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Tuesday, June 30, 2015

So far, so good

First round of testing of mosquitos negative for summer bug-borne diseases

PROVIDENCE - The Department of Environmental Management announces test results from the first mosquitoes trapped this season. 

All of the 64 mosquito pools collected by DEM staff from 20 traps set statewide on June 15 have been confirmed negative for both West Nile Virus (WNV) and Eastern Equine Encephalitis (EEE). 

Test results are pending at the RI Department of Health (HEALTH) Laboratory for 134 mosquito pools collected from 23 traps set on June 22.

DEM will normally report mosquito test results once a week on a routine basis from late June through September, with additional reports as necessary. Positive mosquito test results will generally trigger additional trapping to assess risk.

With WNV and EEE established throughout the state, DEM and HEALTH are reminding Rhode Islanders that personal protection is the first line of defense against mosquito-borne diseases. 

Residents should, as part of their normal seasonal routine, protect themselves from exposure to West Nile Virus and EEE by avoiding mosquito bites and eliminating mosquito breeding grounds.


At this time of year, Rhode Islanders are urged to do the following to prevent mosquito bites:
  • Get rid of anything in your yard that holds standing water, such as old tires, buckets, junk, and debris.
  • Make sure your gutters are clean so that they drain properly. Mosquitoes breed in standing water. (Just one cup of standing water can produce hundreds of mosquitoes.)
  • Use bug spray with no more than 20% DEET when you are outside. Bug spray should not be used on infants.
  • Avoid outdoor activity at dawn and at dusk when mosquitoes are most active.
  • Use insect netting over strollers and playpens outside.
  • Repair holes in window screens so help keep mosquitoes outside.
  • Help family, friends, and neighbors do the same.

Personal protection and larviciding are cornerstones of the state's mosquito response protocol. Aerial or ground spraying will be recommended only when the Mosquito Advisory Board 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 2 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.

Tips for Horse Owners
  • Horses are susceptible to West Nile Virus and EEE. Therefore, Rhode Island horse owners should vaccinate their horses early in the season and take measures to control and prevent mosquito exposure. Those controls should include the following:
  • Remove or cover all areas where standing water can collect.
  • Avoid turning animals outside at dawn, dusk and during the night when mosquitoes are most active.
  • Insect proof facilities where possible.
  • Use approved repellants frequently.
  • Monitor animals for symptoms of fever, neurological signs (such as stumbling and incoordination, depression, loss of appetite, inability to stand up) and report all suspicious cases to a veterinarian immediately. 
If you are unsure if your horse is properly vaccinated you should consult with your veterinarian.


2014 Rhode Island Roundup

Last year in Rhode Island, WNV was detected in two mosquito samples, both of which were collected in South Kingstown (right near Charlestown's town line). EEE was not detected in mosquitoes trapped in Rhode Island last year. Mosquitoes were tested at the Department of Health Laboratory in Providence.

The Viruses

EEE, a cyclical virus, while not nearly as common as WNV, has a higher fatality rate. It is a viral disease contracted through the bite of an infected mosquito. In most years, the virus is limited to native bird populations and bird-biting mosquitoes, but occasionally the virus can be transmitted to humans and domestic animals. EEE virus affects the brain with symptoms that appear 5 to 15 days after being bitten by an infected mosquito. Symptoms may include high fever, headache, stiff neck and decreased consciousness. Up to 50 percent of cases may result in fatality. Individuals with symptoms suggestive of EEE should contact their physician immediately.

WNV is also a mosquito-transmitted, viral disease that causes encephalitis. However, mortality rates are much lower than those of EEE. Most people bitten by WNV-infected mosquitoes do not get sick. However, the elderly and people with weakened immune systems are more prone to infections. Symptoms begin 3-15 days after the bite from an infected mosquito. Symptoms may include fever, headache, nausea, rash, stiff neck, muscle weakness, and disorientation. Of cases with serious symptoms, up to 15 percent may result in fatality. WNV made its first appearance in the Western hemisphere, in the New York City area in 1999, and has since spread throughout the country.

Visit HEALTH's website for additional prevention tips and for Rhode Island-specific data.