Prevalence of antibodies to Coxiella burnetii among farming population in eastern Poland.

The presence of blood serum antibodies to Coxiella burnetii phase I antigen, indicative of chronic Q fever or convalescence, was found by indirect immuno-fluorescent test in 16 out of 90 examined farmers (17.8 %) living in the Lublin region (eastern Poland) and in none of 30 examined urban blood donors living in the city of Lublin (p < 0.05). In both groups no antibodies to C. burnetii phase II antigen, indicative of acute Q fever, were detected. The frequency of antibodies among farmers was greater in females than in males (26.1 % versus 9.1 %, p < 0.05) and was significantly dependent on age ( xi(2) = 146.42, p < 0.000001) being greatest in the subgroup of farmers aged 41-55 (38.5 %) while no positive reactions were found in young and elderly farmers (respectively, equal to or below 25 and above 56 years). The results suggest that the examined agricultural region could be in the past an epidemic area of Q fever, probably before 15-30 years.