Resumen

RUVINSKY, Raúl et al. Invasive streptoccocus pneumoniae. Rev. bol. ped. [online]. 2004, vol.43, n.2, pp.107-115. ISSN 1024-0675.

Since 1993, the PAHO, through the Regional Vaccine System (SIREVA Group) organized a surveillance protocol of invasive Streptococcus pneumoniae (Spn) infections in children less than 5 years old in six Latin-American countries: Argentina, Brazil, Chile, Colombia, Mexico and Uruguay. In Argentina more than 20 hospitals are now participating in this project. Objectives: 1) to determine the predominant serotypes, the antibiotic resistance and changes along the time. 2) To know the representativity of the serotypes isolated in the new conjugated vaccines. Methodology: children less than 6 years old hospitalized by Spn invasive infections were included (pneumonia, meningitis, bacteremia o sepsis). The ANLISS "Dr. Carlos G. Malbrán" Institute was the reference center for Spn serotyping and antibiotic resistance determination. Results: Spn was isolated from 1.390 clinical samples. The average age was 19.5 months, 74.4% belonged to children equal or less than 2 years of age. The main clinical diagnosis were: pneumonia 60.5%, meningitits 26.6%, fever without foccus (bacteremia) or sepsis 8.2%. Decreased penicillin sensitivity (DPS) was found in 32.1% of the cases, with high resistance in 16.1% and intermediate resistance in 16%; the increase of DPS in the 1993- 98 period was significant, like in other countries. The more frequent serotypes were: 14 (32.5%), 6A/6B, 9V, 23F, 19F, 18C, 4, 5, and 1. Serotypes 14 and 6AB were prevalent in children less than 2 years old and serotypes 5 and 1, in children than 2 years older (p <0.001). Serotype 14, pneumonia and age less than 2 years were risk factors for penicillin resistance. Finally, the representativity of the serotypes in the new conjugated vaccines 7- valent, 9-valent and 11-valent was: 53.3%, 77.4% and 82.6% respectively. For the 7-valent vaccine, was higher in the less than 2 years old group (61.2%), and for this age group with pneumonia (71.2%). More than 90% of penicillin resistant serotypes were included in the three conjugated vaccines. Conclusions: a national surveillance program was developped in Argentina and other Latin-American countries. Prevalent invasive Spn serotypes were identified; a significative increase in penicillin and other antibiotic resistance was found, like in almost all countries. This epidemiologic information is of great importance for evaluating the new conjugated vaccines.

Palabras clave : Streptococcus; pneumoniae; pneumococcal infections; epidemiology.