The epidemiology of invasive Streptococcus pneumoniae disease in Catalonia (Spain). A hospital-based study.

The aim of this study was to investigate the incidence of invasive pneumococcal disease (IPD) in Catalonia. A hospital-based incidence study of the period 1997-1999 was carried out by reviewing the isolations of Streptococcus pneumoniae obtained from normally sterile sites reported by the hospitals that voluntarily participate in the Microbiological Reporting System of Catalonia (MRSC), and those obtained by active retrospective surveillance of cases recorded by microbiology laboratories of the remaining hospitals. Cases of pneumonia were included only if the blood culture was positive. The age, sex and clinical presentation of each patient were recorded. The global incidence of hospital-based IPD was 10.5 per 100,000 persons-year, and was much higher in subjects <2 years of age (59.6) and in those aged > or = 65 years (27.9). In subjects > or = 65 years, bacteremic pneumococcal pneumonias were more frequent in the months from December to March than they were in children <2 years of age (P<0.0001). The global incidence of IPD (10.5 per 100,000 persons-year) is high in Catalonia, greater than that of meningococcal or Haemophilus influenzae invasive disease. In children <2 years, the incidence is nearly six times higher (59.6 per 100,000 persons-year) with pneumonias (rate of 26.2 per 100,000 persons-year) and non-focal bacteremias (rate of 22.1 per 100,000 persons-year) being especially frequent.