Spread of early-summer meningoencephalitis in the Federal Republic of Germany

Abstract

Between 1978 and 1984 there were 299 serologically confirmed cases of tick-borne encephalitis in the Federal Republic of Germany (180 males, 119 females; aged 1-82 years). A previous tick bite was recalled by 258 (86.2%). The illness had taken the form of a feverish infection in 13, meningitis in 161, meningoencephalitis in 13, and meningomyeloencephalitis in 14. There were three deaths (1%), and permanent neurological sequelae in 20 (7%). The incidence of new cases cases between April and October varied from eight to 118 per year. The Federal Republic of Germany (FRG) was the place of infection in 239, other European countries in 52 (42 in Austria). In the FRG the disease occurred predominantly in Bavaria (156), half of the cases in Lower Bavaria and eastern and northern Upper Bavaria and in Baden-Württemberg (78), concentrated in the regions around Freiburg and Karlsruhe, a few (3) in Hessen and Rhineland-Palatinate (2). No cases were noted in other parts of the FRG. Antibody studies on 8526 persons in the endemic regions of Bavaria and Baden-Württemberg produced rates of 2.0 and 1.2%, respectively. The rate increased with age, to a peak of 2.4% in the seventh decade. Those working in forestry and agriculture had a higher antibody rate, at 4.6 and 3.3% respectively, than civil servants, employees and housewives (0.4-0.9%). In some areas the antibody rate varied from less than 1 to 6%. Those with higher antibody rates also had higher infection rates, and vice versa.