EEE Information

 

Updated September 16, 2019

(Sections in bold contain the most up to date information)

  • During the summer of 2004, the Massachusetts Department of Public Health (MDPH) confirmed Eastern Equine Encephalitis (EEE) in four human cases, the first human cases in Massachusetts since 2001.  Two of the four human cases were fatal. The Massachusetts Department of Public Health (MDPH) also detected eastern equine encephalitis (EEE) virus in mosquitoes that bite both birds and humans.  Earlier detection of the EEE virus had been in mosquitoes that preferentially bite birds and not usually humans, horses and other mammals.
  • For 2005, four human cases of eastern equine encephalitis (EEE) were identified. All of the cases were identified in Plymouth County from the towns of Duxbury, Halifax, Kingston and Plymouth. All of the cases required hospitalization and there were two fatalities.
  • For 2006  there were five human cases of EEE.  The cases were from Bristol, Middlesex and Plymouth counties.  Two of the five cases were fatal.
  • For 2007, there were no human cases of EEE.
  • For 2008, 13 EEE-positive mosquito pools were detected in Massachusetts.   The pools were detected from six towns (Carver, Halifax, Berkley, Raynham, New Bedford and Freetown)  in two counties, (Plymouth and Bristol).  In 2008, there was one human case of EEE in Massachusetts, a resident of Essex county, over 64 years of age who had symptom onset in late September.  This was the first  fatal case since 2006, however the exposure was determined to be out-of state.
  •  For 2009, Fifty-four (54) EEE-positive mosquitoes were detected in 18 towns in 6 counties in Massachusetts.  There were no human cases of EEE for 2009.
  • For 2010, 65 of 3558 mosquito samples collected in Massachusetts were positive for EEE.  They were collected from 19 towns in 3 counties.  One human case of EEE infection (encephalitis) was identified in a Plymouth County resident.  A case from Rhode Island was also suspected to have been caused by an exposure in Southeastern Massachusetts.
  • For 2011, 80 of 4604 mosquito samples collected in Massachusetts were positive for EEE virus.  They were collected from 17 towns in 5 counties.  One fatal case of EEE infection was identified in a Bristol County resident aged 60 years or older, with an onset date of 8/27/2011 and a clinical presentation of meningioencephalitis.  A case was also identified in a Missouri resident aged 60 years or older with an onset date of 8/25/2011 and a clinical presentation of encephalitis.  An epidemiologic investigation determined that this individual was most likely exposed in Southeastern Massachusetts.
  • For 2012, 267 of 6828 mosquito samples collected in Massachusetts were positive for EEE virus.  They were collected from 43 towns in 8 counties.  There were seven human cases of EEE reported in Massachusetts in 2012, one from Middlesex County, which was believed to have been acquired out of state, one from Worcester County, one from Franklin County, two from Plymouth County, and two from Essex County.
  • For 2013, 61 of 6092 mosquito samples were positive for EEE. These positive samples were from 27 towns and 6 counties in the Commonwealth; one positive sample was found in Quincy.  There was one human case and fatality  in 2013, from Norfolk County.
  • For 2014, 33 0f 5039 mosquito samples were positive for EEE. These positive samples were from 13 towns in four counties in the Commonwealth.  No positive samples were found in Quincy.  There were no human cases or fatalities in Massachusetts for 2014.
  • For 2015, only one of 4527 mosquito samples was positive for EEE.  The sample was from the Town of Northbridge in Worcester County.  There were no human cases or fatalities from EEE in Massachusetts in 2015.
  • For 2016, 4 of 6414 mosquito samples were positive for EEE.  The samples were from Kingston, Middleboro, West Bridgewater and Yarmouth.  There were no human cases or fatalities from EEE in Massachusetts in 2016.
  • For 2017, one of 5496 mosquito samples was positive for EEE.  The sample was from the town of Westport in Bristol County.  There were no human cases or fatalities from EEE in Massachusetts in 2017.
  • For 2018, two of 5921 mosquito samples were positive for EEE. The mosquito samples were from Hubbardston and Lakeville.  There were no human cases or fatalities from EEE in Massachusetts in 2018.

2019: There have been 414 mosquito pools that have tested positive for EEE.  There have been eight human cases of EEE, one from Plymouth County, two from Worcester county, one from Hampden county,  two from Bristol county and two from Middlesex county.

County Town 

 Bristol

157

Easton (46); New Bedford (34); Freetown (16); Raynham (24); Rehoboth (18); Fairhaven; Dighton (3); Fall River (2); Acushnet; Westport (5); Norton; Dartmouth (6)

 Plymouth

163

Carver (35);  Halifax (5); Lakeville (12); Bridgewater (3); Mattapoisett (4); Rochester (18); Pembroke; Wareham (10); Kingston (13); Marion (15);  Middleborough (25);  West Bridgewater; East Bridgewater (2); Whitman (3); Duxbury (8), Hanson (6); Plympton; Norwell

 Barnstable

12

 Falmouth (7); Bourne (2); Truro (2); Wellfleet

 Norfolk

16

 Canton (6); Walpole (4); Avon (2); Weymouth (2); Cohasset; Dover

 Worcester

41

Southborough (13); Westborough (6); East Brookfield (3); Grafton (4); Upton; Harvard; Bolton (2);  Uxbridge (4); Mendon (2); Douglas; Millville; Shrewsbury; Holden (2)

 Middlesex

10

 Hopkinton; Lowell; Shirley (2); Bedford; Hudson; Marlboro; Sherborn; Holliston; Burlington

 Essex

8

Andover (4); Boxford; Methuen; West Newbury (2)

 Hampden

7

Agawam (3); East Longmeadow (2); Brimfield (2)