ARBOVIRUS AVTIVIY IN MASSACHUSETTS: 2012 SEASON SUMMARY

M. Cynthia Stinson

Massachusetts Department of Public Health

Hinton State Laboratory Institute

305 South Street, Room 816

Jamaica Plain, MA 02130

cynthia.stinson@state.ma.us

ABSTRACT

2012 Arbovirus activity in Massachusetts included WNV and EEE mosquito isolates; EEE and WNV infection in humans and mammals. Two aerial adulticide applications were conducted in response to the threat of human EEE disease.

A total of 6820 mosquito pools were tested for the season. 307 mosquito pools were confirmed as WNV (+) and 267 pools were confirmed as EEE (+). Of the 307 WNV mosquito pools, 203 were identified as Culex pipiens/restuans. The remaining WNV isolates were identified in Culex species (60), Coquillettidia perturbans (7), Culex Salinarius (5), Culiseta melanura (30), and Aedes vexans (2). Of the 267 EEEv mosquito pools, 146 were identified in the enzootic vector species, Culiseta melanura. The remaining isolates were identified in Coquillettidia perturbans (62), Culex pipiens/restuans (16), Ochlerotatus canadensis (15), Aedes vexans (7), Culex territans(3), Culex salinarius(13), Culex species(5). A total of 27 WNV human cases and 7 EEE cases were confirmed. Mammal activity included 2 WNV positive horses and 6 EEE positive mammals.