Anaplasmosis is a tick-borne transmitted infection. Its clinical expression include fever, cytopenia and hepatitis.This infection was initially described in United States. In Europe, its epidemiology is not well known. Some isolated cases have been diagnosed in several country, were the tick Ixodes ricinus is known to transmitted another infection :the Lyme borreliosis.The purpose of our study is to look systematically for Anaplasmosis, in patient living in Eastern France, and presenting with compatible clinical symptoms using a new diagnosis tool : PCR in blood samples. So we will have new data about epidemiology in our country and the clinical symptoms that are associated with Anaplasmosis.

Inclusion Criteria:

• patient with at least one of following symptoms : fever or muscular pain or articular pain or respiratory signs or neurological signs or meningitis or erythema occurring during the three weeks after a tick bite-
• Or
• patient with fever with at least one of following criteria : thrombocytopenia, leucopenia, hepatitis, without any other cause that can explain these abnormalities.
• Or
• patient with tick-borne encephalitis, or primary stage Lyme borreliosis

Exclusion Criteria:

• children less that 10 years
• pregnancy
• patients with an other diagnosis that can explain clinical symptoms or biological abnormalities
• antibiotherapy with cyclins during the days before inclusion

patients with Anaplasma phagocytophilia