Mosquito-borne illness is circulating throughout Tennessee and state health officials are urging the public to take preventive steps to avoid mosquito-borne diseases.

This comes after reports of two West Nile virus (WNV) fatalities in Shelby County.
“We all know mosquitoes aren’t just a nuisance. Last year 30 Tennesseans were infected with West Nile virus and sadly, we saw two recent deaths in Shelby County,” said TDH Commissioner John Dreyzehner, MD, MPH. “Most but not all healthy people can fight off West Nile virus infection, but some get seriously ill with major consequences like severe pain, long-term or permanent nerve or brain damage and even death. This is a critical time of year and it’s up to all of us to do what we can to keep ourselves and others safe from mosquito bites.”
In most years, the majority of human West Nile cases in Tennessee occur in August and September. All Tennesseans are advised to use mosquito protection for the remainder of the summer and early fall.
West Nile Virus (WNV) was first isolated in a woman in the West Nile district of Uganda in 1937. In 1999 a WNV circulating in Israel and Tunisia was imported in New York and is now ever present in the US annually.
WNV has been detected in dozens of mosquito species.
Up to 80 percent of people who become infected with West Nile virus do not develop any symptoms.
About 20% of people who become infected with WNV will develop West Nile fever. Symptoms include fever, headache, tiredness, and body aches, nausea, vomiting, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands.
Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). Of this number, about 10 percent will die.
In addition, health officials have seen six cases of La Crosse encephalitis in children so far this year.
La Crosse encephalitis virus (LACV) is transmitted to humans by the bite of an infected mosquito. Most cases of LACV disease occur in the upper Midwestern and mid-Atlantic and southeastern states.
It was reported first in 1963 in LaCrosse, Wisconsin and the vector is thought to be a specific type of woodland mosquito (Aedes triseriatus) called the tree-hole mosquito.
Among people who become ill, initial symptoms include fever, headache, nausea, vomiting, and tiredness. Some of those who become ill develop severe neuroinvasive disease (disease that affects the nervous system).
In rare cases, long-term disability or death can result from La Crosse encephalitis.
The Tennessee Department of Health encourages everyone to follow these precautions to avoid mosquito bites:
- Use insect repellants such as DEET, Picaridin, oil of lemon eucalyptus or IR3535 on your skin, following all label recommendations for use. Pay particular attention to recommendations for use on children, and never apply any of these products around the mouth or eyes at any age. Consult your health care provider if you have questions.
- Reduce mosquito populations around your home. Mosquitoes can breed in any place that holds water, including clogged drains or gutters, watering cans and empty bottles.
- Use products containing permethrin, a highly effective insecticide, for clothing, shoes, bed nets and camping gear. Permethrin-treated clothing repels and kills ticks, mosquitoes and other pests and retains this effect after repeated laundering. Some commercial products are available pretreated with permethrin. As a caution, however, it is not to be used directly on skin.
- Wear ’long, loose and light’ clothing to help prevent bites through fabric. It’s best to wear long-sleeved shirts and long pants. Tuck your pants into your socks and your shirt into your pants. Light-colored clothes are less attractive to many insects and may allow you to spot them more easily.
Related:
- Plague confirmed in Wyoming cat
- STDs in the US: ‘An additional $70 million annually is needed to kickstart an effective response’
- Ending cholera in Africa: Health minister’s pledge
- Syphilis cases up nearly 300 percent in Pennsylvania in past decade
- Measles exposure alert for Lancaster County
- Over 1000 infected in new Nigeria diarrhea outbreak
- Florida cow is country’s 6th BSE case