MARTINSBURG, W.Va. — Knowing full well what to expect, Hayley Bush wrinkles up her nose and takes a slight step backward as she opens up a plastic bucket containing a special brew – one that’s specifically designed to attract mosquitoes.
While there are only three ingredients – water, brewers’ yeast and some grass clippings – the fermenting liquid usually packs a powerful punch, and today is no different when Bush inspects a net that’s part of this specially-designed trap aimed at luring mosquitoes flying near a catchment pond.
“It’s looking pretty lively in there,” she said, pausing momentarily to unhook the cloth compartment that will soon be frozen so any mosquito remains can be sent to Charleston for laboratory testing.
It’s all part of a state-funded initiative – the West Virginia Mosquito Surveillance Program – aimed at collecting timely data on mosquito populations in the state, especially areas where more infected mosquitoes are located, said Jennifer Hutson, sanitarion supervisor with the Berkeley County Health Department who is overseeing the seasonal program that began in June and runs through August.
During that time, Bush has not only set 18 traps in Berkeley, Jefferson and Morgan counties, but also routinely checks them and processes the mosquitoes for examination by state entomologist Eric Dotseth.
They are located in both woodland and wetland areas, because the goal is to get a broad sample so health officials – both county and state – can get a better idea if mosquitoes in the area are carrying any of four types of encephalitis, including La Crosse, West Nile, Eastern Equine and St. Louis, Hutson said.
Encephalitis (inflammation of the brain) can be potentially life-threatening. Symptoms – which generally begin to surface one to two weeks after a person is bitten by an infected mosquito – can include fever, headache, myalgia, meningitis and neurologic dysfunction, she said.
There’s good news, however, because in 2014 there were only seven cases of mosquito-borne diseases reported in West Virginia, including two La Crosse encephalitis (one probable, the other was a confirmed case). During that same time, no West Nile Virus cases were reported, according to state data.
However, it is important for state public health officials to keep up with what’s happening in this area so citizens can be warned about any potential problem, Hutson said.
For example, La Crosse encephalitis has historically been the “mosquito-borne disease of most concern in West Virginia, with up to 40 human cases reported in previous years,” according to a state Bureau for Public Health fact sheet.
Last year’s research revealed that mosquitoes infected with La Crosse encephalitis were active in three of the 16 counties where those samples were tested.
Four of the 761 mosquito pools were infected with this type of encephalitis, including two in Cabell County, one from Wayne County and an additional one in Wood County. However, this is the “first record of La Crosse-infected mosquitoes in Wood County,” the fact sheet states.
Ironically, the number of “imported” mosquito-borne disease cases was higher during this same time than locally-acquired infections, it continues, explaining that those five cases account for 71.4 percent of the state’s total number.
“Chikungunya (which typically causes fever combined with arthritis-like joint pain) made its way to West Virginia in June 2014, and again in October 2014. Both cases reported travel to the Caribbean,” the fact sheet continued.
While the state’s overall incident rate of mosquito-borne disease infections was considered “very low” in 2014, public health officials welcome the opportunity to educate people about how to avoid getting bitten in the first place, Hutson said.
“People should know that mosquitoes are generally most active between dusk and dawn. We also recommend they wear protective clothing, such as long sleeves and pants, but that can be difficult when the weather is hot,” she said.
Experts also recommend using an insect repellent – one containing DEET, picardin, IR3535 or oil of lemon eucalyptus – on exposed skin and clothing when outdoors.
– Staff writer Jenni Vincent can be reached at 304-263-8931, ext. 131.