Detection of Chlamydophila abortus in sheep (Ovis aries) in Mexico

Chlamydophila abortus is one of the pathogens which induce abortion in small ruminants; this pathogen has a tropism for ruminant placenta and causes the disease commonly referred to as Ovine Enzootic Abortion (OEA). In Europe are estimated economic losses of around 20 million pounds a year by OEA. In the American Continent the disease has been reported only in Canada, the United States, Colombia and Chile while in Mexico it is unknown whether OEA is common and it is causing abortions in flocks of sheep from "Estado de Mexico". The objective of this study was investigating the prevalence of anti-Chlamydophila abortus IgG antibodies and detection of C. abortus DNA in sheep with clinical abort history by mean of ELISA assay (C. abortus ELISA, Institute Pourquier, Montpellier, France) and molecular identification of the principal outer membrane protein (POMP 90-91B) gene by PCR, respectively. A cross-sectional study was carried out to enroll and random sample of ewes from november 2003 until march 2005. A total of 349 sera and vaginal swabs samples were collected from 35 flocks of sheep from Xalatlaco. The results showed that the seropositive rate was 31.1% (14/45) for healthy and 21.3% (65/304) for sheep with history clinical of abort. In vaginal swabs, the PCR showed 0% (0/45) for healthy animals and 0.65% (2/304) for aborted sheep. Samples from the lungs and liver of the fetus of one of these animals were also positive for C. abortus. In conclusion, these results confirmed that infection with C. abortus is common and is affecting sheep flocks in the Mexican highlands. Therefore, is necessary that the authorities responsible for animal welfare in Mexico (SAGARPA) to set up appropriate epidemiological surveillance and control programs to eradicate this disease.