Babesiosis

Updated: October 2011

What is babesiosis?

Babesiosis is a rare, severe and sometimes fatal tick-borne disease caused by various types of Babesia, a microscopic parasite that infects red blood cells. In New York state, the causative parasite is Babesia microti.

Who gets babesiosis?

While anyone can get babesiosis, it can be more severe in the elderly, people who have had their spleen removed or in immunocompromised individuals. Cases of this disease in the U.S. have been primarily reported during spring, summer and fall in coastal areas in the Northeast, including on Long Island in New York State, Nantucket Island off the coast of Massachusetts and in New Jersey. Cases also have been reported in the some upper Midwest states, including Wisconsin and Minnesota, and in California, Georgia, Missouri and some European countries.

How is babesiosis transmitted?

Babesiosis is transmitted by the bite of an infected deer tick, Ixodes scapularis. Transmission can also occur via transfusion of contaminated blood and possibly from an infected mother to her baby during pregnancy or delivery.

What are the symptoms of babesiosis?

The disease can cause fever, fatigue and hemolytic anemia lasting from several days to several months. Infections can occur without producing symptoms.

When do symptoms appear?

It may take from one to eight weeks, sometimes longer, for symptoms to appear.

Does past infection with babesiosis make a person immune?

It is not known whether past infection with babesiosis can make a person immune.

What is the treatment for babesiosis?

While many people do not become sick enough with babesiosis to require treatment, there are effective therapies, usually either a combination of quinine and clindamycin or a combination of atovaquone and azithromycin. It is possible to become infected with babesiosis and Lyme disease at the same time, so be sure to seek medical attention if you become ill after a tick bite.

What can be done to prevent babesiosis?

A thorough check of body surfaces for attached ticks should be done when leaving tick habitat, and again at the end of the day. With babesiosis if removal of attached ticks occurs within 24 hours, the risk of tick-borne infection is minimal.

How should a tick be removed?

Grasp the mouthparts with tweezers as close as possible to the attachment (skin) site. Be careful not to squeeze, crush or puncture the body of the tick, which may contain infectious fluids. After removing the tick, thoroughly disinfect the bite site and wash hands. See or call a doctor if there are concerns about incomplete tick removal. Do not attempt to remove ticks by using petroleum jelly, lit cigarettes or other home remedies because these may actually increase the chance of contracting a tick-borne disease.