title: Carriage of Streptoccoccus pneumoniae in healthy adults aged 60 years or over in a population with very high and long-lasting pneumococcal conjugate vaccine coverage in children: rationale and perspectives for PCV13 implementation.
abstract: A serial cross-sectional study of nasopharyngeal carriage among adults aged 60 y or over was conducted in winter-spring 2012 with the aim to describe circulating Streptococcus pneumoniae in an area, Liguria Administrative Region, where the vaccine was implemented for a decade and coverage in pediatric age group reached a value close to 100% for more than 5 y, determining a picture of very high vaccine immunological pressure. The serotype-specific carriage picture in adults was compared with that observed in children by means of a cross-sectional study performed one year before using the same sampling and laboratory methods.   Cluster sampling enrolled 283 adults, representative of the open population. Detection of multi-serotype carriage was performed using, real-time PCR and primer specific PCRs. Carriage prevalence of participants with at least one positive sample adjusted for age, i.e., period prevalence, was 18.7%, considering the Ligurian population as standard population, showing that the pneumococcal carriage in the elderly is not a rare event as emerged in other surveys. The long-term use of PCV7 has resulted in strong decrease of vaccine types carriage among adults and children. A multivariate analysis showed that age class and contact with children attending day care covariates were strongly associated with Streptococcus pneumoniae carriage. A strong link between the picture observed in < 5-y-old children and ≥ 60-y-old adults emerged: a strong correlation of specific-serotype prevalence between adults and children and risk factor analysis supported the role played by inter-age-group transmission.
authors.affiliation: I.R.C.C.S. "A.O.U. San Martino-IST"; Genoa, Italy; Department of Health Sciences; University of Genoa; Genoa, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Ansaldi
authors.forename: Daniela
authors.initials: D
authors.lastname: de Florentiis
authors.forename: Paola
authors.initials: P
authors.lastname: Canepa
authors.forename: Antonella
authors.initials: A
authors.lastname: Ceravolo
authors.forename: Emanuela
authors.initials: E
authors.lastname: Rappazzo
authors.forename: Rocco
authors.initials: R
authors.lastname: Iudici
authors.forename: Mariano
authors.initials: M
authors.lastname: Martini
authors.forename: Gerardo
authors.initials: G
authors.lastname: Botti
authors.forename: Andrea
authors.initials: A
authors.lastname: Orsi
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Icardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Durando
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000302:isolation & purification*
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines
keywords: S. pneumoniae; carriage; conjugate vaccine; replacement; vaccine prevention