The Centers for Disease Control and Prevention (CDC) says that Americans living in eight northeastern U.S. states should be aware of the signs of babesiosis, a tick-borne disease that is on the rise.
Unlike Lyme disease, caused by several types of borrellia bacteria, babesiosis is caused by the babesia parasite that can infect red blood cells—not unlike malaria. Some medical professionals describe babesia—along with anaplasmosis, the Powassan virus, sometimes bartonella, and others—as a “co-infection” to Lyme disease that are transmitted via tick bites.
“Members of the public and health care providers in states with endemic babesiosis and bordering states should be aware of the clinical signs of babesiosis and risk factors for Babesia infection. Persons spending time outdoors in states with endemic babesiosis should practice tick bite prevention, including wearing long pants, avoiding underbrush and long grass, and using tick repellents,” said the CDC.
People can also contract the babesia parasite through contaminated blood transfusions and organ transplants. Pregnant mothers who have babesiosis can transmit it to their babies, the CDC said.
“Babesia is much more of a problem than the general public recognizes and can be fatal—up to 20 percent—in people who have HIV/AIDS or severe cancer with chemotherapy or individuals who lack a spleen,” Krause told the outlet.

Symptoms and Treatment
To treat babesiosis, the CDC recommends prescription antimicrobial medications such as atovaquone including azithromycin or a combination of clindamycin and quinine in acute cases.High-risk patients may suffer “multi-organ dysfunction, including respiratory distress, congestive heart failure, renal failure, splenic rupture, disseminated intravascular coagulation (DIC), hepatitis, or coma,” says the National Institutes of Health.
Friday’s CDC report said that a total of 16,456 cases of babesiosis were reported to the agency in 37 states between 2011 and 2019. New York state reported the highest number of cases, or about 4,738 in total, while Massachusetts was No. 2 and Connecticut was No. 3.
The CDC noted that some states, including Pennsylvania—where Lyme disease is considered endemic—do not report babesiosis. The report further stated that Friday’s data likely don’t “represent all incident cases of babesiosis in reporting states” while patients with “nonspecific symptoms might not be tested for babesiosis.”