Babesiosis is caused by microscopic malaria-like parasites that infect the red blood cells. In the United States it is mostly caused by Babesia Microti, which is transmitted by the deer tick Ixodes Scapularis. Babesiosis mostly occurs in the Northeast and Upper Midwest. Around 1800 cases of Babesiosis are reported annually.​

Babesiosis can be a life-threatening condition in people who do not have a spleen, have a weak immune system, or have liver or kidney disease.

Signs and Symptoms​

Incubation period — 1-9+ weeks

  • Fever, chills, sweats
  • Fatigue
  • Headache
  • Loss of appetite and nausea
  • Dark Urine
High incidence areas tick borne disease babesiosis denoted on continental United States Map.

Geographic distribution of Babesiosis

Image courtesy of CDC

B. Microti in a thin blood smear

Image courtesy of CDC