Background: Q fever is a health problem affecting humans and animals worldwide. In Poland, previous studies have pointed to 2 sources of outbreaks of the disease: the importation of infected animals and their products, and natural domestic foci. In the last decade, 5 outbreaks have occurred in cattle farms in south Poland in Malopolskie, Podkarpackie, Opolskie, and Silesian provinces. The aim of this study was to characterize the Q fever foci in Poland.
Material and methods: A total of 279 individuals were included. Levels of serum IgM and IgG antibodies to phase I and II C. burnetii antigens were assayed by indirect immunofluorescence method. Bacterial DNA from all specimens were detected with PCR with primer pairs specific to the htpAB-associated repetitive element, and amplicons were sequenced.
Results: Infection was recognized in 67 individuals out of 279 tested in all foci. Twenty-five individuals presented clinical symptoms of acute Q fever. DNA of C. burnetii was found in 8 human blood samples obtained from 3 farm workers and 5 family members.
Conclusions: The described outbreaks demonstrate that the main source of human infections in Poland is infected cattle.