The impact of private use of PCV7 in 2009 and 2010 on serotypes and antimicrobial resistance of Streptococcus pneumoniae carried by young children in Portugal

Comparison with data obtained since 1996 generating a 15-year study prior to PCV13 introduction

Sónia Nunes, Sofia Félix, Carina Valente, Alexandra S. Simões, Débora A. Tavares, Sónia T. Almeida, Ana C. Paulo, António Brito-Avô, Hermínia de Lencastre, Raquel Sá-Leão

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Abstract

In Portugal, the 7-valent pneumococcal conjugate vaccine (PCV7) was not introduced in the national immunization plan but was commercially available between 2001 and 2010. We studied serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae carried by children in 2009 and 2010. Vaccination with PCV7 was extracted from children's immunization bulletins and information on recent antimicrobial consumption was obtained through a questionnaire. For comparison, we included data from previous studies conducted since 1996: 1996-1999, 2001-2003, 2006-2007. Pneumococci were isolated from nasopharyngeal samples of 1092 children up to six years old attending day-care in an urban area. Among these, 76% (819/1070) were vaccinated and 62% (677/1092) carried pneumococci. In 2009-2010, serotype replacement was extensive. Carriage of PCV7 serotypes was 4.9% and 5.8%, in 2009 and 2010, respectively, with the majority being of serotype 19F (carried by 4.3% and 4.6% of all participants, respectively). Colonization by serotype 19F was associated with vaccine status (7.7% (19/248) of non-vaccinees vs. 3.5% (29/818) of PCV7-vaccinees, p = 0.010). Carriage of serotype 19A was high in 2009 and 2010 (8.6% of all participants) consistent with values already observed in 2007; carriage of serotype 6A was <1% (10/1092), indicating a major decline after 2007 (5.8% or 31/538, p < 0.001). Non-vaccine serotypes increased and serotype 6C became the most frequently carried serotype in 2010 (11.2% (54/481)). High-level resistance to penicillin (MIC ≥2 mg/L) showed a decreasing trend (p < 0.001), whereas resistance to both penicillin and erythromycin increased (p < 0.001) and was detected in 15-20% of all isolates in 2009-2010, most of which were non-vaccine serotypes. Antimicrobial use decreased over time (p < 0.001). In conclusion, widespread private use of PCV7 has impacted on colonization leading to near elimination of all PCV7 serotypes except for serotype 19F. Antimicrobial consumption declined but it may be too soon to observe generalized changes in antimicrobial resistance rates.

Original languageEnglish
Pages (from-to)1648-1656
Number of pages9
JournalVaccine
Volume34
Issue number14
DOIs
Publication statusPublished - 29 Mar 2016

Fingerprint

Streptococcus pneumoniae
Portugal
antibiotic resistance
serotypes
anti-infective agents
penicillins
Serogroup
Immunization
immunization
vaccines
Penicillin Resistance
Conjugate Vaccines
Pneumococcal Vaccines
erythromycin
Erythromycin
Penicillins
urban areas
Vaccination

Keywords

  • Antimicrobial resistance
  • Carriage
  • Children
  • Pneumococcal conjugate vaccine
  • Serotype
  • Streptococcus pneumoniae

Cite this

@article{889bdfe8074f4bb6bbd9fd737b60d005,
title = "The impact of private use of PCV7 in 2009 and 2010 on serotypes and antimicrobial resistance of Streptococcus pneumoniae carried by young children in Portugal: Comparison with data obtained since 1996 generating a 15-year study prior to PCV13 introduction",
abstract = "In Portugal, the 7-valent pneumococcal conjugate vaccine (PCV7) was not introduced in the national immunization plan but was commercially available between 2001 and 2010. We studied serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae carried by children in 2009 and 2010. Vaccination with PCV7 was extracted from children's immunization bulletins and information on recent antimicrobial consumption was obtained through a questionnaire. For comparison, we included data from previous studies conducted since 1996: 1996-1999, 2001-2003, 2006-2007. Pneumococci were isolated from nasopharyngeal samples of 1092 children up to six years old attending day-care in an urban area. Among these, 76{\%} (819/1070) were vaccinated and 62{\%} (677/1092) carried pneumococci. In 2009-2010, serotype replacement was extensive. Carriage of PCV7 serotypes was 4.9{\%} and 5.8{\%}, in 2009 and 2010, respectively, with the majority being of serotype 19F (carried by 4.3{\%} and 4.6{\%} of all participants, respectively). Colonization by serotype 19F was associated with vaccine status (7.7{\%} (19/248) of non-vaccinees vs. 3.5{\%} (29/818) of PCV7-vaccinees, p = 0.010). Carriage of serotype 19A was high in 2009 and 2010 (8.6{\%} of all participants) consistent with values already observed in 2007; carriage of serotype 6A was <1{\%} (10/1092), indicating a major decline after 2007 (5.8{\%} or 31/538, p < 0.001). Non-vaccine serotypes increased and serotype 6C became the most frequently carried serotype in 2010 (11.2{\%} (54/481)). High-level resistance to penicillin (MIC ≥2 mg/L) showed a decreasing trend (p < 0.001), whereas resistance to both penicillin and erythromycin increased (p < 0.001) and was detected in 15-20{\%} of all isolates in 2009-2010, most of which were non-vaccine serotypes. Antimicrobial use decreased over time (p < 0.001). In conclusion, widespread private use of PCV7 has impacted on colonization leading to near elimination of all PCV7 serotypes except for serotype 19F. Antimicrobial consumption declined but it may be too soon to observe generalized changes in antimicrobial resistance rates.",
keywords = "Antimicrobial resistance, Carriage, Children, Pneumococcal conjugate vaccine, Serotype, Streptococcus pneumoniae",
author = "S{\'o}nia Nunes and Sofia F{\'e}lix and Carina Valente and Sim{\~o}es, {Alexandra S.} and Tavares, {D{\'e}bora A.} and Almeida, {S{\'o}nia T.} and Paulo, {Ana C.} and Ant{\'o}nio Brito-Av{\^o} and {de Lencastre}, Herm{\'i}nia and Raquel S{\'a}-Le{\~a}o",
year = "2016",
month = "3",
day = "29",
doi = "10.1016/j.vaccine.2016.02.045",
language = "English",
volume = "34",
pages = "1648--1656",
journal = "Vaccine",
issn = "0264-410X",
publisher = "Elsevier Science B.V., Amsterdam.",
number = "14",

}

TY - JOUR

T1 - The impact of private use of PCV7 in 2009 and 2010 on serotypes and antimicrobial resistance of Streptococcus pneumoniae carried by young children in Portugal

T2 - Comparison with data obtained since 1996 generating a 15-year study prior to PCV13 introduction

AU - Nunes, Sónia

AU - Félix, Sofia

AU - Valente, Carina

AU - Simões, Alexandra S.

AU - Tavares, Débora A.

AU - Almeida, Sónia T.

AU - Paulo, Ana C.

AU - Brito-Avô, António

AU - de Lencastre, Hermínia

AU - Sá-Leão, Raquel

PY - 2016/3/29

Y1 - 2016/3/29

N2 - In Portugal, the 7-valent pneumococcal conjugate vaccine (PCV7) was not introduced in the national immunization plan but was commercially available between 2001 and 2010. We studied serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae carried by children in 2009 and 2010. Vaccination with PCV7 was extracted from children's immunization bulletins and information on recent antimicrobial consumption was obtained through a questionnaire. For comparison, we included data from previous studies conducted since 1996: 1996-1999, 2001-2003, 2006-2007. Pneumococci were isolated from nasopharyngeal samples of 1092 children up to six years old attending day-care in an urban area. Among these, 76% (819/1070) were vaccinated and 62% (677/1092) carried pneumococci. In 2009-2010, serotype replacement was extensive. Carriage of PCV7 serotypes was 4.9% and 5.8%, in 2009 and 2010, respectively, with the majority being of serotype 19F (carried by 4.3% and 4.6% of all participants, respectively). Colonization by serotype 19F was associated with vaccine status (7.7% (19/248) of non-vaccinees vs. 3.5% (29/818) of PCV7-vaccinees, p = 0.010). Carriage of serotype 19A was high in 2009 and 2010 (8.6% of all participants) consistent with values already observed in 2007; carriage of serotype 6A was <1% (10/1092), indicating a major decline after 2007 (5.8% or 31/538, p < 0.001). Non-vaccine serotypes increased and serotype 6C became the most frequently carried serotype in 2010 (11.2% (54/481)). High-level resistance to penicillin (MIC ≥2 mg/L) showed a decreasing trend (p < 0.001), whereas resistance to both penicillin and erythromycin increased (p < 0.001) and was detected in 15-20% of all isolates in 2009-2010, most of which were non-vaccine serotypes. Antimicrobial use decreased over time (p < 0.001). In conclusion, widespread private use of PCV7 has impacted on colonization leading to near elimination of all PCV7 serotypes except for serotype 19F. Antimicrobial consumption declined but it may be too soon to observe generalized changes in antimicrobial resistance rates.

AB - In Portugal, the 7-valent pneumococcal conjugate vaccine (PCV7) was not introduced in the national immunization plan but was commercially available between 2001 and 2010. We studied serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae carried by children in 2009 and 2010. Vaccination with PCV7 was extracted from children's immunization bulletins and information on recent antimicrobial consumption was obtained through a questionnaire. For comparison, we included data from previous studies conducted since 1996: 1996-1999, 2001-2003, 2006-2007. Pneumococci were isolated from nasopharyngeal samples of 1092 children up to six years old attending day-care in an urban area. Among these, 76% (819/1070) were vaccinated and 62% (677/1092) carried pneumococci. In 2009-2010, serotype replacement was extensive. Carriage of PCV7 serotypes was 4.9% and 5.8%, in 2009 and 2010, respectively, with the majority being of serotype 19F (carried by 4.3% and 4.6% of all participants, respectively). Colonization by serotype 19F was associated with vaccine status (7.7% (19/248) of non-vaccinees vs. 3.5% (29/818) of PCV7-vaccinees, p = 0.010). Carriage of serotype 19A was high in 2009 and 2010 (8.6% of all participants) consistent with values already observed in 2007; carriage of serotype 6A was <1% (10/1092), indicating a major decline after 2007 (5.8% or 31/538, p < 0.001). Non-vaccine serotypes increased and serotype 6C became the most frequently carried serotype in 2010 (11.2% (54/481)). High-level resistance to penicillin (MIC ≥2 mg/L) showed a decreasing trend (p < 0.001), whereas resistance to both penicillin and erythromycin increased (p < 0.001) and was detected in 15-20% of all isolates in 2009-2010, most of which were non-vaccine serotypes. Antimicrobial use decreased over time (p < 0.001). In conclusion, widespread private use of PCV7 has impacted on colonization leading to near elimination of all PCV7 serotypes except for serotype 19F. Antimicrobial consumption declined but it may be too soon to observe generalized changes in antimicrobial resistance rates.

KW - Antimicrobial resistance

KW - Carriage

KW - Children

KW - Pneumococcal conjugate vaccine

KW - Serotype

KW - Streptococcus pneumoniae

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U2 - 10.1016/j.vaccine.2016.02.045

DO - 10.1016/j.vaccine.2016.02.045

M3 - Article

VL - 34

SP - 1648

EP - 1656

JO - Vaccine

JF - Vaccine

SN - 0264-410X

IS - 14

ER -