[Occurrence of Borrelia antibodies in field hares (Lepus europaeus)]

Using the indirect haemagglutination reaction with an antigenic extract from Borrelia recurrentis, the author assessed in the hare the incidence of Borrelia antibodies, incl. antibodies against Borrelia burgdorferi, the causal agent of Lyme borreliosis, a multisystemic disease with natural foci, a disease transmitted mostly by ticks of the genus Ixodes. Sera of 113 hares from 11 localities in the CSSR examined by this method reacted in 41.6% by titres within the range from 1 : 16 to 1 : 512, only 26.5% sera reacted by titres of 1 : 64 and more. Positive values were recorded throughout the year with a maximum in the summer months, there was no age dependence, the incidence was more frequent in adults than juveniles (28.04% and 22.2% resp.). The mean positivity of the three most frequent localities was 28%, with a variation of +/- 5.3%. Despite the hitherto not proved incidence of Borrelia in positive subjects we may assume, based on crossed reactivity of Borrelia recurrentis and Borrelia burgdorferi and analogously with North American representatives of the hare family, the presence of this infectious agent also in the field hare.