Oropharyngeal and nasal Staphylococcus aureus carriage by healthy children.

Claudio Pelucchi,Walter Peves Rios,Nicola Principi,Alberto Zampiero,Susanna Esposito,Leonardo Terranova,Valentina Ierardi

doi:10.1186/s12879-014-0723-9

Abstract

BackgroundAs healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community, it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of Staphylococcus aureus circulation. The aim of this study was to evaluate oropharyngeal and nasal S. aureus carriage in otherwise healthy children and adolescents aged 6–17 years.MethodsThe oropharyngeal and nasal samples were collected in December 2013 from 497 healthy students attending five randomly selected schools in Milan, Italy, using an ESwab kit, and S. aureus was identified using the RIDA®GENE methicillin-resistant S. aureus (MRSA) system.ResultsTwo hundred and sixty-four subjects (53.1%) were identified as S. aureus carriers: 129 (25.9%) oropharyngeal carriers and 195 (39.2%) nasal carriers, of whom 60 (12.1%) were both oropharyngeal and nasal carriers. Oropharyngeal carriage increased with age (p < 0.001), whereas nasal carriage decreased. There was little or no agreement between oropharyngeal and nasal carriage in any of the age groups. MRSA was identified in only three cases (0.6%), always in nasal samples. There were no differences between the carriers and non-carriers in terms of the distribution of age, gender, ethnicity, the number of siblings in the household, exposure to passive smoking, previous clinical history, allergic sensitisation, or previous influenza, pneumococcal and meningococcal vaccinations. The frequency of male children was higher among the subjects with positive nasal and oropharyngeal swabs (66.7%) than among those with positive oropharyngeal swabs alone (46.4%; p = 0.02).ConclusionsThe oropharyngeal carriage of mainly methicillin-sensitive S. aureus is frequent in otherwise healthy children, including a relatively high proportion of those without nasal colonisation. These findings highlight the importance of adding throat to nasal screening when monitoring the circulation of S. aureus in the community.

Highlights

IntroductionAs healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community, it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of Staphylococcus aureus circulation
As healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community [1], it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of S. aureus circulation
Of the 497 remaining children, 264 (53.1%) were identified as S. aureus carriers: 129 (25.9%) oropharyngeal carriers and 195 (39.2%) nasal carriers, of whom 60 (12.1%) were both oropharyngeal and nasal carriers. This indicates that the use of oropharyngeal swabs increased the identification of S. aureus carriage by about 13.8%

Summary

Introduction

As healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community, it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of Staphylococcus aureus circulation. Additional screening is currently considered unnecessary [1], Esposito et al BMC Infectious Diseases (2014) 14:723 but the findings of recent studies indicate that the throat can be an important site of S. aureus colonisation, and that a relatively large number of subjects may be colonised exclusively in the throat [7,8,9,10,11], and would be missed by nasal screening This has led some authors to conclude that S. aureus screening should include both nose and throat swabs in order to allow a complete evaluation [12]. As healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community [1], it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of S. aureus circulation

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