Tickborne diseases have been on the rise in the US, with a 25% increase in cases from 2011 to 2019. Among them, babesiosis has become significantly more prevalent in the Northeast region. Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin were already considered to have endemic transmission of the disease. However, a new report from the Centers for Disease Control and Prevention (CDC) added three more states to the list: Maine, New Hampshire, and Vermont, where case rates have grown the fastest and now match or surpass other states.
Reported cases of babesiosis have increased in all of the ten endemic states except for Minnesota and Wisconsin, where case rates were about 30% lower in 2019 than in 2011. Between 2011 and 2019, over 16,000 cases of babesiosis have been reported to the CDC.
Symptoms of babesiosis include fever, muscle and joint pain, and headache. It can range from mild to severe, and in rare cases, it can be fatal. Infections can also be asymptomatic, so patients may not always know to be tested. The CDC warns that the increasing prevalence of babesiosis could pose risks to the blood supply as the disease is transmissible through blood transfusion. Infections acquired through blood transfusion have significantly worse outcomes and higher risk of death than those acquired through a tick bite, according to the report. The US Food and Drug Administration recommends blood donation screening for babesiosis in 14 states and Washington, DC, in and around areas where transmission is endemic.
The CDC recommends that people spending time outdoors in states with endemic babesiosis practice tick bite prevention, including wearing long pants, avoiding underbrush and long grass, and using tick repellents.