Decreased Pneumococcal Carriage Among Older Adults in Denmark During the COVID-19 Lockdown

Michaela Tinggaard; Hans-Christian Slotved; Randi Føns Petersen; Nichlas Hovmand; Thomas Benfield

doi:10.1093/ofid/ofad365

Decreased Pneumococcal Carriage Among Older Adults in Denmark During the COVID-19 Lockdown

Open Forum Infect Dis. 2023 Jul 20;10(8):ofad365. doi: 10.1093/ofid/ofad365. eCollection 2023 Aug.

Authors

Michaela Tinggaard¹, Hans-Christian Slotved², Randi Føns Petersen², Nichlas Hovmand¹, Thomas Benfield^{1

3}

Affiliations

¹ Department of Infectious Diseases, Copenhagen University Hospital-Amager and Hvidovre, Hvidovre, Denmark.
² Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark.
³ Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.

Abstract

Background: COVID-19 containment measures reduced the burden of invasive pneumococcal disease. Data on pneumococcal carriage rates among adults during the pandemic are scarce.

Methods: Naso- and oropharyngeal swabs and questionnaires were collected during January 2019 to December 2021 from adults ≥64 years of age. Carriage was determined by lytA/piaB PCR.

Results: A total of 1556 participants provided paired naso- and oropharyngeal swabs. Their median age was 74 years (IQR, 70-79). Streptococcus pneumoniae DNA was detected in 146 (9.4%) oropharyngeal swabs and 34 (2.2%) nasopharyngeal. The carriage rate decreased from 12.9% (95% CI, 10.1%-16.1%, n = 66/511) prelockdown (January 2019-February 2020) to 4.2% (95% CI, 2.0%-7.5%, n = 10/240) during lockdown (March 2020-February 2021) and increased to 12.1% (95% CI, 9.8%-14.7%, n = 87/719) with the reopening of society (March 2021-December 2021; P = .0009).

Conclusions: Pneumococcal carriage prevalence declined significantly during pandemic mitigation measures and rebounded to prepandemic levels as measures were lifted.

Keywords: COVID-19 pandemic; adults; carriage; pneumococcus; surveillance.