State Announces Additional West Nile Virus Findings
The mosquito samples testing positive for WNV were collected in North Kingstown, Tiverton, and South Kingstown.
These results are from 102 samples collected from 23 traps set statewide by DEM on August 27. All other samples tested negative for Eastern Equine Encephalitis (EEE) virus, WNV, or Jamestown Canyon Virus (JCV).
Last month, DEM, RIDOH, and the Mosquito Borne Disease Advisory Group (MDAG) they convene recommended that members of the public, schools, and communities consider “smart-scheduling" of outdoor activities during peak mosquito activity hours to help minimize the risk of mosquito bites.
Last week, DEM conducted an aerial application of mosquito larvicide across 3,000 acres of Chapman Swamp in Westerly and Great Swamp in South Kingstown to reduce mosquito populations and related disease risk.
As mosquito season continues, the MDAG will continue to evaluate the risk level statewide and will provide updates if any further mosquito control measures are planned. DEM and RIDOH continue to urge Rhode Islanders to protect themselves and their loved ones from mosquito bites and the diseases they carry, including EEE virus and WNV.
RIDOH and DEM are issuing a heightened public health warning that it is a particularly active mosquito season in Southern New England and that WNV is likely present in mosquitoes statewide.
Previously this season, Rhode Island has announced 17 EEE virus findings in mosquito samples, six WNV findings, and one probable human case of WNV. Testing indicates a significant risk in Washington County and an elevated risk level throughout Rhode Island.
The State of Connecticut has announced 46 EEE virus findings, 275 WNV findings, one JCV finding, one human case of WNV, and an animal case of EEE virus in a deer, and the Commonwealth of Massachusetts has announced 291 WNV findings, 88 EEE findings, two human cases of EEE virus, two animal cases of EEE virus, and six human cases of WNV.
It is notable that EEE virus and WNV have
been detected in several Massachusetts and Connecticut towns bordering Rhode
Island, indicating a higher risk in bordering Rhode Island communities.
WNV is the leading cause of mosquito-borne disease in the continental United States and is much more prevalent than EEE virus. Cases of WNV occur during mosquito season, which starts in the summer and continues through fall.
There are no vaccines to prevent or medications to treat WNV in people.
Fortunately, most people infected with WNV do not feel sick. About one in five people who are infected develop a fever and other symptoms. About one out of 150 infected people develop a serious, sometimes fatal, illness. For more information about WNV, please visit www.health.ri.gov/wnv.
Although extremely rare in humans, EEE virus is very serious
and has a much higher human mortality rate than WNV. Approximately 30% of
people with EEE virus die, and many survivors have ongoing neurological
problems. Unlike WNV, which is prevalent in Rhode Island every year, EEE virus
risk is variable, changing from year to year. With continued trapping and
testing, DEM and RIDOH will be able to assess the EEE virus risk level this
mosquito season. For more information on EEE virus and ways to prevent it, please
visit www.health.ri.gov/eee.
EEE virus and WNV are typically present in wild bird
populations. Birds are reservoirs of the diseases and mosquitoes transmit these
viruses among birds. During an active mosquito season, the viruses are
amplified in the environment with each generation of mosquitoes. At a certain
point, several mosquito species that bite both birds and mammals serve as a
bridge between infected birds and uninfected mammals. Most bridge species
are within the Aedes, Coquillettidia, and Culex genera.
Mosquito Control:
Residents can help control mosquitoes by removing backyard
mosquito breeding grounds. The Asian
Tiger Mosquito has become prevalent in Rhode Island urban
environments, and it is expected to be common again this season. It is notable
as a daytime biter encountered in shaded backyards. It has a striking black and
white pattern evident to the naked eye. It develops from eggs laid in
artificial containers, so residents are urged to remove standing water from
containers such as buckets, pots, wheelbarrows, boats, and pools. Clogged rain
gutters and puddles formed on tarps also can support the larvae of this species.
The Asian tiger mosquito is known to transmit several diseases, including WNV.
In addition to considering smart-scheduling, Rhode Islanders
should take the following measures to protect themselves from mosquito
bites and to help minimize mosquito breeding:
Protect yourself!
- Put
screens on windows and doors. Fix screens that are loose or have holes.
- Consider
rescheduling outdoor activities that occur during the evening or early
morning at sunrise and sundown (when mosquitoes carrying the EEE virus are
most active). If you must be outside, wear long-sleeved shirts and pants
and use bug spray.
- Use EPA-approved bug spray with one of the following
active ingredients: DEET (20-30%
strength), picaridin, IR3535, and oil of lemon eucalyptus or
paramenthane. Always read the label and follow all directions and
precautions.
- Do not
use bug spray with DEET on infants under two months of age. Check the
product label to find the concentration of DEET in a product. The American
Academy of Pediatrics recommends that repellents contain no more than 30%
DEET when used on children. Children should be careful not to rub their
eyes after bug spray has been applied on their skin. Wash children’s hands
with soap and water to remove any bug spray when they return indoors.
- Put
mosquito netting over playpens and baby carriages.
Remove mosquito breeding grounds!
- Remove
items around your house and yard that collect water. Just one cup of water
can produce hundreds of mosquitoes; an unused tire containing water can
produce thousands of mosquitoes.
- Clean
your gutters and downspouts so that they can drain properly.
- Remove
any water from unused swimming pools, wading pools, boats, planters, trash
and recycling bins, tires, and anything else that collects water, and
cover them.
- Remove
or treat any shallow water that can accumulate on top of a pool cover.
Larvicide treatments, such as Mosquito
Dunks can be applied to kill immature mosquitoes. This
environmentally friendly product is available at many hardware and garden
stores and online.
- Clean
and change water in birdbaths at least once a week.
Best practices for horse owners!
Horses are particularly susceptible to WNV and EEE virus.
Horse owners are advised to vaccinate their animals early in the season and
practice the following:
- Remove
or cover areas where standing water can collect.
- Avoid
putting animals outside at dawn, dusk, or during the night when mosquitoes
are most active.
- Insect-proof
facilities where possible and use approved repellents frequently.
- Monitor
animals for signs of fever and/or neurological signs (such as stumbling,
moodiness, loss of appetite) and report all suspicious cases to a
veterinarian immediately. If you are unsure if your horse is properly
vaccinated, consult your veterinarian.
Visit health.ri.gov/mosquito for
additional mosquito prevention tips, videos, and local data. DEM traps
mosquitoes weekly and tests them at the RIDOH State Health Laboratories. From
June through September, DEM issues advisories on test results, with additional
reports as necessary. Typically, positive test results trigger additional
trapping to assess risk.
For more information on DEM programs and initiatives,
visit www.dem.ri.gov.
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