Prospective hospital based multicenter adult pneumonia surveillance in Japan, the most aged population; a mid-term progress report of APSG-Japan

Background : Pneumonia is the 3rd leading cause of death in Japan. Beside community-acquired pneumonia (CAP), health care associated pneumonia (HCAP) is also important in the elderly. It is vital to investigate the incidence of CAP/HACP and the extent to which vaccine preventable pathogens were involved for making rational public health policy. However epidemiology of pneumonia is largely unknown in Japan. Objectives : 1) to estimate CAP and HCAP incidence; 2) to describe aetiologic pathogens and serotype distribution of S pneumoniae in Japan. Methods : A prospective multicenter study is being conducted targeting adult patients diagnosed as either CAP or HCAP at four community-based hospitals (total 1805 beds) since Sep 2011. Clinical data and sputum samples were collected and tested by culture and in-house multiplex PCR detecting 12 viruses and 6 bacteria. S. pneumoniae positive samples were examined for serotypes. Results : The mean duration of survey was 8.4 months; the total number of actively enrolled cases was 960 (CAP; 72%), which accounts for 70-80% of total pneumonia cases registered in the each hospital data base. 58% were male and the median age was 77 (15-103) years. S. pneumoniae (13.2%) and H infulenzae (14.7%) were leading causative pathogens by culture; multiplex PCR revealed a higher prevalence (19.3%) of S. pneumoniae, of which 52.6% were compatible with PCV 13 vaccine serotypes. Respiratory virus was frequently detected (28%). Conclusion : The APSG-Japan has successfully launched and the information of CAP/HCAP is accumulating. The whole picture of pneumonia epidemiology with overall incidence in Japan will be soon clarified.