By Mckenzie Moore
West Nile Virus is a mosquito-borne virus that can spread to both humans and animals. It is transmitted when a mosquito bites an infected bird, then bites a human or animal that can contract the virus. West Nile first appeared in Delta County in 2003, and now circulates through the area. According to the Colorado State University extension, most cases of West Nile are contracted in July, August and September.
Last year, Delta County had the highest number of West Nile cases in the state, at 33 cases and two deaths. Delta County Environmental Health Director Ken Nordstrom encourages the community to be aware of the West Nile virus and how to prevent it.
“Throughout the years, West Nile Virus changes in numbers,” Nordstrom said. “We have a variation every year of how many cases we have. It seems to cycle, and it is very hard to predict what the season will produce as far as West Nile and how prevalent it is within the county.”
West Nile is primarily transmitted through mosquito bites, so the best way to avoid the virus is to avoid getting bitten. Delta County Environmental Health encourages people to remember the four “Ds” to help reduce the likelihood of mosquito bites: drain any standing water around your house or property (including irrigation and containers), use insect repellent containing DEET, avoid outdoor activities at dawn and dusk (when mosquitoes are most active) and dress in long sleeves and light colored clothing.
The virus is also prevalent in horses. Vaccines and insecticides are available for horses and should be discussed with your veterinarian. Other measures can be taken to protect other animals as well, such as using pet-safe insecticides and avoiding letting pets out at dusk and dawn and eliminating standing water.
In Delta County, surveillance for West Nile began last week, but results from the state laboratory have not yet been received.
“We have started mosquito trapping, and that’s our main surveillance tool,” Nordstrom said. “Delta County Mosquito Control District 1 traps mosquitoes every week, and we take those mosquitoes — the ones that carry and vector the disease — we send those to the state lab for testing and from that we can tell how much of the virus is out there, what the prevalence of the West Nile virus is.”
Mosquitoes carrying West Nile are more prevalent in lower elevations, while areas at high elevations will likely have far less of a population.
“The mosquitoes that carry West Nile virus are not very prevalent and you usually can’t find them above 9000 feet. So our mountain communities don’t have the virus, it’s mostly down in our irrigated valleys,” Nordstrom said.
According to the Delta County Health Department, only about 20 percent of people infected with West Nile show symptoms, and they are typically mild and flu-like. Less than one percent of people will get seriously ill. Symptoms of West Nile include a fever of 101 degrees or more, aches and pains, flu-like symptoms, headaches, eye pain, fatigue and confusion.
“If [symptoms] are severe enough, they need to go see their doctor,” Nordstrom said. “Most people that are infected don’t have severe forms, but they need to rest, limit their activities.”
The Delta County Mosquito Control District and North Fork Mosquito Control District will be analyzing and mitigating mosquito populations through surveillance and spraying. The Town of Cedaredge has also contracted a mosquito control company to control the population there as well. However, individuals should still take precautions to protect themselves during West Nile season.