Asymptomatic carriage of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Group A Streptococcus and Staphylococcus aureus among adults aged 65 years and older

PLoS One. 2019 Feb 8;14(2):e0212052. doi: 10.1371/journal.pone.0212052. eCollection 2019.


Objective: The aim of this study was to determine the prevalence of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, group A Streptococcus (GAS), and Staphylococcus aureus in asymptomatic elderly people and to unravel risk factors leading to colonization.

Methods: A multi-centre cross-sectional study was conducted including 677 asymptomatic adults aged 65 years or more, living at home or in nursing homes. Study areas were Greater Aachen (North-Rhine-Westphalia) and Wuerzburg (Bavaria), both regions with medium to high population density. Nasal and oropharyngeal swabs as well as questionnaires were collected from October 2012 to May 2013. Statistical analysis included multiple logistic regression models.

Results: The carriage rate was 1.9% ([95%CI: 1.0-3.3%]; 13/677) for H. influenzae, 0.3% ([95%CI: 0-1.1%]; 2/677) for N. meningitidis and 0% ([95% CI: 0-0.5%]; 0/677) for S. pneumoniae and GAS. Staphylococcus aureus was harboured by 28.5% of the individuals ([95% CI: 25.1-32.1%]; 193/677) and 0.7% ([95% CI: 0.2-1.7%]; 5/677) were positive for methicillin-resistant S. aureus. Among elderly community-dwellers colonization with S. aureus was significantly associated with higher educational level (adjusted OR: 1.905 [95% CI: 1.248-2.908]; p = 0.003). Among nursing home residents colonization was associated with being married (adjusted OR: 3.367 [1.502-7.546]; p = 0.003).

Conclusion: The prevalence of N. meningitidis, H. influenzae, S. pneumoniae and GAS was low among older people in Germany. The S. aureus rate was expectedly high, while MRSA was found in less than 1% of the individuals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carrier State
  • Cross-Sectional Studies
  • Female
  • Haemophilus Infections / epidemiology*
  • Humans
  • Logistic Models
  • Male
  • Meningitis, Meningococcal / epidemiology*
  • Nasopharynx / microbiology
  • Nursing Homes
  • Pneumococcal Infections / epidemiology*
  • Staphylococcal Infections / epidemiology*
  • Streptococcal Infections / epidemiology

Grants and funding

The study was supported by the German Federal Ministry of Health via the Robert Koch Institute and its National Reference Laboratories Network (FKZ 415). This publication was funded by the German Research Foundation (DFG) and the University of Wuerzburg in the funding programme Open Access Publishing. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.