Mosquito with West Nile Virus trapped in MC

By Amorette Allison
Star Staff Writer

West Nile Virus has been detected in a mosquito trapped at the Fort Keogh Livestock and Range Research Laboratory, the first mosquito found to be carrying the disease in Custer County this year.
The find was announced this week by Megan Van Emon, a Montana State Universtiy extension employee who conducts the local testing. A mosquito also tested positive in Prairie County this year.
Van Emon said she started catching mosquitoes at the end of June. The batch that tested positive were sent for testing in the last week of July. Van Emon says finding positive tests this time of year is “pretty normal.”
No human or animal cases of West Nile were recorded in the county this year or last year, but there were four cases in adjacent Dawson County. According to the federal Centers for Disease Control, about 70-80 percent of people who become infected with West Nile virus do not develop symptoms.
According to a news release from Montana State University entomologists Greg Johnson and Marni Rolston, the highest densities of the species of mosquito that carries West Nile Virus are “found in areas associated with irrigated agriculture, prairie wetlands and riparian areas adjacent to river drainages.”
Cindia Ellis of oneHealth says that the best thing people can do is take precautions to prevent getting bitten by a mosquito in the first place.
Ellis says people should avoid being out at dawn and dusk, when mosquitoes are most active, and should wear long-sleeves and long pants that are “light colored and of tightly woven fabric.” Socks and shoes are also recommended as well as mosquito repellant.
Insect repellants recommended included DEET (tradename OFF), picaridin (Cutters Advanced), oil of lemon eucalyptus (Repel Lemon Eucalyptus) and IR3535 (Avon Skin-So-Soft Bug Guard.)
Also keep window screens in good repair and make sure there is no standing water for mosquitoes to breed in. Even a little water in the drain tray under a flowerpot, said Ellis, can provide a place for mosquitoes to breed. Draining wading pools after use and making sure there is no standing water in things like tire swings also help reduce mosquito populations in general.
According to Ellis most infected people develop no symptoms, some have flu-like symptoms for three to six days, and a few can develop “severe symptoms including high fever, headaches, numbness and paralysis.” In rare cases, West Nile Virus can be fatal.
There is no treatment for the disease and more severe neurological symptoms “can last several weeks,” according to Ellis.
West Nile is only transmitted by being bitten by an infected mosquito. It can’t be passed from person-to-person contact or animal-to person casual contact. However, the Centers for Disease Control recommend avoiding bare-handed contact when handling any dead animal. If you are disposing of a dead bird, use gloves or double plastic bags to place the carcass in a garbage can
While there is no vaccine for humans, there is an effective equine vaccine. There are also insect repellants for horses. However, repellants have to be applied frequently, depending on the product, throughout mosquito season.
For horses, vaccination is highly recommended by experts, even this late in the summer. There is no specific treatment for infected animals so prevention is again the key. As with people, some horses recover quickly and other infections are fatal.
(Contact Amorette Allison at 406-234-0450 or