title: Molecular detection methods and serotyping performed directly on clinical samples improve diagnostic sensitivity and reveal increased incidence of invasive disease by Streptococcus pneumoniae in Italian children.
abstract: The aims of this study were to evaluate the incidence of invasive pneumococcal disease (IPD) in Italian children and perform serotyping by PCR-based assays directly on clinical samples. A 1-year paediatric (0-14 years) population-based surveillance study was designed to evaluate the incidence of IPD in the province of Florence, Italy, by cultural and molecular methods. Among 92 children (80 with pneumonia, 8 with meningitis/sepsis, 4 with arthritis), 4 cases of IPD were diagnosed both by culture and real-time PCR and 18 cases exclusively by molecular methods. The sensitivity of molecular methods was significantly higher than that of cultural methods (Cohen's kappa 0.41; McNemar P=0.000008). The incidence of IPD in children below 2 years of age was 11.5/100,000 and 51.8/100,000 by cultural and molecular methods, respectively. Pneumococcal serotyping by multiplex sequential PCR was obtained in 19/22 samples. Real-time PCR and multiplex sequential PCR can be used directly on biological samples, improving the ability to diagnose IPD. The incidence of IPD appears 5-10 times higher by PCR than by cultural methods.
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Azzari
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Moriondo
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Indolfi
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Massai
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Becciolini
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: de Martino
authors.affiliation: Department of Paediatrics, University of Florence and Anna Meyer Children's Hospital, Viale Pieraccini 24, Florence I-50139, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Resti
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D012703:Serotyping / Q000379:methods*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*