Seroprevalence of antibodies to Coxiella burnetii among employees of the Veterinary University in Kosice, eastern Slovakia

Abstract

Coxiella burnetii is an obligate intracellular pathogen known to be the causative agent of Q fever, a zoonosis with worldwide occurrence. The organism has been found in many wild and domestic animals. Infected animals shed highly stable bacteria in urine, faeces, milk, and through placental and birth fluids. Humans acquire the infection mainly by inhaling infected aerosols, or by ingesting contaminated raw milk or fresh dairy products; tick transmission has been proven but is probably rare. The aim of the present study was to determine the titres of immunoglobulin IgG against phase I and II of C. burnetii, and to evaluate the risk factors that might be associated with exposure to C. burnetii among employees of the Veterinary University. Venous blood was obtained from 92 employees. IgG antibodies were determined by ELISA method modified in our laboratory using whole cells of the Nine Mile C. burnetii strain. The questionnaire was filled out by every subject to obtain epidemiological and clinical date. Phase I antibodies were detected in 35 subjects, i.e. in 38%, and phase II antibodies in 58 subjects, i.e. in 63%. When using the titre > or = 1:800 as a cut-off level, 2 samples were positive for phase I antibodies (2.1%) and 12 for phase II antibodies (13%). Factors predisposing to infection or exposure to C. burnetii included professional orientation and regular contact with farm animals and pets. Clinical history of some seropositive subjects revealed substantial problems, such as fever of unknown origin, rheumatic disease, disease of heart, liver, respiratory tract (particularly atypical pneumonia), chronic fatigue syndrome and spontaneous abortion in females. Q fever is a profession-related disease and prevention of its spreading within the risk population groups requires observation of basic safety rules.