[Should ticks be regarded as a tularemia vector in habitants of North-Eastern Poland?]

A growing incidence of tick borne encephalitis and Lyme borreliosis in north-eastern Poland as well as an increasing number of Ixodes ricinus ticks in wooded areas and meadows have prompted the authors to evaluate the presence of antibodies against Francisella tularensis in serum of forest workers.

Sera of 820 persons, including 765 healthy forest workers (group I) and 55 patients with lymphadenopathy (group II) admitted to the Department of Infectious and Neuroinfectious Diseases, Medical Academy, Białystok, were diagnosed for antibodies against F. tularensis. Agglutination test at 37 degrees C, with suspensed F. tularensis (Biomed, Kraków, Poland) were used. Simultaneously all sera were tested for the presence of antibodies against B. burgdorferi, using ELISA test, Borrelia IgM and Borrelia IgG recombinant (Biomedica, Austria).

Of the 765 forest workers (group I), 20 (2.06%), persons showed positive (1:20) result of agglutination test, including 8 persons with antibodies against B. burgdorferi in IgG, of these 1 in IgM and IgG. Twenty persons with positive agglutination test had no signs of present or past tularemia in physical examination. Nine persons with prior diagnosis of arthritic form of Lyme boreliosis had undergone repeated antibiotic therapy (two 30-days therapy courses with cefotaksym or doxycycline). In group II, sera of 55 patients were negative in the agglutination test with F. tularensis.

The results of our study show that in North-Eastern Poland, Ixodes ricinus is not essential in Francisella tularensis transmission in this region.