Pneumococcal nasopharyngeal carriage in children and adults self-confined at home during a COVID-19 national lockdown.

Background: Despite growing evidence of reduced invasive and non-invasive pneumococcal disease attributed to public health measures against the COVID-19 pandemic, the effect of these measures on pneumococcal carriage remains unclear. This study aimed to assess pneumococcal nasopharyngeal carriage among children and adults self-confined at home during the COVID-19 national lockdown in Spain while identifying predictors of pneumococcal carriage in children.
Methods: Household study conducted across the metropolitan area of Barcelona (Spain) between April-June 2020. Nasopharyngeal samples were collected from young children and adults for real-time PCR pneumococcal lytA and wgz gene detection, quantification, and serotyping, as well as for detection of respiratory viruses.
Results: Among 332 children (median age: 3.1 years [IQR: 1.9-4.0 years]; 59% male) and 278 adults (median age: 38.9 years [IQR: 36.1-41.3 years]; 64% female), pneumococcal carriage rates were 28.3% and 2.5%, respectively. Highly invasive serotypes 3, 7F/7A, and 19A were detected in 14.0% of samples from children carriers. Pneumococcal co-infections with respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus (IV) were not identified in children. Attendance to kindergarten before the lockdown (aOR: 2.65; IQR: 1.57-4.47; p<0.001) and household crowding (aOR: 1.85; IQR: 1.09-3.15; p = 0.02) were independent risk factors for children's pneumococcal carriage.
Conclusions: Pneumococcal carriage rate among quarantined children during a full COVID-19 lockdown was moderate and correlated with limited presence of highly invasive serotypes and absence of pneumococcal co-infections with RSV, hMPV, and IV. Pre-lockdown daycare and household crowding predisposed children to carriage.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Brotons et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)