The Carrier Status of Streptococcus pneumoniae in a Multi-National Medical Student Population

Nasopharyngeal carriage of Streptococcus pneumoniae (S. pneumoniae) is a well-established risk factor for invasive disease. An unnecessarily high incidence of morbidity attributed to S. pneumoniae is vaccine-preventable. The objectives of this study were to determine the prevalence of S. pneumoniae carriage and to analyze the different vaccination schemes in a multinational population of final-year medical students.

An observational cross-sectional study including final-year medical students attending their Infectious Diseases rotation.

One nasal and pharyngeal swab were collected from each participant who underwent a minimum eight-hour period of fasting and without rinsing or brushing teeth. Written informed consent was obtained from all participants. A univariate statistical analysis was carried out with statistical significance set at p <0.05.

Fifty students agreed to participate in this study (age range: 23-35, average: 24.86 ± 2.12 years). Six (12%) students had the pneumococcal vaccine: four (16%) from the foreign group and two (8%) from the Romanian group (OR: 2.19, 95% CI: 0.36-13.21, p=0.39). The carrier status for S. pneumoniae was 0%. A total of 12 (24%) specimens yielded microbial presence: S. aureus (n=8), S. pyogenes (n=1), Group C Streptococcus (n=1), Group G Streptococcus (n=1) and K. pneumoniae (n=1). All 13 (26%) specimens of alpha-hemolysis were identified from foreign students (OR: 55.08, 95% CI: 3.02-1003.75, p=0.0068), but had no clinical relevance, S. pneumoniae being ruled out.

The carrier status among vaccinated participants was 0%. The rate of microorganism isolation was twice that in Romanian students compared to foreign students.