Is EEE still a risk?

Update on EEE risk

If you’ve been keeping up with the news, you know that this year has been a particularly active year for Eastern equine encephalitis, also known as EEE or Triple E, a mosquito-borne illness that causes inflammation of the brain. We reported on EEE last month offering some facts about the disease and how to prevent it.

Since we last discussed EEE, the disease has continued to be a risk for those in Massachusetts and even beyond. Owing to an unusually warm autumn season, areas like Sudbury, Framingham, and Hopkinton are still at “high” and “critical” risk for EEE. Towns have begun to consider how Halloween festivities should be handled, and if Halloween should be celebrated at all.

Is Halloween cancelled because of EEE?

Many towns have already made changes to regularly scheduled activities such as outdoor sports, and some have specifically made announcements regarding Halloween festivities. On October 4, the mayor of Methuen, James Jajuga, announced that trick-or-treating will be limited from 4:30 p.m.-6 p.m. instead of the traditional hours of 5-7 p.m. Other towns have yet to make Halloween announcements and have simply urged caution among those going out after dusk, whether it be for Halloween or not. For example, as of September 20, the town of Andover recommends that outdoor activities be cancelled at 6 p.m. from October 27-October 31. Methuen and Andover have not found any positive EEE tests in humans in over a month (though a horse did test positive in Methuen), but city officials are remaining on alert until the risk level goes down.

Hard frost to kill mosquitoes

The risk and spread of EEE is dependent on mosquitoes, which transmit the disease to humans and horses via bites. Officials and public health researchers have stated that a “hard frost” is needed to kill off the mosquitoes and lower the risk of EEE in Massachusetts. However, this does not mean just any frost. Some towns have already experienced a mild frost this season, and although these frosts can reduce mosquito populations, they are not enough to eliminate the risk of EEE. A hard frost means that the temperature is below 28 degrees Fahrenheit for several consecutive hours, and ideally, this will happen for several successive days. Once it’s cold enough outside for the ground to freeze, towns can be sure that mosquitoes will be dying off.

Preventing EEE

In the past, the first hard frost tended to happen around the beginning of November. However, autumn has been warmer than usual this year, and thus the first hard frost may not come until mid-November or later. In the meantime, we encourage you and your patients to use mosquito repellent with DEET and wear protective clothing like long-sleeved shirts, pants, and shoes with socks. Pay attention to your town’s news and look out for recommendations on how late is safe to be out, and if Halloween festivities will be shortened or cancelled. If your town decides to change its Halloween celebration, follow their recommendations and encourage your patients to follow suit.