Detection and Density of S. pneumoniae , Cytokine/Chemokine Levels and Mucosal Antibody Levels to Pneumococcus in Nasopharyngeal Samples During SARS-CoV-2 Respiratory Infection in Children.

Background: Streptococcus pneumoniae ( Spn ) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important pathogens. We evaluated the frequency and density of Spn in nasopharyngeal samples, frequency of multiple respiratory virus detection, mucosal cytokine/chemokine levels, and mucosal antibody levels to Spn proteins and capsular polysaccharides during SARS-CoV-2 respiratory infections in children.

Methods: This retrospective study evaluated 222 nasopharyngeal samples collected from children (age 0-18 years) who were tested for SARS-CoV-2 between May 2020 and October 2021. In 111 SARS-CoV-2 positive (+) and 111 SARS-CoV-2 negative (-) samples, we tested for Spn presence and density, 6 viruses (influenza, parainfluenza, respiratory syncytial virus, human rhinovirus, enterovirus and adenoviruses), 9 mucosal cytokine and chemokine levels, mucosal immunoglobulin G (IgG) and IgA antibody levels to Spn PhtD and PcpA proteins and 7 capsular polysaccharides.

Results: Fourteen percent had Spn concurrently present in SARS-CoV-2+ versus 10.6% for SARS-CoV-2-, (not significant). Concurrent SARS-CoV-2 and human rhinovirus detection occurred. Nasopharyngeal cytokine levels in SARS-CoV-2+ samples were not different compared to SARS-CoV-2- samples, except for monocyte chemoattractant protein-1 (higher in SARS-CoV-2+), and not impacted by presence/density of Spn . Nasopharyngeal IgG antibody levels to PhtD and PcpA, and capsular polysaccharide serotypes during SARS-CoV-2+ infections were not different compared to SARS-CoV-2-.

Conclusion: Nasopharyngeal Spn detection and density were not different between SARS-CoV-2+ and SARS-CoV-2- samples in children. Concurrent respiratory virus infection was not common. Nasopharyngeal monocyte chemoattractant protein-1 was higher in SARS-CoV-2+ children. Nasopharyngeal IgG antibody levels to 2 Spn proteins and 7 polysaccharide capsule types did not differ between SARS-CoV-2+ and SARS-CoV-2- samples.