347. Capnocytophaga canimorsus Meningitis: Diagnosis Using Polymerase Chain Reaction Testing and Systematic Review of the Literature

Abstract

Background Capnocytophaga canimorsus is associated with sepsis following dog bites especially in asplenic patients. Meningitis is a rare entity and may be associated with delayed diagnosis due to poor or delayed growth. We provide our experience using polymerase chain reaction (PCR) to establish the diagnosis and performed a comprehensive review of C. canimorsus meningitis providing data on clinical manifestations, diagnosis, and outcomes of this unusual infection.MethodsA systematic review of the peer-reviewed English literature (PubMed, Embase, Ovid Medline) from January 1966 to March 2018 was performed to identify cases of C. canimorsus meningitis in addition to our case. Data collected included demographics, risk factors, cerebrospinal fluid (CSF) findings, PCR testing, treatment, and outcomes. Descriptive statistics are presented as numbers (percentages) and medians (ranges).ResultsA total of 37 cases with a median age of 63.5 years (range 12 days–83 years) with a male predominance (75%). A relatively low proportion had an immunocompromised state: 17% splenectomy and 6% steroid use. The most common risk factor was alcoholism (19%). Sixty-four percent reported a dog bite (all <10 days prior to presentation); 22% non-bite dog exposure; 3% cat bite; and 11% no animal contact. CSF mean white cells of 1,894 cells/mm3, neutrophils 76% (±19%), protein of 225 mg/dL (±149), and glucose CSF/serum ratio of 0.24 (±0.15). In 16 (43%) cases, blood cultures were positive for C. canimorsus (median 4.3 days) and 27 (73%) had positive CSF cultures (median 4.4 days). PCR established the diagnosis in seven (19%) cases. Antibiotic therapy was given for a median of 14 days (range 7–42 days). Prognosis was overall favorable with one (3%) mortality; 19% of survivors had sequelae: four hearing loss, one headaches, two neurological deficits, and two with extremity amputations.Conclusion C. canimorsus meningitis is a rare clinical entity occurring in patients of all ages typically after dog exposure. While classically considered a disease of immunocompromised patients, most cases occurred in previously healthy, immunocompetent persons. Diagnosis may be established by PCR and testing should be considered in culture-negative cases with associated risk factors. Outcome was generally favorable after a median antibiotic duration of 14 days.Disclosures All authors: No reported disclosures.