Physician Says Prevention Is the Best Way to Combat Mosquitos

WARE — It doesn’t take much for mosquitos to breed, said Dr. Richard Gerstein, chair of Emergency Medicine at Baystate Mary Lane Hospital.

 “The main rule when it comes to breeding grounds for mosquitoes is that they need stagnant water in order to lay their eggs,” he said. “What most people don’t realize is the surprising number of areas around their own house where mosquitoes can find the stagnant water they need. Any temporary body of water that is present for more than a week can be a mosquito-breeding habitat. Even flooded tire tracks and footprints in a muddy field have been known to produce dozens of mosquitoes each.”

According to the state Department of Public Health, more than 3,000 different species of mosquitoes have been identified worldwide, with more than 150 in North America. Fifty-one different kinds of mosquitoes have been found in Massachusetts. Only female mosquitoes bite to suck blood and use the blood to make eggs. Mosquitoes are attracted to carbon dioxide, a gas that humans and other animals breathe out, and can follow a stream of carbon dioxide from as far as 50 feet away.

 “Some mosquitoes carry germs that can make people and some animals sick,” said Gerstein, adding that the diseases linked to mosquitoes in Massachusetts are West Nile virus (WNV) and eastern equine encephalitis (EEE) virus. EEE is relatively rare in humans, although there are occasional outbreaks in certain regions of the country. Fewer than 100 people have died from EEE in Massachusetts in the past 75 years, according to the U.S. Department of Public Health.

“It is possible that some people who become infected with mosquito-borne viruses may not develop any symptoms or, in some cases, only flu-like symptoms,” said Gerstein. “The incubation period for the virus from the time of an infected mosquito bite to onset of illness ranges from four to 10 days, and the illness can last one to two weeks. Those infected usually develop lifelong immunity.”

West Nile virus (WNV) is a mosquito-carried virus most commonly spread to people through the bite of an infected mosquito.

 “The majority of people who are infected with WNV, approximately 80{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5}, will have no symptoms,” Gerstein noted. “A smaller number of people who become infected, less than 20{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5}, will have symptoms such as fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands.

Gerstein encourages community members to follow Department of Public Health tips to protect themselves and their loved ones from illnesses caused by mosquitoes:

• Be aware of peak mosquito hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning.

• Apply insect repellent when outdoors. Use a repellent with DEET, oil of lemon eucalyptus, or IR3535 according to the instructions on the product label. DEET products should not be used on infants under 2 months of age and should be used in concentrations of 30{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} or less on older children. Oil of lemon eucalyptus should not be used on children under 3.

• Clothing can help reduce mosquito bites. Wearing long sleeves, long pants, and socks when outdoors will help keep mosquitoes away from your skin.

• Mosquito-proof your home. Limit the number of places around your home for mosquitoes to breed by either draining or discarding items that hold water. Remove containers that may hold water in places that are hard to see, such as under bushes, porches, decks, or stairs.

• Install or repair screens. Keep mosquitoes outside by having tightly fitting       screens on all of your windows and doors.

More information about different types of mosquitoes that can spread disease can be found on the MDPH website at mass.gov/dph/wnv.