562: A RARE CASE OF LISTERIA MONOCYTOGENES PRESENTING AS SEPTIC SHOCK

Abstract

Introduction: Listeria Monocytogenes (L. Monocytogenes) is a gram-positive intracellular bacterium that enters the host by ingestion of contaminated foods. Listeriosis is challenging to diagnose, however diagnosis is crucial given the mortality rate in severe disease. We describe a case of a 26-year-old pregnant female who presented to the hospital in shock secondary to L. Monocytogenes bacteremia. Description: 26-year-old Hispanic female, 18 weeks pregnant, presented with fevers, right flank pain, nausea, and vomiting. Vitals on admission were: temperature 104.7 °F, BP 86/49 mmHg, HR 140s, and RR 40s. She was started on Vancomycin, Cefepime, and Metronidazole. Despite 4 Liters of IV fluids, she remained hemodynamically unstable, requiring admission to the medical ICU for inotropic support. Labs were notable for hyponatremia (130), transaminitis (AST 80, ALT 93), normal WBC (10.9) with significant bandemia (26%). Urine analysis was negative. Ultrasound abdomen showed renal fullness. Azithromycin, Ampicillin, and Acyclovir were added empirically. After 24 hours, blood cultures became positive for gram-positive bacilli, and ultimately L. Monocytogenes was identified in multiple specimens. Ampicillin was continued and patients hemodynamics improved. Discussion: L. Monocytogenes is an intracellular pathogen that initially encounters the gut mucosa and invades the blood and lymphatic system, traveling directly between cells, thus avoiding T-cell immunity, complement, and antibodies. Listeriosis has an annual incidence of 2.4 per 1 million in the US, most commonly affecting the elderly, pregnant women, neonates, and immunocompromised individuals. Pregnant women have a 16-18-fold increased risk of infection, and pregnant Hispanic women are at 24 times increased risk. Noninvasive listeriosis is often self-limiting, and may be associated with nonspecific symptoms like diarrhea, fever, myalgias, and headaches. Invasive listeriosis, on the other hand, has a mortality rate of 20-30% and can cause septicemia, meningitis, and in pregnancy, miscarriage, or stillbirth. L. Monocytogenes, although rare, has severe implications for both mother and fetus. In addition to the obstetrics population, critical care providers must have a high index of suspicion to prevent, diagnose, and treat patients for L. Monocytogenes.