The reported incidence of Lyme disease in Slovakia is indicative of the cyclic character of its appearance, which in the last 10 years rated 12.7/100,000 of the population with typically summer seasonality, prevalence (+20 %) in women, and relative high incidences in the 5-14 and 45-64 age groups. Early forms of the disease were manifested in 70 % of all reported cases. Geographically, the spread of the disease shows major differences in the number of cases reported in the individual districts. Antibodies persist long after the original attack, and there is a high incidence of antibodies in the healthy population in endemic areas. The presence of antibodies to B. burgdorferi antigens was proven in the serum of 250 blood donors by 3 different screening tests in 4.4-15.6 % of all persons, signifying different sensitivity as well as specificity levels. Subsequent immunoblot examination confirmed the presence of specific antibodies in 12.8 % of all persons, implying high exposure of the population in Slovakia to this infection, although it obviously proceeds in inapparent forms in the majority of cases (Tab. 2, Fig. 4, Ref. 14).