Value of PCR, Serology, and Blood Smears for Human Granulocytic Anaplasmosis Diagnosis, France.

We prospectively examined the effectiveness of diagnostic tests for anaplasmosis using patients with suspected diagnoses in France. PCR (sensitivity 0.74, specificity 1) was the best-suited test. Serology had a lower specificity but higher sensitivity when testing acute and convalescent samples. PCR and serology should be used in combination for anaplasmosis diagnosis.