West Nile virus cases surface around Western Slope

MONTROSE — No human West Nile virus cases have been reported for Montrose and Delta counties this year but health officials urge people to remain vigilant about protecting themselves.

Mosquito-borne viruses are most prevalent from May to September, with the highest risk to humans occurring from August through early September, according to the Colorado Department of Public Health and Environment.

“The threat of West Nile is there,” said Richard Thompson, environmental health manager for Montrose County Health and Human Services. “We’ve not found it in the mosquito population, we’ve found it in the human population in Gunnison and Mesa Counties — on two sides of us.”

Thompson said the county has not found the number of mosquitoes it has in the past probably because of the cooler weather. West Nile virus has not been identified in any of the county’s mosquito samples. “I’m still getting people calling in and saying, ‘we’re finding a lot of mosquitoes,’” he said.

Montrose County had three cases of human West Nile Virus infections and Delta County had six cases in 2007; no deaths occurred in these cases, according to the CDPHE.

So far this year, Gunnison and Mesa counties each reported one human case of the virus, Thompson said. Other cases occurred on the Front Range, he said. Mesa County reported its first West Nile virus case Thursday. Published reports identified the victim as a man in his late 20s who contracted West Nile fever.

Although no human cases have been reported in Delta County, environmental health director Ken Nordstrom said people should continue taking safety precautions.

“We expect it to show up here soon,” Nordstrom said. “... We don’t want people to lower their guard. It’s important people maintain their diligence, use insect repellent and be careful.”

He said August is historically the peak of mosquito season. However, in more than 100 mosquito samples submitted beginning in June, Delta county has not identified any mosquitoes that are positive for the virus. Nordstrom said the cooler weather and monsoonal moisture flow probably has something to do with the county’s findings.

Officials have seen pretty large populations of mosquitoes in the county nonetheless.

“It’s important for people to drain out irrigation areas and standing water; empty out bird baths, flower containers and make sure small containers of water are dumped out on a weekly basis. Draining standing water is an important thing because that’s what mosquitoes like to breed in.”

Ponds that can’t be drained should be treated with larvicide, Nordstrom said.

West Nile virus, which is transmitted from mosquitoes to humans and animals, can cause paralysis, encephalitis (inflammation of the brain) and/or meningitis (inflammation of the brain’s lining).

According to Fight the Bite Colorado, most infections are mild and symptoms include fever, headache, body aches, and occasionally include skin rashes and swollen lymph nodes.

For further information from the Colorado Department of Public Health and Environment, call the Colorado West Nile virus hotline at 1(877) 462-2911 or visit the Web site: www.fightthebitecolorado.com

Contact Lisa Huynh via email at lisah@montrosepress.com