Interpretation

A positive result indicates the presence of Babesia species DNA and is consistent with active or recent infection. While positive results are highly specific indicators of disease, they should be correlated with blood smear microscopy, serological results, and clinical findings.

A negative result indicates absence of detectable DNA from Babesia species in the specimen but does not always rule out ongoing babesiosis in a seropositive person since the parasitemia may be present at a very low level or may be sporadic.

Other tests to consider in the evaluation of a patient presenting with an acute febrile illness following tick exposure include serologic tests for Lyme disease (Borrelia burgdorferi) and molecular detection (polymerase chain reaction: PCR) for ehrlichiosis/anaplasmosis. For patients who are past the acute stage of infection, serologic tests for these organisms should be ordered prior to PCR testing.