HUNTINGTON — As the region nears its typical peak season for mosquito-borne illness, West Virginia’s public health officials are continuing to monitor for viruses in mosquito populations across the state.
Mosquitoes are most active from May through October, with the majority of mosquito-borne illnesses occurring in the warmest, wettest months.
The Cabell-Huntington Health Department tests mosquitoes caught in traps throughout the area — including 27 sites just in Cabell County — in conjunction with the West Virginia Office of Laboratory Studies. The department also will investigate any complaints of heavy mosquito activity.
Mosquitoes are screened for diseases like the West Nile Virus, La Crosse encephalitis and the Zika virus. There have so far been no cases of those diseases in West Virginia this year, according to data from the West Virginia Department of Health and Human Resources.
The West Nile virus, a relatively common disease, was found in several groups of mosquitoes in Cabell County last summer. Cabell County also confirmed cases in 2017 and 2015 in the mosquito population, and West Virginia’s only case of human-contracted West Nile for 2017, according to DHHR.
West Nile virus can cause symptoms like fever, headache, body ache, joint pain, vomiting, diarrhea or rashes, though the disease commonly presents no symptoms in an infected person. Individuals older than 60 are typically more affected.
In rare cases, the virus may develop into a more serious illness, like encephalitis or meningitis, which can lead to hospitalization or, in rare cases, death.
Neither La Crosse nor Zika was found in Cabell County over the past two years.
Compared to other states, West Virginia typically has a much lower incidence of mosquito-borne illnesses. In 2012 — a high outlier for West Nile — only 10 cases were confirmed in West Virginia, compared with 5,674 cases across the nation that year.
La Crosse is the most common mosquito-borne illness endemic in West Virginia, according to DHHR — with around 10 to 20 reported cases of La Crosse in West Virginia each year.
La Crosse causes inflammation of the brain (encephalitis) which causes nausea, headache, vomiting and in serious cases seizures, paralysis and permanent brain damage.
There have been four cases of dengue fever and one case of malaria reported in West Virginia this year, though all those cases are travel-related, according to DHHR. This is defined as West Virginia residents contracting the disease in countries where the diseases are more common and returning home.
Mosquito-borne illnesses cannot be spread by casual human-to-human contact.
Mosquito bites are largely avoidable, and the health department is encouraging residents to take precautions to avoid contracting the disease.
“Human cases of La Crosse encephalitis usually occur in areas with water-filled containers breeding mosquitoes,” said Forrest Wamsley, a registered sanitarian at the Cabell Huntington Health Department.
Eliminating standing water where mosquitoes breed, particularly around the home, is key to limiting the risk for mosquito bites. This includes emptying standing or stagnant water from old tires, pails, barrels, cans, bottles, wading pools, flower pots and other containers. Residents also can clean out clogged gutters and drill holes in the bottom of recycling containers.
Wearing long sleeves and pants outside also prevents mosquitoes from biting exposed skin. Insect repellents are also effective, specifically those that contains DEET, picaridin, IR3535 or oil of lemon eucalyptus on exposed skin and clothing when outdoors, the health department states.