08 Sep 2015


West Nile Virus Active in Missouri

The Office of Veterinary Public Health (OVPH) would like to remind everyone that late summer/early fall is the time of year when most human cases of West Nile Virus (WNV) occur. West Nile Virus (WNV) is most commonly spread by bites from infected Culex species of mosquitoes. Mosquitoes can be active until the first hard frost of autumn. In addition to transmission of disease through insect bites, WNV can also be transmitted through transplants of infected organs and blood products. WNV can cause febrile illness, encephalitis, and/or meningitis.

The Missouri Department of Health and Senior Services (DHSS) has received reports of West Nile Virus activity in all parts of the state, including seven neuroinvasive human cases and four blood donors. Approximately 80% of people who become infected with West Nile Virus will not experience any symptoms of infection, and less than 1% will develop the more serious, neuroinvasive form.

Individuals who do develop symptoms of West Nile Virus illness may experience a sudden onset of fever that often includes headache, muscle pain and/or joint pain. Other commonly reported symptoms of illness include gastrointestinal tract symptoms and maculopapular rash. Serious illness can occur in people of any age. However, people over 60 years of age are at the greatest risk for severe disease. People with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants, are also at greater risk for serious illness. Fatigue and muscle weakness may linger for weeks or months following acute illness caused by West Nile Virus.

The best way to avoid this illness is to avoid mosquito bites. When going outdoors, using an insect repellent on the skin that contains DEET, picaridin, or another EPA-approved ingredient that is effective for mosquitoes can help prevent bites. Appropriate clothing, such as long pants and sleeves (when weather permits) can minimize exposed skin. Permethrin is a repellent that can be applied to clothing or gear that will be used outdoors. It is a long-lasting product that can withstand multiple washes before re-applying. Do not use permethrin directly on the skin.
Around the home, several precautions can be taken to reduce West Nile Virus risk, primarily removing standing water from yards. Mosquitoes that carry WNV prefer to breed in locations that have standing water, such as birdbaths, buckets, flower pots, tires, and pool covers. By emptying these items or changing the water weekly, the number of mosquitoes around homes can be reduced. To prevent mosquitoes from entering homes, it is recommended that residents use air conditioning if it is available. Screens should be installed and maintained on all windows and doors around the home to minimize mosquito entry.

West Nile Virus Fact Sheet

DHSS West Nile Virus

No comments