Epi Week #39 - 2017 General Statements

September 24 – September 30

There have been 290 WNV-positive mosquito pools found in 90 cities/towns so far this season, with WNV activity in every mainland county in the state. Currently, 155 municipalities in 11 counties are at a MODERATE risk for WNV, which is more than 40% of the state. In addition, we continue to see high levels of Culiseta melanura in the collections, even this late in the season. The EEEv risk for this season, however, remains extremely low, with only 1 positive pool so far. Unseasonably warm weather will continue to prolong WNV risk. We should finally see a break from the heat in the middle of Epi Week 41.

Weather

Epi Week 39 was dry across the entire state, with little rain, and all mainland counties except Barnstable County now at a drought level of Abnormally Dry (D0 - yellow)

Map of Abnormally Dry Weather in MA

Percipitation in MA for EPI Week 39

At the time this report goes to press, above-average temperatures and dry conditions persist. Rain is expected at the end of Epi Week 41, followed by a return to fall-like temperatures.