The impact of non-pharmacological interventions on nasopharyngeal Staphylococcus aureus , streptococcus pneumoniae , moraxella catarrhalis , haemophilus influenzae carriage and the change of pneumococcal vaccination in healthy children under 5 years old in Beijing, China

We analyzed the impact of non-pharmacological interventions (NPIs) andPCV13 inoculation on nasopharyngeal (NP) carriage of Staphylococcus aureus(Sa), Streptococcus pneumoniae (Sp), Moraxella catarrhalis (Mc)and Haemophilus influenzae (Hi) in healthy children under 5 years old inBeijing, China. NP swabs were taken from healthy childrenseeking routine well-child care at the pediatricpreventive health clinic. NP swabs were frozenin Tryptic Soy Broth (TSB) medium and stored at -80°C, and bacterial was detectedby culture. From December 2019 to November 2021, 1939children were enrolled, among whom 278 (14.3%) were found to carry Sa isolates,115 (5.9%) Sp, 39 (2.0%) Mc, and 6 (0.3%) Hi. The carriage of Sa was highest in infants under 6 months, negativelycorrelated with Sp and Mc. The Sa carriage rate in infants below six monthsof age rose from 26.7% in pre-NPIs to 32.7% in post-NPIs early. The13-valent pneumococcal conjugate vaccine (PCV13) uptake rose from 42.3% in December2019 to 62.3% by October 2021. The broad applicationof NPIs caused a decline in Sp and Mc carriage among children under five yearsold, accompanied by an elevation in theSa carriage rate among infants.