Powassan virus, a little-known disease that’s incurable and can be deadly, is spreading rapidly alongside Lyme disease, which is also spread by ticks. Powassan virus caused the first fatality linked to the disease in 2023 when a 58-year-old man died of complications caused by the disease. Cases of Powassan are rising fast and many doctors are unfamiliar with the once-rare disease, making accurate diagnoses a problem. While only six US cases of Powassan were recorded in 2015, a record 39 cases were reported in 2019. All tick-borne diseases, including Powassan virus, are on the rise, according to the Centers for Disease Control and Prevention (CDC), with other tick-borne diseases like anaplasmosis, babesiosis, tularemia and Rocky Mountain spotted fever also showing increases.
Nine years of CDC data show an increase in tick-borne disease in parts of the US that previously saw few cases. Powassan virus is of particular concern because of the ease with which the disease spreads. A tick attached to a human needs 36 to 48 hours to transfer Lyme disease, but it can transfer the Powassan virus in just 15 minutes. Humans with Powassan virus do not always show symptoms, but if they do, flu-like symptoms such as fever, headache or vomiting can appear one week to one month after being bitten.
More serious symptoms can include brain or spinal inflammation, confusion, seizures and difficulty with speaking and coordination. Most Powassan virus cases have occurred in the northeastern US from Maine, south to Virginia and westward across the Great Lakes region to Minnesota. Other cases have been reported in Russia and Canada.
There is no cure for Powassan virus; doctors prescribe rest, fluids and over-the-counter painkillers for most cases, which can last up to a month. More serious cases may require hospitalisation for breathing support and to reduce swelling in the brain. About 10% of people with severe Powassan virus die, according to the Maine CDC. Those who survive may have long-term health problems like headaches, memory problems and a loss of muscle strength.
Experts have noted that a warming climate helps to spread Powassan and other tick-borne diseases. Milder winters and earlier spring seasons create perfect conditions for warm-weather pests like ticks. The primary season for tick activity, and reports of tick-borne illnesses, typically starts in March and peaks in May and June, with a second, smaller increase in mid-autumn. The most efficient way to protect against tick-borne disease is by using insect repellent and wearing clothes that cover your skin in areas with high tick populations, as well as checking yourself and your pets for ticks.
There is some hope on the horizon, as both Moderna and, in collaboration, Pfizer and Valneva are developing vaccines for Lyme disease, potentially available as soon as 2025. However, there is currently no vaccine for Powassan virus. With both diseases on the rise, it is vital to take precautions to prevent tick bites.
