Carriage of Streptococcus pneumoniae in adults hospitalised with community-acquired pneumonia

Lansbury, Louise; McKeever, Tricia M.; Lawrence, Hannah; Pick, Harry; Baskaran, Vadsala; Edwards-Pritchard, Rochelle C.; Ashton, Deborah; Rodrigo, Chamira; Daniel, Priya; Litt, David; Eletu, Seyi; Parmar, Hanshi; Sheppard, Carmen L.; Ladhani, Shamez; Trotter, Caroline; Lim, Wei Shen

Abstract

Objectives

We aimed to determine the prevalence of and risk factors for nasopharyngeal and oral pneumococcal carriage in adults with community-acquired pneumonia (CAP), and the relationship between carried and disease-causing serotypes.

Methods

Between 2016 and 2018, nasopharyngeal swabs, oral-fluid, and urine were collected from hospitalised adults recruited into a prospective cohort study of CAP. Pneumococcal carriage was detected by semi-quantitative real-time PCR of direct and culture-enriched nasopharyngeal swabs and culture-enriched oral-fluid. LytA and piaB positive/indeterminate samples underwent semi-quantitative serotype/serogroup-specific real-time-PCR. Serotypes in urine were identified using a 24-valent serotype-specific urinary-antigen assay.

Results

We included 465 CAP patients. Nasopharyngeal carriage was detected in 34/103 (33.0%) swabbed pneumococcal pneumonia patients and oral carriage in 18/155 (12%) of sampled pneumococcal pneumonia patients. Concordance between nasopharyngeal/urine serotypes and oral/urine serotypes was 70.6% and 50% respectively. Serotypes 3 (26%, 22.2%), 8 (19.7%, 19.4%), non-typeable (11.6%, 13.9%) and 19 A/F (7.5%, 8.3%) were most prevalent in urine and nasopharyngeal swabs respectively, with non-typeable (35%) and 15 A/F (17%) most prevalent in oral-fluid. Pneumococcal carriage was significantly associated with pneumococcal pneumonia (nasopharyngeal adjusted odds ratio [aOR] 8.1, 95% confidence interval [CI] 3.8-17.2; oral aOR 5.5, 95% CI 2.1-13.3). All-cause CAP patients ≥65 years had lower odds of nasopharyngeal carriage (aOR 0.47, 95% CI 0.24-0.91) and current smokers had higher odds of oral carriage (aOR 2.69, 95% CI 1.10-6.60).

Conclusions

The association between nasopharyngeal carriage and pneumococcal CAP was strong. Adult carriage and disease from serotypes 8 and 19 A may support direct protection of adults with PCV vaccines.

Citation

Lansbury, L., McKeever, T. M., Lawrence, H., Pick, H., Baskaran, V., Edwards-Pritchard, R. C., Ashton, D., Rodrigo, C., Daniel, P., Litt, D., Eletu, S., Parmar, H., Sheppard, C. L., Ladhani, S., Trotter, C., & Lim, W. S. (2024). Carriage of Streptococcus pneumoniae in adults hospitalised with community-acquired pneumonia. Journal of Infection, 89(5), Article 106277. https://doi.org/10.1016/j.jinf.2024.106277

• Journal Article Type: Article
• Acceptance Date: Sep 13, 2024
• Online Publication Date: Sep 19, 2024
• Publication Date: Nov 1, 2024
• Deposit Date: Sep 23, 2024
• Publicly Available Date: Sep 23, 2024
• Journal: Journal of Infection
• Print ISSN: 0163-4453
• Electronic ISSN: 1532-2742
• Publisher: British Infection Association
• Peer Reviewed: Peer Reviewed
• Volume: 89
• Issue: 5
• Article Number: 106277
• DOI: https://doi.org/10.1016/j.jinf.2024.106277
• Keywords: Serogroup, Carrier state, Pneumonia, Pneumococcal vaccines, Streptococcus pneumoniae
• Public URL: https://nottingham-repository.worktribe.com/output/39731106
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0163445324002111