Streptococcus equi subsp. equi meningitis, septicemia and subdural empyema in a child

Streptococcus equi subsp. equi is a group C β-hemolytic streptococcus, and is an invasive pathogen with a very restricted host, causing the equine infection known as ‘strangles’. It is a poor colonizer in horses, preferentially causing invasion and infection, compared with its ancestor Streptococcus equi subsp. zooepidemicus, which is considered an opportunistic commensal of the equine upper respiratory tract. In humans, S. equi subsp. equi causes invasive infections in immunocompromised hosts, often following close contact with horses. Such infections are associated with a high mortality, as well as a poor neurological outcome in survivors. Beta-lactam antimicrobials form the mainstay of treatment, while neurosurgical intervention is occasionally required. We present the case of a 13-year old boy with systemic lupus erythematosus being treated with hydroxychloroquine, who presented with S. equi subsp. equi meningitis and sepsis after contact with a sick pony. Although he recovered fully following eight weeks of intravenous ceftriaxone and oral rifampin, the clinical course was complicated by subdural empyema requiring neurosurgical evacuation.