1405. Infectious Causes of Chronic Meningitis in HIV-Negative Patients: A Case Series

BACKGROUND: Chronic meningitis can be defined as inflammation of the cerebrospinal fluid (CSF) with the presence of >5 white blood cells/mm(3) of CSF for 4 weeks. There is little literature available on defining the infectious causes or risk factors of chronic meningitis, and there are no studies that have looked at mortality in this group of patients. Our aim for this study was to evaluate the epidemiology, risk factors, and mortality of infectious causes of chronic meningitis within our healthcare system. METHODS: A total of 59 cases were identified through a systematic retrospective review from our electronic medical record database from 2004 to 2018 and were identified by having the presence of two consecutive lumbar punctures with a white blood cell count in CSF >5 WBC/mL(3) in a 4-week period, or by having 4 weeks of meningeal symptoms with one lumbar puncture with >5 WBC/mL(3). All cases were manually reviewed. We excluded patients with diagnosis of human immunodeficiency virus (HIV) infection. We included a review of comorbidities that could impair the immune system such as diabetes mellitus, alcohol use, chronic kidney disease (CKD) stage III or greater use of chemotherapy, immunotherapy, or chronic use of steroids and previous transplant recipients. The study was approved by the institutional review board RESULTS: 59 cases of chronic meningitis attributable to an infectious etiology were identified. The most common pathogens were Borrelia burgdorferi (37%), Cryptococcus sp. (27%), and Candida sp. (10%). Other etiologies which were less common included viral etiologies (13%). Finally, there were two cases secondary to Streptococcus pneumonia. Regarding the total number of patients with the comorbidities studied, 13 (22%) had diabetes, 12 (20%) had CKD, 12 (20%) were under some form of chemo/immunotherapy including chronic steroid use and 3 (5%) of patients were transplant recipients. CONCLUSION: Our study identified common infectious pathogens causing chronic meningitis in a rural, HIV-negative population. Our findings indicate that cryptococcus should be considered even within HIV-negative individuals, and Lyme disease should be considered in all endemic areas. Mortality was significant among patient with cryptococcal meningitis, where patients with Lyme meningitis did very well. [Image: see text] DISCLOSURES: All authors: No reported disclosures.