title: Epidemiology of Streptococcus pneumoniae causing acute otitis media among children in Southern Catalonia throughout 2007-2013: Incidence, serotype distribution and vaccine's effectiveness.
abstract: OBJECTIVE
  This study investigated incidence and serotype distribution of Streptococcus pneumoniae causing acute otitis media (AOM) in Catalonian children, evaluating vaccination effectiveness in the current era of extended valency pneumococcal conjugate vaccines (PCVs).
  
  
  METHODS
  Population-based surveillance study that included all AOM cases with isolation of pneumococcus (from otic fluids/otorrea) identified among children ≤14 years in the region of Tarragona (Southern Catalonia, Spain) from 01/01/2007 to 31/12/2013. Prevalence of infections caused by serotypes covered by the different PCVs formulations were calculated for the periods before and after 30/06/2010 (date of PCV7/PCV13 replacement). The indirect cohort method was used to estimate PCV7/13 effectiveness against vaccine-type infections.
  
  
  RESULTS
  A total of 78 children with a pneumococcal AOM were identified across study period, which meant an incidence rate of 23 cases per 100,000 population-year. Thirty-six cases (46.2%) occurred within the late PCV7 era and 42 cases (53.8%) during the early PCV13 era. Overall, the most common serotypes were type 19A (21.7%), type 3 (13.3%) and type 15B (6.7%). Prevalence of cases caused by serotypes included in PCV7 did not substantially change between the first and the second study period (from 10.3% to 12.9%), whereas prevalence of cases caused by PCV13 serotypes showed a decreasing trend between both periods (from 65.5% to 48.4%). The aggregate PCV7/13 effectiveness against vaccine-type infections was 72% (95% confidence interval: -26 to 94).
  
  
  CONCLUSIONS
  Pneumococcal conjugate vaccination appears an acceptable preventive option to prevent pneumococcal AOM in infants. However, its serotype coverage and clinical effectiveness are not optimal.
authors.affiliation: Primary Care Service of Camp de Tarragona, Institut Catala de la Salut, Rambla Nova 124, D, 1°A, 43001 Tarragona, Spain. Electronic address: oochoa.tarte.ics@gencat.cat.
authors.forename: O
authors.initials: O
authors.lastname: Ochoa-Gondar
authors.affiliation: Department of Otorhinolaryngology, Joan XXIII Hospital, Dr. Mallafrè Guasch, 4, 43005 Tarragona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Figuerola-Massana
authors.affiliation: Primary Care Service of Camp de Tarragona, Institut Catala de la Salut, Rambla Nova 124, D, 1°A, 43001 Tarragona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Vila-Corcoles
authors.affiliation: Primary Care Service of Camp de Tarragona, Institut Catala de la Salut, Rambla Nova 124, D, 1°A, 43001 Tarragona, Spain.
authors.forename: C A
authors.initials: CA
authors.lastname: Aguirre
authors.affiliation: Primary Care Service of Camp de Tarragona, Institut Catala de la Salut, Rambla Nova 124, D, 1°A, 43001 Tarragona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: de Diego
authors.affiliation: Primary Care Service of Camp de Tarragona, Institut Catala de la Salut, Rambla Nova 124, D, 1°A, 43001 Tarragona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Satue
authors.affiliation: Department of Laboratory and Microbiology, Joan XXIII Hospital, Dr. Mallafrè Guasch, 4, 43005 Tarragona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Gomez
authors.affiliation: Department of Laboratory and Microbiology, Santa Tecla Hospital, Rambla Vella, 14, 43003 Tarragona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Raga
mesh_terms: D000208:Acute Disease; D002648:Child; D002675:Child, Preschool; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D010033:Otitis Media / Q000382:microbiology* / Q000517:prevention & control; D011008:Pneumococcal Infections / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control*; D011159:Population Surveillance; D015995:Prevalence; D065288:Serogroup; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000276:immunology*; D014611:Vaccination; D018074:Vaccines, Conjugate
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D018074:Vaccines, Conjugate
keywords: Acute otitis media; Children; Effectiveness; Pneumococcal conjugate vaccine; Serotype; Streptococcus pneumoniae