Bordetella bronchiseptica pneumonia in an HIV-positive animal care worker.

Bordetella bronchiseptica is a Gram-negative coccobacillary bacterium that causes respiratory tract disease in several mammalian species including kennel cough in dogs and snuffles in rabbits. Only in the past 20 years has this organism been implicated as a rare cause of human respiratory disease, most frequently as an agent of bronchopneumonia in immunocompromised patients such as those with malignant neoplasms and viral immunodeficiencies. B bronchiseptica is generally amenable to antimicrobial therapy, showing susceptibilities similar to other nonfermentative Gram-negative bacilli. We report the case of a 32-year-old HIV-positive female who presented to our institution with fever and chest pain of several days' duration. The patient had been diagnosed as HIV-positive 6 years previously and was on antiretroviral therapy. She was employed as a veterinary assistant. At the time of admission, the patient was diagnosed with oropharyngeal candidiasis, and a chest radiograph showed pulmonary infiltrates suggestive of bilateral pneumonia. She subsequently developed hypoxemia, and bronchoscopy was performed. Bacterial cultures obtained at the time of bronchoscopy yielded B bronchiseptica. Direct fluorescent assays for Pneumocystis carinii were also positive. Antimicrobial therapy was initiated, but the patient remained hypoxemic and tachycardic. She also developed pancytopenia. The patient was intubated and required ventilatory support for several weeks. She developed acute renal failure but did not require dialysis. Following the administration of large doses of steroids, the patient improved from a respiratory standpoint, was extubated, and was eventually discharged with follow-up scheduled in outpatient HIV clinic. This case illustrates the rare but clinically significant possibility of B bronchiseptica pneumonia in immunocompromised patients, particularly those with pets or occupational exposure to carrier animal species.

Elliot Carter, MD, and Andrea Kahn, MD. Department of Pathology, University of South Alabama, Mobile, AL.