Seroprevalence of Central European ticks in the Lorraine region

BACKGROUND: Central European encephalitis, caused by the tickborne encephal itis virus (TBEV), is exceptional in France Most cases have been described in Alsace. As 2 cases of tick-borne encephalitis were diagnosed in the Nanc y region, a seroepidemiological survey was conducted in the Lorraine region (Meurthe & Moselle, Moselle, Vosges, Meuse) in 1996. METHODS: The survey was proposed to approximately 1,000 persons attending p reventive medicine clinics. The subjects were asked to fill out a self-admi nistered questionnaire on factors related to tick bite exposure and underwe nt TBEV serology tests. RESULTS: 1,177 subjects participated in the survey Half of them lived in ru ral areas, 91% had occasional or regular contact with the forest environmen t and 21% had experienced tick bites. TBEV serology (Igc) was positive in 1 9 subjects (1.6%; 95%CI: 0.9%-2.3%); 9 sera were positive on Western blot ( 0.76). No IgM positive serum was found. Seroprevalence was higher in subjec ts with a past history of tick bites compared with the others (2.9% vs 1.3% , p = 0.074). CONCLUSION: The low seroprevalence of TBEV in this survey is not in favor o f widespread tick-bite encephalitis virus in the Lorraine general populatio n.