An Unusual Case of Listeria monocytogenes in the Midst of a Community Outbreak

1. An Unusual Case of Listeria monocytogenes in the Midst of a Community Outbreak Introduction Greg Burfeind MS31, Mark Reid MD2 1University of Colorado School of Medicine, Aurora, CO 2Denver Health Medical Center, Denver CO Listeria monocytogenes is a known but rare cause of spontaneous bacterial peritonitis (SBP). L. monocytogenes is a well-known pathogen in pregnant females, neonates, elderly, and immunocompromised individuals. Commonly attributed to ingestion of unpasteurized milk products, soft cheeses, and deli meats. Patients with impaired T-cell-mediated immunity, such as patients with HIV, are especially prone to infections caused by L. monocytogenes. Common disease manifestations of L. monocytogenes include febrile gastroenteritis, meningitis, and sepsis. It is important to consider Listeria monocytogenes in patients with SBP due to its high mortality rates and lack of susceptibility to empiric third-generation cephalosporin treatment make in SBP.2 The presence of gram positive bacilli on a gram stain of ascitic fluid suggests the diagnosis of listeria SBP. This case illustrates the importance of considering L. moncytogenes as a causative agent of SBP in immunocompromised patients, especially in the setting of a recent community outbreak. References 1. Centers for Disease Control and Prevention. Investigation Update: Multistate Outbreak of Listeriosis Linked to Whole Cantaloupes from Jensen Farms, Colorado. Available at: http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/index.html. Accessed December 6, 2011. 2. Frachtman S, Lu L, Lau M, Greensberg S. Spontaneous Bacterial Peritonitis Due to Listeria monocytogenes: A Case Report and a Review of Listeria monocytogenes Peritonitis. Infectious Diseases in Clinical Practice. Vol 17, Number 1, Jan 2009: 63 – 65. 50-year-old HIV positive male with cirrhosis caused by hepatitis C and chronic alcohol abuse presents with two-day history of abdominal distention, weakness, and decreased oral intake. No fever, chills, abdominal pain, nausea or vomiting. Physical exam: temperature: 38.7oC; heart rate: 112 beats/min; blood pressure: 148/88; respiratory rate: 24 breaths/min. Abdomen distended, firm and mildly tender to palpation. Paracentesis: 18,140 white blood cells/mm3, with 91% neutrophils (ascites neutrophil count of 16,507/mm3). Started intravenous levofloxacin for empiric treatment of SBP. Gram stain of ascitic fluid revealed gram-positive bacilli. Antibiotic coverage was immediately changed to intravenous ampicillin and vancomycin to cover for gram-positive organisms. The organism from the ascitic fluid cultures wass identified as L. monocytogenes. The patient received a two-week course of intravenous ampicillin and recovered completely. The described case of L. monoytogenes SBP occurred shortly after the peak of a local and national outbreak of L. monocytogenes traced back to cantaloupe from Jensen Farms in Granada, CO. Discussion As of November 1, 2011, 139 cases of listeriosis from 28 states, including 8 deaths in Colorado, had been reported to the CDC.1 Case Conclusions Background