The Massachusetts Department of Public Health has identified 36 municipalities with heightened risk levels of Eastern Equine Encephalitis (EEE) exposure. Currently, Boston and abutting communities to the north are listed as low-risk for exposure to EEE. However, we should consider proper steps for our community members traveling to areas of moderate or higher risk levels, along with anticipating the possibility of Boston’s risk level increasing.
This risk will remain until the first hard frost kills of most of the target mosquito species (Culiseta melanura), which is expected to occur in November at the earliest for most of Boston and the surrounding areas. Please see the following links for information on the current risk level and preventative measures, along with general information on EEE.
The populations at highest risk for EEE infection are young children, the elderly, and people with compromised immune systems.
The Mass DPH’s categorization of ‘low’ risk advises the following preventative measures to reduce the likelihood of exposure to this pathogen:
- Wear mosquito repellent between dusk and dawn
- The recommended mosquito repellents include
- DEET
- Picaridin (known as KBR 3023 and icaridin outside the US)
- IR3535
- Oil of lemon eucalyptus (OLE)
- Para-menthane-diol (PMD)
- 2-undecanone
- Generally speaking, these repellents should be applied at least every 2-4 hours when outdoors between dusk and dawn
- The manufacturers recommended application rate should be followed for the best protection
- The recommended mosquito repellents include
- Wear long sleeves and pants between dusk and dawn to reduce the amount of exposed skin
- Use mosquito netting on baby carriages and playpens
Should the Mass DPH increase Boston’s risk level to moderate, the following preventative measures are recommended in addition to the steps above:
- Wear mosquito repellent when outdoors, even before dusk and after dawn
- Avoid outdoor areas with obvious mosquito activity
Once infected with EEE, most symptoms occur within 4-10 days. Symptoms of EEE exposure to be on the lookout for include the following:
- Systemic infection (general infection of the body)
- Abrupt onset characterized by chills, fever, malaise (general discomfort), arthralgia (joint paint), and myalgia (muscle pain). The illness lasts 1 to 2 weeks, and recovery is complete when there is no central nervous system involvement.
- Encephalitic infection (acute inflammation of the brain)
- Abrupt onset characterized by fever, headache, irritability, restlessness, drowsiness, anorexia, vomiting, diarrhea, cyanosis (bluish discoloration of the skin), convulsions, and coma.
As there is no vaccine or specific antiviral treatment for EEE, and approximately 33% of all infection leads to death, any of these symptoms should be thoroughly investigated by health care providers to provide the best chance for survival and long term vitality after symptoms disappear.
It would be a good idea to have personnel on the lookout for any standing water that may be collecting around campus and ensure this water is drained or otherwise not allowed to sit stagnant, as this is a risk factor for mosquito reproduction and increased exposure risk.
The Mass DPH recommends that any personnel traveling to the following municipalities (listed at CRITICAL risk) cancel or reschedule outdoor gatherings, organized sporting events, etc. to avoid peak mosquito hours of dusk to dawn until further notice. It would be prudent for personnel to heed this advice.
| Acushnet |
| Ashland |
| Brookfield |
| Carver |
| Colrain |
| Douglas |
| Easton |
| Framingham |
| Freetown |
| Grafton |
| Granby |
| Heath |
| Holliston |
| Hopkinton |
| Lakeville |
| Marlborough |
| Medfield |
| Mendon |
| Methuen |
| Middleborough |
| New Bedford |
| Northborough |
| Norton |
| Raynham |
| Rochester |
| Sudbury |
| Upton |
| Uxbridge |
| Wareham |