Pulmonary Mycobacterium bovis Infection: Uncommon Modes of Transmission

Abstract

SESSION TITLE: Student/Resident Case Report Poster - Chest Infections II SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Tumor necrosis factor (TNF) blockers are being used increasingly in the management of inflammatory bowel disease, especially Crohn’s disease. We present a case of pulmonary Mycobacterium bovis infection in a patient treated with Adalimumab, and subsequently with Infliximab. CASE PRESENTATION: A 19 year old woman with a history of Crohn’s disease was admitted because of fevers and dry cough for 3 days. She had fever of 103°C with generalized weakness, chills and sweating. She had been started on Infliximab 2 weeks prior to the presentation. Her other medications included azathioprine and 6 mercaptopurine. She had been previously treated with Adalimumab. She had recently travelled to Los Angeles, but denied consuming any unpasteurized milk products. She denied any animal contact in the recent past.. She was found to have bibasal lung nodules on a prior abdominal CT scan. Chest CT revelaed extensive small bilateral nodules, and scattered tree- in-bud appearance, raising the concern of mycobacterial disease. In view of negative acid-fast bacilli smears of sputum and a positive interferon gamma release assay, pulmonary wedge biopsy was obtained which revealed granulomata with caseous necrosis and acid-fast bacilli. Organisms were subsequently speciated as Mycobacterium bovis. Her treatment was complicated by Isoniazid induced elevation of liver function tests and pancreatitis, eventually requiring a modification in the treatment regimen to include Moxifloxacin, Ethambutol and Rifampin. The patient was discharged home with appointments for pulmonary, infectious disease and gastroenterology follow up. DISCUSSION: Mycobacterium bovis infection may be acquired through different modes of transmission, the most common being animal to human via consumption of unpasteurized milk or milk products (1). However human to human transmission has been reported, which is influenced by host and environmental factors (2). Adalimumab and infliximab induced suppression of phagosome maturation plays a factor in the pathogenesis of M. bovis infection. (3) CONCLUSIONS: TNF blockers can increase the risk of Mycobacterium bovis infection acquired secondary to other uncommon modes of transmission such as aerosolized animal to human and human to human transmission in susceptible host. Reference #1: Centers for Disease Control and Prevention (CDC. “Human tuberculosis caused by Mycobacterium bovis--New York City, 2001-2004.” MMWR. Morbidity and mortality weekly report 54.24 (2005): 605. Reference #2: Evans, Jason T., et al. “Cluster of human tuberculosis caused by Mycobacterium bovis: evidence for person-to-person transmission in the UK.”The Lancet 369.9569 (2007): 1270-1276. Reference #3: Harris, James, Jayne C. Hope, and Joseph Keane. “Tumor necrosis factor blockers influence macrophage responses to Mycobacterium tuberculosis.”Journal of Infectious Diseases 198.12 (2008): 1842-1850. DISCLOSURE: The following authors have nothing to disclose: Mangalore Amith Shenoy, Selma Demir, Pavan Gorukanti, Pavan Irukulla, Amit Agarwal, Prarthna Chandar, Ishan Malhotra, Kabu Chawla, William Pascal No Product/Research Disclosure Information