A rare mosquito-borne virus has been confirmed in Claiborne County, putting East Tennessee residents on notice during the region’s busiest stretch of mosquito season. The case is classified as neuroinvasive, meaning the infection can affect the nervous system and become far more serious than a routine summer bug bite.
Federal health officials confirmed the case in a Claiborne County resident, and it is the only La Crosse virus infection reported in Tennessee so far this year, according to WVLT. The station reported that the Centers for Disease Control and Prevention had recorded only four human cases nationwide as of the latest update, with the others in Alabama, North Carolina and Ohio.
Why La Crosse Virus Is A Concern In Appalachia
La Crosse virus spreads through the bite of an infected mosquito, and most people who contract it have no symptoms or only mild, flu-like illness. The CDC explains that severe disease is most common in children under 16 and can include encephalitis, or inflammation of the brain.
The new case also fits a recent pattern in the region. In 2025, the Knox County Health Department reported two La Crosse cases, both involving children who were hospitalized before returning home, as reported by WVLT.
How East Tennessee Residents Can Reduce Their Risk
Local officials are urging residents to drain standing water from birdbaths, flower pots, clogged gutters and old tires, while also repairing window and door screens. The latest guidance also calls for EPA-approved repellents containing DEET, picaridin or oil of lemon eucalyptus, plus long sleeves and pants in wooded areas or during peak mosquito activity, according to the report.
Tennessee’s Department of Health says early symptoms can include fever, headache, nausea, vomiting, fatigue and lethargy. Severe cases may involve seizures, coma or paralysis, while fatal infections are rare; anyone who develops concerning symptoms after mosquito exposure should contact a health care provider, according to the Tennessee Department of Health.
The CDC’s 2026 La Crosse surveillance totals are preliminary and can lag behind information held by state and local health departments. The agency says the data are updated every one to two weeks during mosquito season, so the national and Tennessee counts could change as additional cases are reported.
