Invasive Streptococcus pneumoniae Infection in Latin American Children: Results of the Pan American Health Organization Surveillance Study

Abstract

Protein-polysaccharide conjugate vaccines against Streptococcus pneumoniae promise to be an effective public health intervention for children, especially in an era of increasing antimicrobial resistance. To characterize the distribution of capsular types in Latin America, surveillance for invasive pneumococcal infection in children < or = 5 years of age was done in six countries between February 1993 and April 1996. Fifty percent of 1,649 sterile-site isolates were from children with pneumonia, and 52% were isolated from blood. The 15 most common of the capsular types prevalent throughout the region accounted for 87.7% of all isolates. Overall, 24.9% of isolates had diminished susceptibility to penicillin: 16.7% had intermediate resistance and 8.3% had high-level resistance. Three customized vaccine formulas containing 7, 12, and 15 capsular types were found to have regional coverages of 72%, 85%, and 88%, respectively. This study emphasizes the need for local surveillance for invasive pneumococcal disease prior to the development and evaluation of protein-polysaccharide conjugate vaccines for children.

Meeting the challenge: prevention of pneumococcal disease with conjugate vaccines

“…The study reported that overall, 24.9% of isolates had diminished susceptibility to penicillin; 16.7% had intermediate resistance, and 8.3% had high-level resistance. 12 The same group had recently reported an overall resistance to penicillin of 34.2%; the lowest resistance to penicillin was reported in Brazil (22.3%) and the highest in Mexico (49.4%) among pediatric invasive pneumococcal isolates. 19 The first multiple resistant strains of pneumococci were found in children; since then, resistant strains have been shown to be more common in children than in adults.…”

“…Children of this age group are more likely to be infected by pneumococci and have a decreased susceptibility to penicillin than older children. [12][13][14][15][16][17][18][19] Considering the development of multivalent pneumococcal conjugate vaccines and the results of the first large clinical trial of a pneumococcal 7-valent conjugate vaccine (PNCRM7; Prevenar ® /Prevnar ® ), the objectives of this article are to: a) review the characteristics and methods of transmission/carriage of S. pneumoniae; b) review the clinical epidemiology of pneumococcal diseases (both invasive and noninvasive); c) describe the rationale for vaccination against this pathogenic organism; and d) review the efficacy of the pneumococcal conjugate vaccines currently under investigation or commercially available.…”

“…Independent of race, children younger than two years experience a 10-fold increased incidence of bacteremia compared with matched adult populations. 8,12,67 Bacterial pneumonia most commonly occurs in the very young and the elderly; the spectrum of disease varies from mild to life threatening. Complications may include empyema, a self-limited pleural effusion, or extra pulmonary manifestations (e.g., bacteremia, meningitis).…”

“…However, a recent retrospective study has shown that vaccination with 23PS reduces rates of hospitalization for pneumonia and for all-cause mortality in persons with chronic lung disease. 12,86 Although the benefits of 23PS are undeniable, it has several limitations. 87 Several case-control studies and serotype prevalence evaluations have suggested an overall efficacy for 23PS of 50% to 81% for vaccinespecific serotypes in adults with bacteremic disease.…”

Evaluación pre-analítica de dos métodos de extracción de ADN para la amplificación del gen de la pneumolisina (PLY) de Streptococcus pneumoniae, en muestras de hemocultivo

“…El diagnóstico etiológico en estas infecciones, especialmente en niños, se ve dificultado debido a la obtención de muestras poco representativas del foco infeccioso 3 . La muestra más accesible es la expectoración, pero obtener una expectoración de buena calidad es difícil y su sensibilidad es bastante reducida, en tanto el hemocultivo posee un bajo rendimiento diagnóstico con técnicas tradicionales.…”