27M h/o sickle cell anemia presents with high fevers, sweats, HA, muscle aches, N/V.  Recent camping trip in New England.  Blood smear shows the following:

 

Diagnosis?

What complications would you worry about?  

 

 

 

BABESIOSIS

Babesiosis is an infection caused by a malaria-like parasite, Babesia, a genus of protozoal piroplasms.   Ticks may carry only Babesia or they may be infected with both Babesia and Lyme spirochetes. People can also get babesiosis from a contaminated blood transfusion.

Symptoms often start with a high fever and chills.  Patients may develop fatigue, headache, drenching sweats, muscle aches, nausea, and vomiting.  Babesiosis can be life-threatening to people with no spleen, the elderly, and people with weak immune systems.

Complications include severe hemolytic anemia, hypotension, liver problems, thrombocytopenia, and kidney failure.

Diagnosis:  Blood smears may be examined under a microscope to try to identify the parasite inside red blood cells, however this method is reliable only in the first two weeks of the infection. “Maltese cross formation” as seen in the picture are diagnostic.  PCR, FISH, and antibodies to Babesia may also be used.

Treatment:  combination of 2 anti-parasitic drugs.  Preferred regimen is atovaquone plus an erythromycin.