The Frequency of Abortion Caused by Chlamydia abortus in Aborted Fetuses of Sheep and Goats in Iran

Background: Chlamydia abortus, is one of the most important causes of abortion in small ruminants. Evaluating the frequency of chlamydial infection in abortion of animals is beneficial in epidemiological surveys. The purpose of the present study is to determine the frequency of abortion caused by Chlamydia abortus using PCR method. Methods: A total of 200 fetuses were collected from 150 ewes and 50 does. The samples were collected from abomasal contents and lungs of the fetuses and using PMP gene of Chlamydia abortus, PCR was conducted. The infection occurrence with regard to the species of animals, age, gender and type of pregnancy along with age, numbers of pregnancy and numbers of abortion in the aborted animals were statistically analyzed by Chi-squared test, t-test and Spearman correlation coefficient which all were calculated using SPSS version 25. Results: The bacterium DNA was detected in 47 fetuses. The infection occurrence didn’t have significant statistical relationships with the species, age and gender of the fetuses. Chlamydial infection in the twin fetuses was significantly more than the single ones. The infection had statistical relationship with ages and parturition numbers of the aborted animals but not with the numbers of abortion. Conclusion: Regarding the high frequency of abortion caused by Chlamydia abortus in this study (23.5%), it is necessary to boost the information about the prevalence of Chlamydia abortus in different regions of our country