West Nile Virus threatens Montana
State and local public health officials are reminding Montanans to be aware of the risks of infection with West Nile virus (WNV) and to take steps to avoid mosquito bites. As the weather becomes warmer and drier in July, mosquitoes capable of transmitting WNV emerge.
Since the arrival of WNV in Montana in 2002, over 90 percent of cases in humans have been reported in August and September.
“The best way to prevent West Nile virus infection is to prevent mosquito bites,” said Department of Public Health and Human Services (DPHHS) Director Richard Opper. “The more time you spend outdoors, the more chance you have to be bitten by an infected mosquito. We encourage everyone to take precautions against West Nile while recreating outside this summer.”
Steps you can take to minimize the probability of infection include remembering the 5 D’s of West Nile Virus prevention:
DAWN & DUSK - When possible, avoid spending time outside at dawn and dusk.
DRESS - Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time or when mosquitoes are most active. Clothing should be light colored and made of tightly woven materials to keep mosquitoes away from the skin.
DRAIN - Reduce the amount of standing water in or near your property by draining and/or removing it. Mosquitoes may lay eggs in areas with standing water.
DEET - For additional protection from mosquitoes, use an insect repellent containing DEET (N,N-diethyl-m-toluamide) or picaridin (KBR 3023). Other insect repellents such as oil of lemon eucalyptus and IR3535 are also registered by the EPA but may be less effective than products containing DEET. It is important to follow the product guidelines when using insect repellant.
Infection by WNV develops in about 3 to 14 days after being bitten by a mosquito carrying the virus. While most people who become infected with WNV experience no symptoms, some individuals may develop a mild illness, called West Nile fever.
Symptoms include headache, muscle aches, and low grade fever. About 1 in 150 infected persons develop symptoms of encephalitis or meningitis. Symptoms of these diseases may include headache, rash, high fever, stiff neck, mental confusion, muscle weakness, tremors, convulsions, coma and paralysis. Individuals who develop any of these symptoms should see their health-care provider immediately. There are no medications to treat or vaccines to prevent WNV infection.
The number of reported West Nile Virus cases in Montana varies each year. In 2003 and 2007 over 200 cases were reported; however, in 2010 no cases were reported. There were 38 reported cases in Montana in 2013. “There are many factors that contribute to the impact of WNV on Montanans in any given year, so it is very important to take precautions, protect yourself from bites and eliminate breeding sites around your home,” said Joel Merriman, of DPHHS Communicable Disease Epidemiology Section.
For more information about WNV protection and detection efforts, contact your local health department, or the Department of Public Health and Human Services, 444-0273 or the DPHHS website at: www.dphhs.mt.gov