Tick-borne illness is on the rise in the US, with cases increasing 25% between 2011 and 2019. One is babesiosis, which has become significantly more common in the Northeast in recent years.
Seven states were already believed to have endemic transmission of babesiosis, with consistent presences of the disease: Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin. A new report from the U.S. Centers for Disease Control and Prevention added three more to that list — Maine, New Hampshire and Vermont — where case numbers have grown the fastest and now match or exceed other states.
In those 10 states, reported babesiosis cases have increased in all but two states: Minnesota and Wisconsin, where the number of cases in 2019 was about 30% lower than in 2011.
According to the report, a total of more than 16,000 cases of babesiosis were reported to the CDC between 2011 and 2019.
Symptoms of the disease include fever, muscle and joint pain, and headache. Illness can range from mild to severe and in rare cases can be fatal. Infections can also be asymptomatic, so patients may not always know they need to be tested.
The CDC warns that the increasing prevalence of babesiosis may pose risks to the blood supply. The disease is transmissible through blood transfusion, and infections acquired this way appear to have significantly worse outcomes and a higher risk of death than infections acquired from a tick bite, the report said. The U.S. Food and Drug Administration is currently recommending blood donations to screen for babesiosis in 14 states and Washington, DC, in and around areas where transmission is endemic.
“Individuals who spend time outdoors in states with endemic babesiosis should practice tick bite prevention, including wearing long pants, avoiding undergrowth and long grass, and using tick repellents,” the CDC said.