RESUMO
BACKGROUND: Streptococcus pneumoniae and Haemophilus influenzae serotype b (Hib) are two of the most common causes of invasive bacterial disease in children. The introduction of a successful Hib vaccine and the emergence of penicillin-resistant pneumococci have changed the epidemiology of these bacteria over the last few years. OBJECTIVES: To evaluate the incidence of S. pneumoniae and Hib invasive disease in children (0-15 years) admitted to our hospital during a 12-year period (January 1991-December 2002). METHODS: We retrospectively reviewed the medical records of 101 children with isolation of S. pneumoniae and Hib in blood, cerebrospinal fluid (CSF) or synovial fluid samples during the study period. RESULTS: SP was isolated in 81 samples (72 in blood and nine in CSF) from 73 children (72.6 % were aged < 2 years). The annual incidence per 100,000 children aged 0-2 years was 53.76 cases (95 % CI: 40.7-70.9). The most common clinical diagnosis was bacteremia (67 %). The percentage of penicillin-resistant strains was 44 %. Hib was isolated in 38 samples (26 in blood, 10 in CSF and two in synovial fluid) from 28 children (82.1 % were aged < 2 years). The most common clinical diagnosis was meningitis (35.7 %). The annual incidence per 100,000 children aged between 0-5 years dropped from 21.52 cases (95 % CI: 14.4-32) to 1.7 cases (95 % CI: 0.1-10.8) after systematic vaccination. The percentage of ampicillin-resistant strains was 63.1 %. CONCLUSIONS: The incidence of invasive pneumococcal disease and the increased antimicrobial resistance rates of pneumococcus are two major reasons to support the routine use of pneumococcal conjugate vaccination in children. Systematic Hib vaccination since October 1998 has dramatically reduced the incidence of this disease.
