Mosquito-borne disease update

Maine CDC has confirmed the presence of Eastern Equine Encephalitis (EEE) in more than 20 mosquito pools and has reported the death of a pheasant and two horses from EEE. In addition, one mosquito pool has tested positive for West Nile virus (WNV), the first WNV positive this year. More information is available in the press release at http://go.usa.gov/Dn9R

Maine CDC will update information on mosquito-borne disease surveillance in the state every Monday through September at http://go.usa.gov/jt6R

EEE and WNV are viruses transmitted through the bite of an infected mosquito. Maine CDC recommends the following preventative measures to protect against mosquito-borne illnesses:

• Use an Environmental Protection Agency-approved repellent when outdoors, especially around dawn and dusk. Always follow the instructions on the product’s label;
• Wear protective clothing when outdoors, including long-sleeved shirts, pants and socks;
• Keep window and door screens down to keep mosquitoes out of the home;
• Limit time outdoors at dawn and dusk when many species of mosquitoes are most active;
• Remove containers holding water in and around the home, as water can attract mosquitoes.

Information on pesticides and repellents is available at the Maine Board of Pesticides Control website at: http://go.usa.gov/jt6F

Mosquito-borne disease

Maine CDC has confirmed the presence of Eastern Equine Encephalitis (EEE) in two mosquito pools from York County.

EEE is a virus that is transmitted through the bite of an infected mosquito. It can cause serious illness in humans; large animals, like horses; and some species of birds. Maine confirmed EEE in a flock of pheasants during 2012 and experienced unprecedented EEE activity during 2009 with multiple animals and mosquito pools testing positive for the virus.

Regionally, all of our surrounding states have also identified EEE in 2013, including mosquito pools in New Hampshire, Vermont, and Massachusetts. Two horses have tested positive for EEE in Massachusetts as well.

Maine CDC recommends the following preventative measures to protect against EEE and other mosquito-borne illnesses:

• Use an Environmental Protection Agency-approved repellent when outdoors, especially around dawn and dusk. Always follow the instructions on the product’s label;
• Wear protective clothing when outdoors, including long-sleeved shirts, pants and socks;
• Keep window and door screens down to keep mosquitoes out of the home;
• Limit time outdoors at dawn and dusk when many species of mosquitoes are most active;
• Remove containers holding water in and around the home, as water can attract mosquitoes.

Maine's Health and Environmental Laboratory (HETL) routinely performs testing for EEE and West Nile virus (WNV) in mosquitoes, large animals and humans. Maine stopped testing individual dead birds for mosquito-borne illnesses in 2006 and no longer uses them as an indicator for disease.

Maine CDC will continue to update information on mosquito-borne disease surveillance in the state every Monday from May through September at http://go.usa.gov/jt6R

Information on pesticides and repellents is available at the Maine Board of Pesticides Control website at: http://go.usa.gov/jt6F

Know how to protect yourself from West Nile and EEE

Arboviral diseases, including Eastern equine encephalitis (EEE) and West Nile virus (WNV), are very serious infections that are transmitted by the bite of an infected mosquito. Although rare, these diseases have the potential to be severe and even fatal.


On Aug. 17, a mosquito pool (a collection which contains between 1-50 mosquitoes) tested positive for WNV at Maine’s Health and Environmental Testing Laboratory. The pool of mosquitoes was collected Aug. 1 in the town of Lebanon, as described in this health alert. Since then, a second mosquito pool from Cumberland County tested positive.

This is the earliest WNV has been identified in mosquitoes in Maine. The last time WNV was identified in Maine was from a mosquito pool in 2010. There has been a significant increase in arboviral activity in the last month.

Maine CDC recommends the following preventative measures to protect against mosquitoborne illnesses:

Control what you can. Improve your odds of avoiding mosquito spread viruses by using a repellent on exposed skin and clothes while outdoors. Wear protective clothing when outdoors, including long-sleeved shirts, pants, and socks. Use screens on your windows and doors to keep mosquitoes out of your home, and remove standing water from artificial water-holding containers in and around the house.


Insect Repellent: It keeps you from being what’s for dinner.

There are always excuses for not using repellent— forgot it, didn't want to go back and get it, it doesn't smell good, it's not in the budget, or "mosquitoes don't bite me"…

Think of repellent as you would an important article of clothing, and increase your chances of avoiding weeks (or even months) of aches and fatigue that come with West Nile fever, dengue fever, or any number of other mosquito borne diseases. More severe problems are possible. Being hospitalized with swelling of the brain, or even worse, are possibilities from many of these diseases.


What repellent should I use?

US CDC recommends a variety of effective repellents. The most important step is to pick one and use it. There are those that can protect you for a short while in the backyard or a long while in the woods. DEET, picaridin, IR3535 and the plant-based oil of lemon eucalyptus are all repellents recommended by US CDC. All contain an EPA-registered active ingredient and have been studied to make sure they are effective and safe. EPA has a long listing of repellent brands in the United States. Check out US CDC’s traveler’s health page on repellents here.


When should you wear repellent?

Mosquitoes can bite anytime. Most of the mosquitoes that carry West Nile virus bite from around sundown to around sun-up (throughout the night). Put a few bottles or packets of repellent around—in the car, by the door, in a purse or backpack.