Babesiosis is a parasitic infection carried in mice and other rodents. The disease, carried to humans by ticks, attacks the red blood cells and causes symptoms often mistaken for the flu. Unlike Lyme disease, with its distinctive target-shaped rash, tick bites carrying babesiosis are often undetected. Symptoms appear one to six weeks after a tick bite and can last several weeks or months. We are concerned that it may be more widespread than we have previously thought.
Diagnostic tests are still fairly new so diagnosis is difficult.
Babesiosis was recognized in the Northeast in the 1960s and became endemic by the 1980s in Nantucket, Martha's Vineyard, Shelter Island, and parts of Long Island, as well as other areas along the northeastern seaboard, according to Mary Shepherd, who is with the CDC's infectious disease branch. Cases recently have been reported in New Jersey. According to Dr. Sean O. Henderson, an assistant professor at the University of Southern California School of Medicine, hundreds of cases have been reported since the first domestic case in 1966. The increasing number of cases over the past 30 years may be the result of restocking of the deer population, curtailment of hunting and an increase in outdoor recreational activities, he explained. Treatment of severe infection has had only limited success, according to the CDC, but the disease, if properly diagnosed, can be treated in earlier stages because of its similarity to malaria.