Background. Geographic differences of particular species of ticks and variant strains of Borrelias impede the comparison of local and foreign experience. The authors tried to support some literary observations with their own results and designed a study aimed at determination of anti-Borrelia antibodies (AB) in the selected population samples. The goal of the study was to find and statistically evaluate: a) difference in distribution of values of AB in the sample of probands from the risk and nonrisk environment (foresters in Šumava and Prague blood donors, respectively) by means of ELISA method, b) tick bite frequency in the risk and non-risk groups, c) to determine and statistically evaluate the prevalence of probands with increased levels of antiborrelial antibodies in the local study population by ELISA method and the prevalence of probands with non-normal values found by Western blot (WB) method. Methods and Results. In the group of Prague blood donors (control group), in total 200 probands were examined; in the risk group, 71 probands from Šumava forest were examined. Blood specimens were examined in the National Reference Laboratory for Lyme Borreliosis in Prague. In all specimens, ELISA NRLB KC90 was used. Western blot assay was used for confirmation. Conclusions. On the basis of literature review from Europe and USA, it is possible to generalize the following, despite some equivocations: 1. regional differences are not significant, with the exception of high-risk territories or „occupational exposure“; 2. there is no significant difference between males and females; 3. considerable caution is necessary in comparing the control and risk groups; prerequisite for such comparison is defining the characteristics of both groups.

        Key words: tick, borrelia strains, antiborrelial antibodies