149 Gastrointestinal Pathogen Distribution for Patients With Immunosuppressive States and Acute Diarrheal Illness

Abstract

INTRODUCTION: Up until recently, identification of gastrointestinal (GI) pathogens in patients with an acute diarrheal illness (ADI) was limited. The introduction of a new GI pathogen PCR panel now offers a quick, reliable way to identify specific GI pathogens. It has been established that patients with immunosuppressive states are more susceptible to opportunistic GI pathogens, but the prevalence of these pathogens remains unknown. This study aims to compare the pathogen distribution in ADI in patients with immunosuppressive states versus patients without immunosuppressive states. METHODS: A database of patients was identified who presented to Montefiore Medical Center with an ADI and a positive GI pathogen PCR panel from April 2018 to November, 2018. Data collected included patient demographics, toxic habits, and previous antibiotic and steroid use within 6 months prior to the ADI. Immunosuppressed patients were identified as having either HIV/AIDS, organ transplant, active hematologic malignancy, primary immunodeficiency disease or current use of immunosuppressive medications. If C. difficile was identified, the patient was included if a confirmatory C. difficile test was positive. The primary outcome was the pathogen identified on GI pathogen PCR panel. RESULTS: Of 551 patients identified for this study, 130 patients (23.6% of the cohort) were immunosuppressed. A total of 88 patients had a positive GI pathogen PCR panel for C. difficile and 472 patients had a positive GI pathogen PCR panel for organisms other than C. difficile. The most common pathogen in both the non-immunosuppressed and the immunosuppressed patients was Enteropathogenic E. coli (EPEC) (184 cases, 35.3% and 26.9%). The most common viral pathogen was Norovirus (47 cases, 6.6% and 14.6%), and the most common parasitic pathogen was Giardia lamblia (21 cases, 2.4% and 8.5%). Immunosuppressed patients were more likely to be positive for Norovirus (14.6% vs. 6.6%, P = 0.008), Cryptosporidium (5.4% vs. 0.7%, P = 0.002), Giardia (8.5% vs. 2.4%, P = 0.004), Enteroinvasive E. coli (EIEC) (13.1% vs. 4.5%, P = 0.001) and C. difficile (23.1% vs. 13.7%, P = 0.011). No other differences in pathogen distribution were identified between the two groups. CONCLUSION: Patients presenting with ADI with immunosuppressive states were more likely to have Norovirus, Giardia, Cryptosporidium, EIEC or C. difficile identified on GI pathogen PCR panel. Further studies are needed to better define these findings and their clinical implications.