Many people who are infected with Babesia microti feel fine and do not have any symptoms. Some people develop nonspecific flu-like symptoms, such as fever, chills, sweats, headache, body aches, loss of appetite, nausea, or fatigue.
Because Babesia parasites infect and destroy red blood cells, babesiosis can cause a special type of anemia called hemolytic anemia. This type of anemia can lead to jaundice (yellowing of the skin) and dark urine.
Babesiosis can be a severe, life-threatening disease, particularly in people who:
- do not have a spleen;
- have a weak immune system for other reasons (such as cancer, lymphoma, or AIDS);
- have other serious health conditions (such as liver or kidney disease); or
- are elderly.
Complications of babesiosis can include:
- a low and unstable blood pressure;
- severe hemolytic anemia (hemolysis);
- a very low platelet count (thrombocytopenia);
- disseminated intravascular coagulation (also known as “DIC” or consumptive coagulopathy), which can lead to blood clots and bleeding;
- malfunction of vital organs (such as the kidneys, lungs, and liver); or