West Nile Virus Detected In Mosquitoes In Massachusetts

Jul 8, 2016

Health officials in Massachusetts are recommending people take precautions this summer to protect themselves from mosquitoes that can spread illness. The much discussed Zika virus is a concern for people traveling out of the area, but there are local risks like West Nile Virus and Eastern Equine Encephalitis.

Massachusetts health officials Thursday announced that West Nile Virus had been detected in mosquitoes in the state for the first time this year. The virus was found in three mosquito samples collected on July 1st in the city of Worcester.

Catherine Brown, Deputy State Epidemiologist with the Massachusetts Department of Public Health, said weather conditions are just about perfect for increased West Nile Virus activity.

"We know that hot,dry years tend to be when West Nile Virus is most active," said Brown.

People can contract West Nile Virus through the bite of an infected mosquito. Last year in Massachusetts there were 10 confirmed human cases of West Nile Virus.  Most people infected with the virus will show no symptoms. Some will have fever and flu-like sickness. In rare cases the virus can produce serious illness.

" The severe form of the disease is more common in individuals over 50 and those whose immune systems are compromised and so they can't handle the virus," Brown explained.

Brown said it is not so easy to predict based on weather conditions the possibility of an Eastern Equine Encephalitis (EEE) outbreak.  Cases of EEE in humans are very rare, but are fatal in about half of all cases.

Health officials say avoiding mosquito bites is the best way to reduce risk.  Recommendations include: remain indoors from dusk to dawn, the peak time for mosquito activity. Wear long sleeves, long pants and socks to cover the skin. Use insect repellent.

"I know there is concern in some people about the use of repellents, so what we encourage is using a repellent that contains an EPA-registered active ingredient," said Brown. " The advantage is the manufacturer must show the EPA the product is both safe and effective."

Large areas of eastern Massachusetts and sections of the Berkshires are included in Mosquito Control Districts where the insects are regularly tested for the presence of diseases, but there are no such early warning systems anywhere in Hampden, Hampshire, and Franklin counties. As a result, 500,000 people are at risk, according to West Springfield Director of Public Health Jeanne Galloway.

" The prevalence of the mosquitos can be greater in highly populated low income areas which we have a number of spread throughout ( the three ) counties," said Galloway.

If an outbreak of a mosquito-borne illness were to occur in the area local officials would need emergency help from the state to reduce the mosquito population.

" Right now, even  if we had a horse diagnosed with EEE there is very little response we could do," said Galloway.

Setting up a mosquito control district would require municipalities to contribute a share of their unrestricted local aid to fund the project.

Mosquito control districts in Massachusetts have budgets ranging from $300,000-$500,000.