Mosquitoes infected with West Nile Virus now pose risks in the Greater Boston area, and have spread around Worcester and in the Pioneer Valley. That was announced by the state's Department of Public Health.

The state's deputy epidemiologist, Dr. Catherine Brown, says the activity this year around Worcester is unusual, and, she says the activity in western Massachusetts is unprecedented.

“The amount of mosquito activity and infected mosquitoes that we're finding in the Pioneer Valley really has not been seen in all of the time we've had West Nile here in Massachusetts,” Brown says.


Brown says since West Nile spread to Massachusetts in 2001, at least nine people have died, and nearly 150 have been known to be infected.

Most people are unaffected by the virus, around 20 percent have flu-like symptoms, and a very few number of people get severe symptoms — people over 50 are most at risk for that.

Brown says she hopes people will listen to her advice.

“Even if you don't like mosquito repellent, and you to tend to avoid listening to me the rest of the year, right now is the time to take it seriously," she says.

Brown says this month and next are peak time for mosquito-borne diseases like West Nile. And, she adds, using insect repellent is the best way to avoid them.