This tick-borne disease is now endemic in 10 U.S. states

Babesiosis, a tick-borne disease, is endemic in 10 U.S. states, according to a March 2023 report by the Atlanta-based Centers for Disease Control and Prevention (CDC). The parasitic disease primarily occurs within the Northeast and Midwest. As cases continue to rise in several states, the CDC has advised for an increase in tick prevention messaging and traveler risk awareness.

“During 2011–2019, U.S. babesiosis incidence significantly increased in northeastern states,” the CDC reported. “Three states (Maine, New Hampshire, and Vermont) that were not considered to have endemic babesiosis had significantly increasing incidences and reported case counts similar to or higher than those in the seven states with known endemic transmission.”

Babesiosis is now considered endemic in Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, Wisconsin, Maine, New Hampshire, and Vermont.

“During 2011–2019, a total of 16,456 cases of babesiosis were reported to CDC by 37 states, including 16,174 (98.2%) reported from the 10 states included in this analysis,” the CDC reported. While babesiosis can range from eliciting severe symptoms to being completely asymptomatic, certain patients can experience complications such as thrombocytopenia, renal failure, and acute respiratory distress syndrome. Common symptoms of babesiosis include fever, muscle pain, joint pain and headache.

The worst symptoms of the parasitic disease, however, are often the result of blood transfusions.

“Babesia is transmissible via blood transfusion, and persons who acquire babesiosis through contaminated blood have been shown to have significantly worse health outcomes and a higher risk for death than do those who acquire the disease from a tick bite,” the CDC reported.

“Currently, the FDA recommends blood donation screening for babesiosis in 14 states and the District of Columbia. Babesiosis risk in Maine, New Hampshire, and Vermont is comparable to that in the northeastern and midwestern states where babesiosis has been considered endemic, and FDA guidance recommends blood donor screening for Babesia infection in those states. Ongoing evaluation of both tickborne and transfusion transmission risks in states that border those with endemic transmission is important for the evaluation and evolution of babesiosis blood screening policy.”