Link to DEM Home Page Link to State of RI web site RIDEM graphical banner, showing land and water scene
Navigation button, HomeNavigation button, ProgramsNavigation button, TopicsNavigation button, MapsNavigation button, PublicationsNavigation button, NewsNavigation button, EventsNavigation button, SearchNavigation button, HelpNavigation button, Contact
Home > News > News Item


Mosquito Response Protocol

DOH's WNV Page

DOH's EEE Page
News Release
RI Department of Environmental Management
235 Promenade Street, Providence, RI 02908
(401) 222-2771 TDD/(401) 222-4462

For Release: June 25, 2007
Contact: Gail Mastrati 222-4700 ext. 2402
Stephanie Powell 222-4700 ext. 4418


PROVIDENCE - The Department of Environmental Management announces that test results from the first mosquitoes trapped this season are negative for both West Nile Virus and Eastern Equine Encephalitis. DEM staff collected the mosquitoes from 38 traps set statewide on June 5 and June 13 and separated them into 64 mosquito pools for testing by the RI Department of Health Laboratory. Results for all pools were received on Friday.

Test results from mosquitoes trapped last week are expected by the end of this week. 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.

Personal Protection Urged

Personal protection is still the first line of defense against mosquito-borne disease. 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, they are urged to get rid of anything in their yards that holds standing water, such as old tires, buckets, junk, and debris, and to make sure their gutters are clean so that they drain properly and that swimming pools are properly maintained. Mosquitoes breed in standing water. Just one cup of standing water can produce hundreds of mosquitoes.

Personal protection and larviciding are cornerstones of the state's mosquito response protocol, which has not substantially changed during the past six years. 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.

Testing of Birds Unnecessary

Since West Nile Virus and Eastern Equine Encephalitis are both firmly established throughout the state, it will not be necessary to test birds for those viruses as an "early warning." Residents can dispose of dead birds by double-bagging them and putting them in their household trash. There is no evidence that birds can transmit West Nile Virus to humans; mosquitoes that bite infected birds and then bite humans are the transmitters. However, as with any dead animal, avoid bare-handed contact of the carcass by using gloves or an inverted bag to place it in the double bag for disposal.

2006 Rhode Island Roundup

Last year, in Rhode Island, 10 mosquito pools tested positive for West Nile Virus, and three mosquito pools tested positive for EEE. There were no reported human cases in Rhode Island. However, in nearby Massachusetts, there were five human cases of EEE, including two deaths. More than 150 mosquito pools tested positive for EEE in that state. Connecticut had nine human cases of West Nile Virus, including one death.

The Viruses

EEE, a cyclical virus, while not nearly as common as West Nile Virus, 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.

West Nile Virus 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. West Nile Virus made its first appearance in the Western hemisphere, in the New York City area in 1999, and has since spread throughout the country. In 2006, more than 4,000 human cases of West Nile Virus were reported throughout the country, including 177 deaths.

For online information about mosquito-borne diseases, go to DEM's website,, and click on "Public Health Updates", or go to the HEALTH website,, and click on "E" (Eastern Equine Encephalitis) or "W" ((West Nile Virus)) under "Health Topics".


For General Information 222-6800 • After Hours Emergencies 222-3070 • Disclaimer