Seroprevalence of Chlamydia abortus in cattle and its association with abortion

Chlamydia abortus (C. abortus) is a Gram-negative, obligate intracellular bacterium causing enzootic abortions, especially in small ruminants. Due to its zoonotic potential, it is an important pathogen that threatens reproductive health in both animals and humans. It has been reported that C. abortus can cause abortion, stillbirth and underweight offspring in ruminants and can cause infection in cattle; however, epidemiological data on this subject are limited. This study was carried out to determine the seroprevalence of C. abortus infection in cattle and to evaluate the relationship between infection and abortion cases. A total of 200 cattle blood samples (100 aborted and 100 healthy) collected from Central Anatolia were analysed by the ELISA method. According to ELISA results, 13% of aborted cows and 2% of healthy cows were seropositive, and the difference between the groups was statistically significant (p < 0.01). The total seropositivity rate was determined as 7.5%, and the antibody level was found to be mild or moderate in most of the positive samples. The findings indicate that C. abortus can cause infection in cattle and may be the causative agent in some abortion cases. The mostly subclinical course of the infection makes diagnosis difficult and poses a hidden threat to herd health. Therefore, identifying infected animals by serological screening is important for controlling the disease. In addition, due to its zoonotic effects, C. abortus should be carefully monitored in terms of both veterinary public health and human health.