CDC's surveillance category undetermined ehrlichiosis or anaplasmosis exists because the two diseases share clinical presentation, doxycycline treatment, and overlapping geography, but cross-reactive serology often cannot distinguish Anaplasma phagocytophilum from Ehrlichia chaffeensis on a single antibody titer. The bucket is a reporting compromise: clinically suspect, microbiologically ambiguous.
When a clinician suspects ehrlichiosis or anaplasmosis but the antibody titers are too cross-reactive to call, PCR on whole blood drawn…
Ehrlichia chaffeensis and Anaplasma phagocytophilum cause clinically similar diseases but parasitize different white blood cells.…
Ehrlichia chaffeensis ehrlichiosis classically presents with fever, headache, and a triad of laboratory findings: leukopenia,…
Ehrlichia ewingii ehrlichiosis was first recognized in human disease in 1999, almost exclusively in immunocompromised patients - HIV,…
Anaplasma phagocytophilum lives inside human neutrophils, where it forms cytoplasmic clumps called morulae visible on a Giemsa-stained…
A single tick species, Amblyomma americanum, transmits ehrlichiosis from Ehrlichia chaffeensis and E. ewingii, tularemia, Heartland virus,…