214. Comparison of Clinical and Laboratory Findings of Human Monocytic Ehrlichiosis (HME) and Human Granulocytic Anaplasmosis (HGA) in Long Island, New York.

BACKGROUND: Suffolk County reports to the Department of Health the highest absolute number of cases of tick-borne diseases (TBD) for NY State. While Lyme disease and Babesiosis are the most common TBD in this county with more than 600 and 100 cases reported every year, respectively; two other TBD, HME (due to Ehrlichia chaffeensis) and HGA (due to Anaplasma phagocytophilum) are also commonly reported in this county (63 and 37 every year, respectively). There is limited data directly comparing both diseases on acute presentation; the aim of this study was to compare the clinical features, laboratory findings and complications of HME and HGA in the epicenter of TBD in NY State. METHODS: A retrospective study was designed to collect cases with the diagnosis of HME and HGA by using ICD9 or ICD10 codes from 2013 to 2018 at Stony Brook Medicine. Inclusion criteria were patients 18 years or older who had a positive PCR in blood for E. chaffeensis or A. phagocytophilum. Demographics, clinical features, laboratory results, and complications were extracted from patient charts. We used the chi-square test to compare the proportion of symptoms and a two-tailed unpaired student T-test to compare laboratory values. RESULTS: A total of 40 cases of HME (mean age 67 ± 13) and 27 with HGA (mean age 63 ± 12) met inclusion criteria. Only approximately 50% of cases had a documented history of tick exposure. Clinical presentations were similar in terms of frequency of fever, headache, arthralgia, and myalgia. In contrast, hypotension, confusion, and rash were more common in HME although only the latter was significantly more common. HME patients had significantly greater degrees of leukopenia and thrombocytopenia and elevated AST levels. The majority of patients with HME and HGA were hospitalized >1 day for management of their acute illness (HME, 30/40 and HGA 17/27). Several patients with HME had gastrointestinal (GI) complications including 3 with acute acalculous cholecystitis, 1 with duodenitis, and 1 with acute colitis; 1 patient with HGA had perforated diverticulitis. CONCLUSION: Patients with acute HME tend to be more ill than those with acute HGA; however, a substantial proportion of both groups require hospitalization. GI complications were more commonly seen in HME (12.5%) than HGA (3.7%) which deserves further investigation. [Image: see text] DISCLOSURES: All authors: No reported disclosures.