Epidemiology of invasive Streptococcus pneumoniae infections in children in an area of Barcelona, Spain

Abstract

Aim: Streptococcus pneumoniae is the most common cause of bacteraemia, pneumonia, sinusitis and acute otitis media. With the advent of conjugate vaccines, there is now the possibility of preventing disease caused by this organism. However, little is known about the epidemiology of invasive pneumococcal disease in children in Spain. The aim of this study was to determine the incidence and the clinical and microbiologic characteristics of invasive pneumococcal disease in Sabadell, an industrial area in the province of Barcelona, Spain. Methods: From January 1990 to December 2000, the case records of children with pneumococcal invasive disease at Sabadell Hospital were retrospectively (1990–1996) reviewed and prospectively (1997–2000) collected. The hospital serves a population of 61 143 children under 15 y of age, 18 073 children under 4y of age and 7300 children under 2 y of age. Results: A total of 112 children (54% under 24 mo of age and 93% under 6 y of age) with invasive pneumococcal disease were diagnosed during a period of 11 y. The incidence of invasive pneumococcal disease was 76 per 100000 for children aged 0 to 24 mo, 45 for children aged 0–48 mo and 16.6 for children aged 0‐14 y. Occult bacteraemia was the most common manifestation of invasive pneumococcal disease (66 cases), pneumonia was the second form (34 cases) and meningitis (10 cases) and arthritis (2 cases) were the other clinical manifestations. Of the 105 strains tested, 8.6% were highly penicillin resistant, 37.1% were intermediately penicillin resistant, 16.2% were intermediately cefotaxime resistant and 32.4% were erythromycin resistant. Pneumococci of serogroups 6, 14, 18, 19, 1, 5, 4, 9, 23 and 33 were the most frequently isolated groups (92%) but only 6, 9, 14, 19 and 23 were resistant to penicillin, cefotaxime, or erythromycin. Conclusions. In this study the incidence of invasive pneumococcal disease was found to be greater than that reported elsewhere in Spain and Europe. Penicillin resistance levels are high but the trend towards increasing penicillin resistance may have ended over the past few years. The currently licensed seven‐valent (7‐V) pneumococcal conjugate vaccine would cover 78% of cases of invasive pneumococcal in children aged 0–14 y, 80% in children aged 0–24 mo and 100% of cases of penicillin‐ or cefotaxime‐resistant invasive pneumococcal disease.