What is babesiosis?

Babesiosis is a disease caused by a microscopic parasite (a type of germ similar to those that cause malaria) that infects red blood cells.

Where do cases of babesiosis occur?

Babesiosis occurs in many areas in the northeastern United States.  In Massachusetts, the disease occurs most frequently in coastal areas like the South Coast, the South Shore, Cape Cod, and the islands of Martha’s Vineyard and Nantucket. Despite a higher occurrence of disease in certain areas of Massachusetts, it is found everywhere in the state.

How is babesiosis spread?

Babesiosis is spread by the bite of an infected black-legged (deer) tick.  The longer a tick remains attached and feeding, the higher the likelihood that it may spread the parasite.  The tick must generally be attached to a person for at least 24-36 hours before it can spread the germ.  Black-legged ticks in Massachusetts can also carry the germs that cause Lyme disease and human granulocytic anaplasmosis These ticks are capable of spreading more than one type of germ in a single bite.

When can I get babesiosis?

Babesiosis can occur during any time of the year.  The parasite that causes babesiosis is spread by infected black-legged ticks.  Young ticks (nymphs) are most active during the warm weather months between May and July. Adult ticks are most active during the fall and spring but may also be out searching for a host any time that winter temperatures are above freezing.

How soon do symptoms of babesiosis appear after a tick bite?

Symptoms of babesiosis usually begin to appear from 1 to 8 weeks after being bitten by an infected tick.

What are the symptoms of babesiosis?

Most people who are infected by the parasite will show very mild signs of illness or no signs at all.  If symptoms occur, they may include fever, chills, headache, achy joints and muscles, fatigue, nausea, vomiting, abdominal pain and dark urine.  Symptoms can last for up to several months.  The elderly, people without a healthy spleen, and people with weakened immune systems are more likely to develop potentially life-threatening symptoms.

Is there treatment for babesiosis?

Babesiosis can be treated with medication; however, serious complications requiring a blood transfusion and/or kidney dialysis can occur if the disease is not recognized and treated early.