Babesiosis is a disease caused by an infection with a parasite called Babesia. These parasites can be transmitted to humans by the bite of an infected black-legged tick (Ixodes scapularis), the same tick that transmits Lyme disease and anaplasmosis. Rarely, Babesia can be transmitted by blood transfusions or from a pregnant woman to the fetus.
Many people who have been infected with Babesia do not experience any symptoms.
When symptoms do occur, they typically begin one to four weeks after the tick bite and can include fever, chills, sweats, headache, body aches, loss of appetite, nausea, or fatigue. Babesiosis can also cause a particular type of anemia, which makes a person develop jaundice (yellowing of the skin) and have dark urine.
Anyone can get sick with babesiosis, but people who have compromised immune systems, kidney or liver disease, those who do not have a spleen, and older adults are at greater risk for serious complications, including death.
Babesiosis can be diagnosed using blood tests. The disease can be successfully treated with the appropriate medical care.
Babesiosis is the third most commonly reported tickborne disease in Vermont. Between 2005 and 2015 an average of three cases per year were reported to the Health Department.
While fewer than 40 cases of babesiosis have ever been reported in Vermont, a vast majority of those cases have occurred in residents of the state’s southern-most counties: Bennington, Rutland, Windsor and Windham.
The risk for contracting babesiosis exists whenever black-legged ticks are active, but almost three-quarters of reported cases in Vermont fell ill between June and August. And, while anyone can get babesiosis, 70% of the cases reported to the Health Department are in Vermonters 55 years of age or older.