Psittacosis associated with exposure to equine foetal membranes

Psittacosis, also known as ornithosis, is a systemic infectious disease caused by Chlamydophila psittaci. It is characterised by fever, malaise, cough, myalgias and atypical pneumonia. Complications include myocarditis, endocarditis, hepatitis, disseminated intravascular coagulation reactive arthritis, and neurological abnormalities including cranial nerve palsy and meningitis. In November 2014, four cases of respiratory illness among staff and students at a veterinary school were reported to Health Protection NSW by the veterinary school through the Department of Primary Industries. The affected staff worked in the veterinary reproduction unit where the students were undertaking a veterinary reproduction rotation at the time. Active case finding, through notices at the university and interviewing of cases, identified a further case of atypical pneumonia at a local stud farm, where one of the students had worked. Through this outlier, a common exposure to the equine foetal membranes of a single mare, amongst all the cases, was established, generating the hypothesis that the membranes of this mare was the source of the outbreak. The foetal membranes subsequently tested RT-PCR positive for C. psittaci.