Tick-Borne Babesiosis In MN: What To Know As Illnesses Increase

MINNESOTA — Babesiosis, a dangerous and in rare cases deadly tick-borne disease that is endemic in Minnesota, is on the rise in other parts of the country, the Centers for Disease Control and Prevention said in a report Thursday.

Cases of babesiosis, which is largely transmitted through blacklegged tick bites, increased in eight of the 10 northeastern states that reported illnesses from 2011 to 2019.

The number of cases declined in both Minnesota and Wisconsin. But the disease's endemic status there means it's a constant presence and residents need to take precautions.

Also, the CDC said, three new states — Maine, New Hampshire and Vermont — joined the list of states where babesiosis is now considered endemic. The disease is already considered endemic in Connecticut, Massachusetts, New Jersey, New York and Rhode Island.

The first U.S. case of babesiosis was reported on Nantucket Island, Massachusetts, in 1969, but the CDC didn’t ask state health departments to report it until 2011. Overall, tick-borne diseases increased 25 percent from 40,795 reported illnesses in 2011 to 50,856 in 2019, according to the report.

Between 2011-2019, 16,456 cases of babesiosis were reported to the CDC nationwide.

Minnesota saw a 28.2 percent drop in babesiosis cases, from 73 cases in 2011 to 55 in 2019. A total of 486 cases were reported in Minnesota during that time period.

In 2019, the Food and Drug Administration recommended screening blood donations for babesiosis in 15 states — the 10 where it is now endemic, including in Minnesota, but also in Delaware, Maryland, Pennsylvania, Virginia, and the District of Columbia.

Symptoms of babesiosis can include fever, chills, sweats, headaches, body aches, nausea, fatigue, and muscle and joint pain.

Illnesses may be asymptomatic, mild or severe. In rare cases, the disease can be fatal, especially for people who are immunocompromised or lack a spleen. Federal health data shows up to 20 percent of adult cases and 50 percent of pediatric cases are asymptomatic, but illnesses can also range from mild to severe, with complications including plummeting blood platelets, kidney failure or acute respiratory distress syndrome, which causes a buildup of fluid in the lungs.

The illness can be treated with a combination of antimicrobial medications, such as azithromycin and atovaquone, according to the CDC.

To avoid tick bites, the CDC said:

• Wear long pants when spending time outdoors;
• Stay out of underbrush and long grass;
• Use a tick repellant.

The researchers said babesiosis is likely more common than indicated by the data, which is incomplete because not all states report cases to the CDC and asymptomatic cases aren’t flagged by physicians.

Babesiosis can also be spread through blood transfusions and organ donations from an infected person, or from mother to child during pregnancy, according to the CDC.

The aching and fever associated with babesiosis can sometimes be confused with Lyme disease, but it is distinguished by a rash at the site of the tick bite. About 30,000 cases of Lyme disease are reported annually, according to the CDC.

A forecast wet spring in the eastern half of the country could create ideal conditions for ticks, which are usually active from late May until early September. Scientists think longer summers contribute to an increase in tick-borne illnesses. Also, exploding deer populations have given the blacklegged tick — often commonly known as a deer tick — more hosts for feeding and reproduction.