Group B streptococcal meningitis in adults: recent increase in Southeast Asia.

Meningitis caused by Streptococcus agalactiae (Group B Streptococcus) is rare in adults and usually affects patients with predisposing conditions. To describe an increase in adult group B streptococcal meningitis occurring in parallel in Hong Kong and Singapore. All cases of bacterial meningitis admitted to the Prince of Wales Hospital, Hong Kong and Singapore General Hospital in 1998, aged 15 years or above, were reviewed. Medical records for the previous ten years were searched for previous cases of adult group B streptococcal meningitis. In 1998, 29 adult patients with bacterial meningitis were admitted to the two hospitals. S. agalactiae was isolated in 11 cases, Streptococcus pneumoniae in three cases, Klebsiella pneumoniae in two cases, and Pseudomonas pseudomallei in one case. In 11 cases no bacteriological diagnosis could be made. Two patients with adult group B streptococcal meningitis had predisposing conditions for infection. One patient died before a definite diagnosis could be established. A ten year review of records revealed one previous case of adult group B streptococcal meningitis in a patient with multiple risk factors. An increase of group B streptococcal meningitis has occurred among adults admitted to two major hospitals in two Southeast Asian cities. In the majority of cases there were no identifiable predisposing conditions. The cause of this increase of group B streptococcal remains unclear.