SEROLOGICAL DIAGNOSIS OF LYME BORRELIOSIS - DEVELOPMENT AND VALIDATION OF A TEST SYSTEM FOR EPIDEMIOLOGIC INVESTIGATIONS IN DOGS

The aim of the study was to develope and validate a serological test s ystem for extended epidemiological investigations to which extend dogs were exposed to Borrelia burgdorferi. For this purpose, 121 samples o f dogs which were suspect of an infection and submitted to the laborat ory for serological testing, were investigated in an immunofluorescenc e test (IFT) and to different enzyme-linked immunosorbent assays (ELIS A). Valuation of the ELISA systems was assessed in relation to the IFT . Sensitivity, specificity and predictive values were calculated for n egative, positive and also borderline values. In the screening test al l samples with a positive titre in IFT were judged positive. Samples n egative in IFT showed negative results in the screening in only 86 %. All samples positive in screening or of borderline value in IFT were a gain tested using a confirmatory ELISA. By this procedure a specificit y of 100 % and a sensitivity of 85 % was calculated for samples with p ositive or negative IFT titres, respectively. Samples with IFT borderl ine titres (1:64 or 1:128) were judged negative in this ELISA in 80 % and borderline in 16 %. Checking of selected samples in an immunodot t est cnfirmed the ELISA results. Sera being negative in ELISA showed al so no specific reaction in this test. When considering the possibility of false positive reactions in IFT, rather high percentages of sensit ivity and specificity could be found. Because all real positive sample s could be detected using the confirmatory ELISA as a single test, the re is no further need in epidemiological investigations to use the scr eening test. For specific problems the Western blot can be used. Thus, for serological testing of Borreliosis a low-budget and safe test sys tem is available, and the investigation of random samples in an extend ed area can be started to estimate the geographical distribution of Bo rrelia burgdorferi.