Gestational psittacosis: case report and literature review

In Europe, Chlamydia psittaci is a relatively common cause of abortion in sheep and other mammals. Psittacosis in humans is typically described as a mild-to-moderate flu-like illness. If psittacosis is acquired during pregnancy, it can present as a severe, progressive, febrile illness, with headache, disseminated intravascular coagulation, abnormal liver enzyme studies, and impaired renal function. Only cases with significant fetomaternal morbidity and mortality have been reported. Recovery from this disease follows termination of pregnancy and appropriate antibiotic therapy. Direct exposure of gravid humans to infected products of conception is the most commonly reported mode of transmission. Diagnosis is suggested by the placental histopathologic findings, which consist of an intense, acute intervillositis, perivillous fibrin deposition with villous necrosis, and large irregular basophilic intracytoplasmic inclusions within the syncytiotrophoblast. Commercially available genus-specific monoclonal antichlamydial antibody is available for the rapid confirmation of the diagnosis. In the United States, only two cases of gestational psittacosis have been previously reported. In contrast to the experience in Europe, both cases were associated with psittacine birds. This is the first reported instance of ovine-related gestational psittacosis documented in the United States. Gravid patients should be warned to avoid contact with sheep and their products, particularly during the spring lambing period.