Objective: The purpose of this study was to study the epidemiology of invasive childhood pneumococcal infection in our hospital.
Patients and methods: The records of all children attending our hospital from whom Streptococcus pneumoniae was isolated from the blood or CSF were reviewed. Serotyping and MIC were performed at C.N.M.V.S. (Majadahonda).
Results: Seventy-one pneumococci were isolated in 70 patients. The annual incidence increased from 0.14% to 0.40%. The clinical entities were: bacteremia without focus (45%), pneumonia (29.6%), meningitis (12.7%), cellulitis (5.6%), mastoiditis (5.6%) and endocarditis (1.4%). The age of 72% of the patients was less than 3 years. In 26.8% of the cases, the patient had an underlying disease and/or was previously hospitalized. The antibiotic susceptibility pattern was: penicillin (MIC < or = 0.06 microgram/ml) 45.7%, cefotaxime (MIC < or = 0.5 microgram/ml) 82.8% and erythromycin (MIC < or = 0.5 microgram/ml) 70%. Penicillin resistance of the isolated pneumococci was more often present in the group with risk factors than in those without such risk factors (p < 0.05). There were 13 different serotypes, the most prevalent were 6 (23%), 19 (17%), 14 (14%) and 23 (12%) and the most frequently penicillin-resistant (Resistant N(o)/Total N(o) were: 6 (15/15), 9 (4/4), 14 (8/9) and 23 (6/8).
Conclusions: Streptococcus pneumoniae is a common cause of invasive infections in children in our hospital. There was a high prevalence of serotype 6 (penicillin-resistant) as compared to in adults where serotype 3 (penicillin-susceptible) is the most prevalent. A higher rate of antibiotic resistant strains associated with risk factors (underlying disease or nosocomial acquisition), probably related to prior antibiotic use, was observed.