Fatal case of Powassan virus encephalitis in…

In the United States, according to a press release dated April 20, 2022 Maine Center for Disease Control and Prevention, a Waldo County, Maine resident died from Powassan virus infection transmitted through an infected tick bite. The patient developed neurological symptoms.
The statement said about 25 cases of Powassan virus infection are reported in the United States each year, with Maine having identified 14 cases since 2010.

Powassan virus reminders:

The Powassan virus of sex flavivirus is transmitted to humans by infected ticks (Ixodes). It is responsible for a disease with neurological tropism. In addition to humans, many animals can harbor this virus: marmots, rabbits, coyotes, foxes, raccoons and skunks, as well as domestic cats and dogs.

The disease is present in North America in Canada, in the United States with more than 40 cases since 1952, and in Russia. Seasonal incidence varies with tick activity (Ixodes cookei, Ixodes marxi, Ixodes spinipalpus), which serve as vectors, are higher in rural or wooded areas, and the risk of transmission is greatest from June to September.

After an incubation of 7 to 14 days, encephalitis occurs with, in milder forms, fever, headache or aseptic meningitis.
Clinical signs of infection can include fever, headache, vomiting, delirium, seizures, and memory loss. Neurological consequences can occur. There is no specific treatment, there is no vaccine.

The disease occurs mainly in forested areas with a seasonal occurrence (maximum transmission from June to September) according to tick activity. Ticks live in forests and undergrowth, tall grass, but also on golf courses and in public gardens.

To reduce the risk of infection, the traveler is advised to:

  • Wear clothing that covers the skin and socks that come down to the bottom of your pants.
  • Walk in the middle of the paths to avoid grass and bushes.
  • use a repellent containing 50% DEET on exposed areas and an insecticide containing permethrin on clothing;
  • Check regularly after a few hours that the body (thighs, arms, armpits and legs) is free of ticks.
  • If there is a tick, remove it with “tick tweezers” by grasping it as close as possible to the skin and gradually pulling (avoid squeezing the tick, burning it or applying various substances);
  • wash and disinfect sting area and hands;
  • If you have a fever, reddening of the skin (in the form of a ring), or other new symptoms after a tick bite, seek immediate medical attention.

Source: ProMED.

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