatly reduces the chances of exposure.

A 50-year-old Weld County woman developed West Nile virus fever on May 24, but never was hospitalized and is now recovering, according to the Colorado Department of Public Health and Environment.

The second case involved a 17-year-old male from Fort Collins who became ill on June 5. He was hospitalized briefly and is recovering.

West Nile virus is carried by culex tarsalis mosquitoes. Two years ago, Colorado led the nation in human West Nile cases and deaths, with 2,947 cases and 63 deaths. Last year, the numbers dropped to 291 cases and four deaths.

'It Is Preventable'

Humans are apparently most vulnerable during the first full season that West Nile hits an area, because neither birds, which are often hosts of the virus, nor humans have any immunity, epidemiologists say. The following years, enough birds have died or have built up immunity that the spread of the disease is diminished.

This year's wet spring and subsequent hot weather have brought a lot of mosquitoes to the Front Range, raising fears of a bad West Nile year.

But in Boulder County not a single mosquito with West Nile has been found in insect traps, spokeswoman Chana Goussetis said.

"We've had no human cases, no dead birds," Goussetis said. "We've all been waiting, with the rain and hot weather. There's plenty of mosquitoes, but no positives. We'll probably see it later in the season."

And that's the warning health officials want to instill in the public. Just because numbers are low today doesn't mean they'll be low a week or a month from now.

"The good news is that it is preventable," said Douglas H. Benevento, executive director of the Colorado Department of Public Health and Environment.

How to Avoid the Virus