Relationship between serotypes, age, and clinical presentation of invasive pneumococcal disease in Madrid, Spain, after introduction of the 7-valent pneumococcal conjugate vaccine into the vaccination calendar.
To assess invasive pneumococcal disease (IPD) clinical presentations and relationships with age and serotype in hospitalized children (<15 years) after PCV7 implementation in Madrid, Spain, a prospective 2-year (May 2007 to April 2009) laboratory-confirmed (culture and/or PCR) IPD surveillance study was performed (22 hospitals). All isolates (for serotyping) and culture-negative pleural/cerebrospinal fluids were sent to the reference laboratory for pneumolysin (ply) and autolysin (lyt) gene PCR analysis. A total of 330 IPDs were identified: 263 (79.7%) confirmed by culture and 67 (20.3%) confirmed by PCR. IPD distribution by age (months) was as follows: 23.6% (<12), 15.8% (12 to 23), 15.5% (24 to 35), 22.4% (36 to 59), and 22.7% (>59). Distribution by clinical presentation was as follows: 34.5% bacteremic pneumonia, 30.3% pediatric parapneumonic empyema (PPE), 13.6% meningitis, 13.3% primary bacteremia, and 8.2% others. Meningitis and primary bacteremia were the most frequent IPDs in children <12 months old, and bacteremic pneumonia and PPE were most frequent in those >36 months old. Frequencies of IPD-associated serotypes were as follows: 1, 26.1%; 19A, 18.8%; 5, 15.5%; 7F, 8.5%; 3, 3.9%; nontypeable/other 30 serotypes, 27.3%. Serotype 1 was linked to respiratory-associated IPD (38.6% in bacteremic pneumonia and 38.0% in PPE) and children of >36 months (51.4% for 36 to 59 months and 40.0% for >59 months), while serotype 19A was linked to nonrespiratory IPDs (31.1% in meningitis, 27.3% in primary bacteremia, and 51.9% in others) and children of <24 months (35.9% for children of <12 months and 36.5% for those 12 to 23 months old), with high nonsusceptibility rates for penicillin, cefotaxime, and erythromycin. After PCV7 implementation, non-PCV7 serotypes caused 95.5% of IPDs. The new 13-valent conjugate vaccine would provide 79.1% coverage of serotypes responsible for IPDs in this series.
Microbiology Department, Hospital Clínico San Carlos, c/ Martín Lagos s/n, 28040 Madrid, Spain. jpicazo@microb.net
J
J
Picazo
J
J
Ruiz-Contreras
J
J
Casado-Flores
E
E
Giangaspro
F
F
Del Castillo
T
T
Hernández-Sampelayo
E
E
Otheo
F
F
Balboa
E
E
Ríos
C
C
Méndez
D017677:Age Distribution; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003470:Culture Media; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000235:genetics; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D016133:Polymerase Chain Reaction; D011159:Population Surveillance / Q000379:methods; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D013301:Streptolysins / Q000235:genetics; D014611:Vaccination
D001426:Bacterial Proteins; D003470:Culture Media; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae; D009238:N-Acetylmuramoyl-L-alanine Amidase