What to know about La Crosse encephalitis
Mosquito-borne virus mainly affects children
Western North Carolina is known as a “hotspot” for La Crosse encephalitis, a disease carried in mosquitoes that mainly affects children, according to a WCU mosquito expert.
Western Carolina University sent out a news release July 6 warning folks that La Crosse encephalitis is the most common mosquito-borne disease in North Carolina — impacting children the most.
“The risk for malaria in our area is low,” said Brian Byrd in the news release. Byrd is a professor of environmental health sciences and supervisor of the Mosquito and Vector-Borne Infectious Disease Facility in the School of Health Sciences at Western Carolina University.
Byrd warned that “La Crosse encephalitis is the most common mosquito-borne disease in North Carolina and predominately affects children in WNC counties, so it is important to remember the three ‘ Ds’ of mosquito protection: ‘dress, drain and defend.’”
What is La Crosse and how does it turn into encephalitis?
● Most people infected with La Crosse (LAC) virus don’t have symptoms, but the incubation period can range from five to 15 days, according to the CDC.
● If symptoms do show up, they normally last two to three days and include headache, nausea, vomiting, fatigue and lethargy.
● LAC virus can cause an infection to the brain, which is encephalitis, and it is severe.
● Symptoms of encephalitis can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, seizures, muscle weakness, vision loss, numbness and paralysis.
● This is commonly seen in children younger than 16.
● Most patients will recover, though death does occur in less than 1% of cases.
“Lacrosse virus is the pathogen that’s the virus that causes disease. Encephalitis is the swelling of the brain and in some cases, the infection from the virus can lead to encephalitis,” Byrd told the Citizen Times on July
6.
“Over the past 20 years In North Carolina, we’ve had an average of between 15 and 17 cases of encephalitis. But what’s really interesting is that these cases represent what’s called the tip of the iceberg. For every case, every one of those 15 to 17 cases in Western North Carolina or in the state there’s probably somewhere between 100 to 250 people getting infected for each one of those cases.”
Cases now and then
According to the CDC, there have been no human disease cases for LAC as of June 27 of this year. The CDC has been tracking numbers since 2003. The highest number of cases was 130 in the United States in 2011 and the lowest number of cases was in 2022 with only 22 cases in the United States. From 2003 to 2022 there have been 329 reported cases in North Carolina — making it the second highest state in number of cases behind Ohio, which had 404 cases. Buncombe County reported 98 cases from 2003 to 2022, making it the county with the highest number of reported cases in WNC.
There have been 15 deaths in the U.S. since 2003, but there hasn’t been a reported death since 2014, according to the CDC data.
Advice from an expert
“The risk is higher here than in other parts of the state. We are kind of a hotspot if you will, from a national perspective, and there are simple things you can do to help reduce your risk,” Byrd said on July 6.
Avoid mosquito bites by dressing to
● cover skin.
Use EPA and CDC-approved repel
● lents.
If there’s standing water do your
● best to tip and toss it and reduce the risk of mosquitos around your house.
Why Western North Carolina?
Byrd said that 80% of the cases in the United States occur in WNC, Ohio, Eastern Tennessee, and West Virginia — most of these cases have been in Appalachia because of the abundance of hardwood trees.
The mosquito that transmits this virus is called the Eastern treehole mosquito, according to Byrd.
McKenna Leavens is the education reporter for the Asheville Citizen Times, part of the USA Today Network. Email her at mleavens@ citizentimes.com or follow her on Twitter @LeavensMcKenna. Please support this type of journalism with a subscription to the Citizen Times .