ABSTRACT
Background: To characterize interferences between Streptococcus pneumoniae and SARS-CoV-2 we investigated the longitudinal patterns of viral infection and pneumococcal carriage in households infected with SARS-CoV-2. Methods: SARS-CoV-2 and pneumococcus were detected with quantitative molecular methods in saliva from members of eighty participating households. Samples were collected between October 2020 and January 2021 from n=197 adults and n=118 children of which n=176 adults and n=98 children had a complete set of ten samples collected within 42 days since enrolment. Time-dependent Cox models were used to evaluate the associations between SARS-CoV-2 and pneumococcal carriage. Results: In the entire cohort, cumulative pneumococcal carriage and SARS-CoV-2 infection rates were 58% and 65%, respectively. Pneumococcal abundances were associated with an increased risk of SARS-CoV-2 infection (HR 1.14, 95% CI, 1.01-1.29, P=0.04) and delayed clearance of SARS-CoV-2 infection (HR 0.90, 95% CI, 0.82-0.99, P=0.03). Elevated viral loads were observed among pneumococcal carriers and individuals with high overall bacterial 16S abundances, however, there were no longitudinal differences in viral loads in linear mixed-effects models. Individuals with high 16S abundances displayed delayed viral clearance (HR 0.65, 95% CI 0.55-0.78, P<0.0001). Conclusions: Although we found insufficient evidence for a strong impact of SARS-CoV-2 infection on pneumococcal carriage. Results from the current study suggest that pneumococcal carriers may have an increased risk of SARS-CoV-2 infection and high pneumococcal abundances and 16S abundances may be associated with elevated viral loads and delayed clearance of SARS-CoV-2 infection.