[Study of the incidence of invasive pneumococcal disease in neonates and childre aged less than 5 years in the Basque country and Navarre (Spain)].

Abstract

Background: Streptococcus pneumoniae is the most commonly reported bacterial cause of bacteremia and bacteremic pneumonia and the second most frequent cause of meningitis.

Objective: To establish the incidence, characteristics and serotypes causing invasive pneumococcal disease in children aged less than 5 years in two Autonomous Communities in Spain, the Basque country and Navarre, between 31 May 1988 and 1 June 2001.

Patients and methods: We performed a descriptive, observational and retrospective study. The study population was composed of children diagnosed with invasive pneumococcal disease in the public and private hospitals with a pediatrics departments. Invasive pneumococcal disease was defined as isolation of S. pneumoniae in blood, cerebrospinal fluid or any other sterile biological fluid. Medical records were reviewed and demographic and diagnostic variables were analyzed. Age-adjusted frequency rates were established for both regions using direct standardization. Confidence intervals were obtained by Poisson distribution. SPSS for Windows 10.0 and Epidat 2.1 were used for the analysis. Data were obtained from the 1999 municipal population census.

Results: One hundred seventy-one children aged 0-5 years were included. A total of 40.9 % (70 patients) were aged less than 12 months and 68.4 % were aged 0-2 years; 16.4 % had received drug therapy before diagnosis. The most common forms of presentation were occult bacteremia (45.6 %), bacteremic pneumonia (27.5 %) and meningitis (14.6 %). The most frequent complications involved the respiratory tract, with pleural effusion in 23 % of cases of pneumonia. The standardized annual incidence rate of invasive pneumococcal disease (cases per 100,000) in children aged 0-59 months was 58.82 (95 % CI: 27.99-89.65) in Navarre and 55.35 (95 % CI: 38.81-71.88) in the Basque Country. In children aged 0-23 months, the overall incidence was 93.49 cases per 100,000 children (95 % CI: 77.32-112.04) and in infants aged 0-11 months, it was 110,21 cases per 100,000 children (95 % CI: 85.91-139.24). The incidence rates for meningitis and bacteremia in children aged 0-23 months was 15.98 (95 % CI: 9.76-24.68) and 51.14 (95 % IC: 39.38-65.30) cases per 100.000 children. Fifty-nine strains were serotyped. The most frequent serotypes/groups were 1, 4, 6B, 14, 18C, 19 and 23F. A total of 52.15 % of the serotypes were penicillin-susceptible and 93 % were cefotaxime-susceptible. The serotypes/groups with the highest rates of resistance were 6B, 14,19, 23F and 35.

Conclusion: Our incidence rates are similar to those observed in other countries such as the United States and are higher than those reported for the rest of Europe. Vaccine coverage is similar to that described in other articles.