Meningitis due to group C Streptococcus: a case report and review of the literature.

Group C streptococci (GCS) are common causes of veterinary diseases and may colonize humans. Human diseases due to GCS are uncommon and generally occur in the elderly and persons exposed to animals or animal products. We report a case of Streptococcus equi subsp. zooepidemicus meningitis in a horse trainer and review 36 cases of GCS meningitis reported in the literature. The median age was 48 y and the majority of patients were previously healthy. Thirty-one percent (11/36) of the reported cases followed equine exposure and 19% (7/36) ingestion of dairy products. Sixty-seven percent (24/36) were found to have concomitant bacteraemia. The case fatality rate was 31% (11/36), and 28% (7/25) of survivors were reported to have residual neurological impairments. At least 4 days of antibiotics were typically required before symptoms improved. Isolates were generally susceptible to beta-lactams. In conclusion, it is important to consider GCS in the differential of bacterial meningitis, in particular in elderly patients exposed to horses or dairy products. Beta-lactams are first-line therapy, but outcomes are poor.