Hordes of blood-sucking mosquitoes are just waiting to take a bite out of your summer fun, but the good news is that, so far this year, none of those mosquitoes have tested positive for West Nile Virus or Eastern Equine Encephalitis in Rhode Island – at least not yet.
The Department of Environmental Management (DEM) said earlier this week that test results from all 125 mosquito pools, or samples, from 21 traps set statewide during the week of June 17 were negative for both West Nile Virus and Eastern Equine Encephalitis. In addition, the remaining 32 mosquito pools from seven traps set during the week of June 10 were confirmed negative for WNV and EEE.
But things could change.
“Usually with these diseases we don’t start seeing issues until late summer,” says Dr. Al Gettman, a medical entomologist and DEM mosquito abatement coordinator.
Last year in Rhode Island, six pools of mosquitoes tested positive for Eastern Equine Encephalitis and five pools tested positive for West Nile Virus. The first positive test came back on July 9 of last year and the rest were later in the summer.
“So, it’s still early and we could see some pools testing positive later on,” Gettman said.
Mosquitoes are trapped every week statewide by DEM staff and tested at the Rhode Island Department of Health laboratory in Providence. DEM will normally report mosquito test results once a week on a routine basis, with additional reports as necessary. Positive mosquito test results will generally trigger additional trapping to assess risk.
This summer, Gettman and other mosquito experts are seeing a huge increase in mosquitoes due to the more than nine inches of rainfall the state had in June – rain that provided prime breeding grounds for mosquitoes.
"This is the most mosquitoes I’ve seen in 21 years," Gettman said. “We’ve got this big crop of mosquitoes and that’s because of the rain we had in June.”
Throughout the mosquito season, people can protect themselves by eliminating mosquito breeding grounds and avoiding mosquito bites. Personal protection is the first line of defense against mosquitoes that can carry West Nile Virus and EEE and is by far the most effective way of avoiding infection.
"We see these health threats every year, and a few simple actions can help keep Rhode Islanders safe from tick and mosquito-borne illnesses, such as Lyme disease, West Nile Virus and Eastern Equine Encephalitis, and from rabies exposure,” said Department of Health Director Michael Fine.
“As part of their normal seasonal routine, Rhode Islanders can protect themselves from exposure to West Nile Virus and EEE by avoiding mosquito bites and eliminating mosquito breeding grounds," said DEM Director Janet Coit. "At this time of year, residents are encouraged to remove anything in their yard that holds standing water and to make sure their gutters are clean so that they drain properly. Mosquitoes breed in standing water and just one cup of standing water can produce hundreds of mosquitoes."
You can avoid mosquito bites by using screens on windows and doors, covering up at dawn and dusk, and putting mosquito netting over playpens and baby carriages when they are outside. Also, use mosquito repellent, but with no more than 30 percent DEET.
Personal protection and larviciding are cornerstones of the state's mosquito response protocol. Aerial or ground spraying will be recommended only when a team of mosquito-control experts determines that the public is at substantial risk of contact by infected mosquitoes.
DEM distributed the "Four Star" larvicide product, which is a briquette that releases environmentally-benign bacteria over a 90-day period, to municipalities on June 4 at East Farm at the University of Rhode Island for treating all public area catch basins. Catch basins are considered prime breeding areas of mosquitoes in both urban and suburban settings, and the use of larvicide is the best way for communities to reduce mosquito numbers and risk.
Some communities will also be applying Bti "donuts" to standing water bodies and small areas that are hard to treat. Both products are specific to mosquito larvae and have excellent environmental track records.
Because horses are susceptible to West Nile Virus and EEE, Rhode Island horse owners should vaccinate their horses early in the season and take measures to control and prevent mosquito exposure.
Ticks also love warm weather and a moist climate .The risk of being bitten by a deer tick infected with Lyme disease is greatest in the summer months of June and July when the nymph stage is active. The risk is also high in the fall, when adults are active. If you live in or have visited an area with a high incidence of ticks, it is important to know the symptoms of Lyme disease, which include headache, flu-like symptoms, a spreading "bull's-eye" rash from the tick bite, and swelling and pain in the joints.
Lyme disease symptoms mimic many other diseases. About 80 percent of Lyme disease victims develop a rash within two days to four weeks. If untreated, more severe symptoms may develop - sometimes months to years later.
(Follow Joseph Fitzgerald on Twitter @jofitz7)