338. Analysis of Etiologies of Aseptic Meningitis within a Nation-Wide Hospital Network

Background Aseptic meningitis can be caused by an array of microorganisms, both bacterial and non-bacterial, as well as non-infectious conditions. Some etiologies of aseptic meningitis require treatment with antibiotics, antiviral, antifungals, anti-parasitic agents, immunosuppressants, and or chemotherapy. There are limited diagnostic tools for diagnosing certain types of aseptic meningitis, therefore knowing the differential causes of aseptic meningitis, and their relative percentages may assist in diagnosis. Review of the literature reveals that there are no recent studies of etiologies of aseptic meningitis in the United States (US). This is an epidemiologic study to delineate etiologies of aseptic meningitis in a large database of 185 HCA hospitals across the US. Methods Data was collected from January 2016 to December 2019 on all patients diagnosed with meningitis. CSF PCR studies, and CSF antibody tests were then selected for inclusion. Results Total number of encounters were 3,149 hospitalizations. Total number of individual labs analyzed was 10,613, and of these 262 etiologies were identified. 23.6% (62) of cases were due to enterovirus, 18.7% (49) due to HSV-2, 14.5% (38) due to West Nile virus, 13.7% (36) due to Varicella zoster (VZV), 10.5% (27) due to Cryptococcus. Additionally, we analyzed the rate of positive test results by region. Nationally, 9.7% of tests ordered for enterovirus were positive. In contrast, 0.5% of tests ordered for HSV 1 were positive. The southeastern United States had the highest rate of positive tests for HSV 2 (7% of tests ordered for HSV 2 were positive). The central United States had the highest rate of positive test for West Nile virus (11% of tests ordered for West Nile were positive). The northeastern region and the highest rate of positive tests for varicella zoster (18%). Table 1: Percentage of positive CSF tests (positive tests/tests ordered) Table 2: Lists the number of HIV patients and transplant patients that had positive CSF PCR/serologies Figure 1: Percentage of positive CSF tests in each region Conclusion Approximately 40% of aseptic meningitis population had treatable etiologies. A third of the Cryptococcus meningitis population had HIV. Furthermore, enteroviruses had the majority of cases within the US, which are similar to studies done in other parts of the world. Disclosures All Authors: No reported disclosures