One tick-borne disease, babesiosis, has been increasing its range dramatically in recent years. The same ticks that carry Lyme disease (Ixodes scapularis) also transmit babesiosis. That is why we are not surprised that this infection is spreading to the same regions as Lyme disease.
Babesiosis is caused by protozoa (Babesia microti) that hide in red blood cells just as malaria parasites do. Some people with babesiosis never develop any symptoms. These pathogens usually cause flu-like illness, however. People often experience symptoms of fever, chills, headache and fatigue.
Anemia due to the breakdown of red blood cells is a common complication. This acute anemia clears when the patient is treated with appropriate antibiotics. Most often, doctors prescribe a combination of antimicrobial drugs to knock these germs out.
Severe Anemia Can Occur Even After Treatment:
A case series reported in the New England Journal of Medicine reveals that even after babesiosis has been successfully treated with antibiotics, some people develop a severe anemia caused by autoimmune destruction of red blood cells. Patients who do not have spleens appear to be at higher risk. Two-thirds of the patients in the report required immune-suppressing drugs to reverse their severe anemia.
Wooley et al, New England Journal of Medicine, March 8, 2017