[Coxiella burnetii infections (Q fever) in animals and humans in Poznan and Leszno districts detected by serodiagnosis]. / Zakazenia Coxiella burnetii (Goraczka Q) u zwierszat i ludzi w województwach leszczynskim i poznanskim rozpoznane w badaniach serologicznych.

In Poznan and Leszno districts, serological survey of Q fever among cattle and sheep have been performed since 1973. Coxiella burnetii infections have not been detected until 1985. During this period 28,272 blood samples derived from cattle and sheep have been tested. For the first time in Poznan district, seropositive cattle were found in 1986 (5.5%). In the next year percentage increased to 16.3% and in following years has been on similar level. In Leszno district, serum antibodies to C. burnetii were detected in cattle in 1988 (25.9% seropositives). On the consecutive years, percentage of seropositive animals has decreased and in 1991 was 3.2% only. During these years there were 2.3 and 8.3% seropositive sheep detected in Poznan and Leszno districts respectively. Serological survey of C. burnetii infection has been performed among people exposed to this agent occupationally who undergo intermittent obligatory testing for brucellosis. In Leszno district among 4214 persons tested, 34.4% were seropositive. In Poznan district from 1988 to 1991 antibodies to C. burnetii have been detected in 22.7% of 6396 people tested. From year to year the percentage of seropositives fluctuated from 16.6 to 34.7%.

Epidemic of Q fever in Leszno district in Poland.

In 1988 an epidemic of Q fever was detected in Leszno district. During 1973-1985 all 28,066 cattle tested for C. burnetii antibodies were found to be negative. The first seroconversions were found in cows which produced stillborn young. In the following years the number of seropositive cattle increased from 8.4% in 1987 to 21.6% in 1989. In 1988 all animal workers in the district were tested for C. burnetii antibodies. Of 4,264 persons tested, 1,451 (34%) were seropositive. A detailed study of workers and animals on one farm were performed. A herd of animals was found to be seropositive (32.1%), 68% of workers in direct contact with infected animals were seropositive and 29% of persons drinking raw milk. C. burnetii strains have been isolated from ticks, wild animals and birds hunted in close proximity of the farm. The dynamics of C. burnetii infection among animals and humans in this district and the fact that there is no importation of animal herds suggests that the possible route of introduction of Q fever in this area may be with imported semen or breeding bulls. The presence of C. burnetii in ticks and wild animals indicates the transfer of Q fever to the natural environment and its maintenance in this territory.