[A rare case of Streptococcus agalactiae meningitis in previously healthy adult].

A 39-year-old previously healthy man was referred to our hospital because of acute onset of fever and consciousness disturbance. Neurological examinations revealed deteriorated consciousness, nuchal rigidity and Kernig's sign. A lumbar puncture yielded clouded fluid with a WBC 1,012/μl (polynuclear cell 96%), 147.3 mg/dl of protein, 44 mg/dl of glucose and Gram positive cocci. At first, he was treated with ceftriaxon and ampicillin. At Day 2, meropenem was added. Streptococcus agalactiae was isolated from blood and cerebrospinal fluid. He responded promptly to antimicrobial therapy, and within 2 days, he became lucid and afebrile. S. agalactiae was sensitive to ceftriaxone, ampicillin and meropenem. After Day 3, he was treated with meropenem only. We diagnosed his condition as S. agalactiae meningitis and was discharged from our hospital at Day 18. Many cases of S. agalactiae meningitis are known to occur in neonates, pregnant women, elderly, and persons with underlying disease such as diabetes, malignant disorders, liver dysfunction. But cases occurring in a previously healthy adult are rare. Neurologists should be aware that S. agalactiae may be cause bacterial meningitis in a previously healthy adults.