Excretion of Coxiella burnetii through milk of cows as risk to human health

Abstract

Coxiella burnetii is the causative agent of very important zoonoses. Transmission of infection to humans occurs mainly by domestic ruminants that excrete cthe ausative agent with faeces, urine, lochia, placenta and milk. Of all these routes, the longest lasting is the excretion through milk, which can be over several lactations. In this paper, the dynamics of excretion of C. burnetii through milk in seropositive cows and the level of immunoglobulin G in milk serum were examined. Correlation between these two parameters was also examined. A PCR method was used for determination of C. burnetii genome and RID plates - for the concentration of immunoglobulin. The excretion of the causative agent through milk differed between different stages of lactation, being the lowest in the first phase (16.6%) and the highest in the second phase (80.0%) when the lowest concentration of immunoglobulin G in milk serum (4.0 g) was detected.