Babesiosis
| Pathogen: Babesia microti (most likely) |
| Tick vector: Ixodes scapularis |
| Geographic distribution: Northeastern region and upper-midwestern states |
| Classic presentation: Fever, fatigue, malaise, headache, myalgia, arthralgia, nausea, anorexia, cough, hemolytic anemia, thrombocytopenia, leukopenia, elevated aminotransferase levels |
| Diagnosis: Babesia microti intraerythrocytic ring form (trophozoites) or merozoites in tetrads (Maltese cross) identified on Giemsa- or Wright-stained peripheral smear; polymerase chain reaction assay; serology |
| Treatment: Atovaquone with azithromycin for mild to moderate disease and clindamycin with quinine for severe disease; consider exchange transfusion in severe disease; typical treatment course is 7-10 days and at least 6 weeks in highly immunocompromised patients |