Invasive pneumococcal disease (IPD), which is defined as an infectious disease caused by Streptococcus pneumoniae in blood or cerebral spinal fluid, is the target of notifiable disease surveillance for Category V infectious disease in the Infectious Disease Control Law. Recently the incidence of IPD has decreased reciprocally since the vaccine for S. pneumoniae was developed. The infection by non-vaccine serotype (nVT) S. pneumoniae has, however become a new threat in Japan.
A-75-year-old male was admitted our hospital with a fever. Physical examination showed disturbance of consciousness and neck stiffness. A spinal tap showed an increase in the white blood cell count in his cerebrospinal fluid (CSF) and positivity for the S. pneumoniae antigen. S. pneumoniae was detected in both blood and CSF cultures. MRI findings showed an abscess in the left frontal lobe of the brain. Based on these findings, the diagnosis of IPD was made. Further studies revealed his serotype of S. pneumoniae was 7C. He had received 23-valent pneumococcal polysaccharide vaccine (PPSV23) once before this episode. Serotype 7C was not included in PPSV23. At the same time, untreated diabetes mellitus was found and insulin therapy was started immediately. He was treated successfully with the administration of several antibiotics and the surgical resection of the brain abscess. The nVT S. pneumoniae is an emerging pathogen and has the capability to cause IPD.
