Disease trackers in Massachusetts and Maine are investigating two cases of a rare and severe tick-borne illness, providing new evidence of the suffering that can be inflicted by ticks and prompting warnings that the threat can persist into December.
Investigators suspect that the infections were caused by Powassan virus or a related virus, which can spawn headaches, vomiting, confusion, seizures, memory loss, and long-term neurological problems in those who survive the infection. The virus is believed to be fatal in 10 to 15 percent of those who are exposed.
Blood tests show that Lyn Snow, a Maine woman who died last week, was infected with the virus. Health officials said it appears Snow, from mid-coast Maine, had not been traveling and likely was infected locally. Full story for BostonGlobe.com subscribers.