Powassan (POW) virus is a flavivirus and currently the only well documented tick-borne transmitted arbovirus occurring in the United States and Canada. Powassan encephalitis is a serious illness caused by the Powassan virus. This virus was first recognized in the small town of Powassan, Ontario in 1958. Due to the ability of the virus to cause encephalitis, it was and still is considered a very serious tick-borne illness.

Powassan encephalitis can cause residual neurological problems in patient who recover. Powassan in not common in humans, but Maine has seen a few human cases in last decade. Powassan can be carried by the deer tick (Ixodes scapularis).

Maine CDC confirmed three deaths in Maine residents with Powassan virus since 2013. See the tables below of reported positive Powassan virus cases in Maine for more information.

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Reported Positive Human Cases in Maine 2022

Reported Positive Human Cases in Maine in 2022
Collection Date County
6/17/2022 Penobscot
6/2/2022 Cumberland
3/18/2022 Waldo
1/14/2022 York

Reported Positive Human Cases in Maine since 2013

Reported Positive Human Cases in Maine since 2013
Report Year Collection Date County
2021 6/20/2021 Knox
2021 6/10/2021 Cumberland
2021 5/25/2021 Waldo
2020 12/1/2020 York
2019 11/22/2019 Cumberland
2019 6/28/2019 York
2017 6/7/2017 Cumberland
2017 5/3/2017 Knox
2017 4/30/2017 Knox
2016 10/22/2016 Cumberland
2015 12/1/2015 Cumberland
2013 10/31/2013 Knox

Powassan Virus Press Releases

See the most recent Maine CDC press release about Powassan virus cases in Maine.

Resources for Maine Residents

Other Vector-borne Diseases