1141. Effect of the SARS-CoV-2 Pandemic on Staphylococcus aureus Colonization in Healthy Children
Authors: McNeil Jonathon C , Joseph Marritta , Sommer Lauren , Flores Anthony R , Flores Anthony R 
Published: December 2021

Abstract

Background
Staphylococcus aureus is a common colonizer of the skin and mucus membranes. Several investigators have reported reductions in a number of childhood infections temporally associated with social distancing/masking mandates intended to curb the SARS-CoV-2 pandemic. No data are available regarding the impact of these measures on bacterial colonization. We report preliminary results from an ongoing longitudinal S. aureus colonization study initiated just prior to the pandemic.

Methods
Healthy children &lt; 18 years were recruited from 2 Houston-area primary care clinics from Nov 2019- Feb 2020. Subjects had anterior nares and axillary cultures obtained and completed questionnaires. Additional questionnaires and cultures were performed every three months for 1 year. Identified S. aureus were subjected to antimicrobial susceptibility testing as well as PCR for genes associated with tolerance to antiseptics (qacA/B, smr). Beginning in March 2020, social distancing and masking mandates were initiated. Temporary restrictions on non-essential research activities were enacted and follow-up encounters were not resumed until June 2020; subjects completed follow-up by Feb 2021. Comparison of colonization rates pre- and post-SARS-CoV-2 pandemic were performed.

Results
168 children were enrolled and 75.6% completed at least 2 follow-up encounters. 51.2% were colonized at least once by S. aureus and 8.1% had MRSA colonization (Figure 1). Those with MRSA colonization were older than those without (9.6 vs. 5.8 years, p=0.04). The frequency of S. aureus colonization was stable during the study period; however, rates of MRSA colonization declined beginning in summer 2020 (Figure 2 and 3, p=0.04). There was no difference in self-reported masking/social distancing practices or any traditional MRSA risk factors among those with and without MRSA colonization in the 6-12 month follow-up period.

The proportion of children colonized at least once during the course of the study period.

The proportion of children colonized with S. aureus at each given time point. The dashed vertical line corresponds to initiation of physical distancing/masking mandates in our region

The proportion of children colonized with MRSA at each given time point. The dashed vertical line corresponds to initiation of physical distancing/masking mandates in our region

Conclusion
Overall S. aureus nasal and axillary colonization in children remained relatively constant in the pre- and post-SARS-CoV-2 pandemic. A temporal association with social distancing/masking mandates and reduced MRSA colonization was observed. These findings suggest the potential impacts aggressive infection control practices may have on community MRSA colonization.

Disclosures
Jonathon C. McNeil, MD, Agency for Healthcare Research and Quality (Research Grant or Support)Allergan (Grant/Research Support)Nabriva (Grant/Research Support, Other Financial or Material Support, Site PI for a multicenter trial) Anthony R. Flores, MD, MPH, PhD, Nothing to disclose