Outbreak of MRSA in a Gynecology/Obstetrics Department during the COVID-19 Pandemic: A Cautionary Tale

Abstract

Since March 2020, the COVID-19 pandemic forced hospitals worldwide to intensify their infection control measures to prevent health care-associated transmission of SARS-CoV-2. The correct use of personal protective equipment, especially the application of masks, was quickly identified as priority to reduce transmission with this pathogen. Here, we report a nosocomial cluster of methicillin-resistant Staphylococcus aureus (MRSA) that occurred during the COVID-19 pandemic in a gynecology/obstetrics department, despite these intensified contact precautions. Five MRSA originating from clinical samples after surgical intervention led to an outbreak investigation. Firstly, this included environmental sampling of the operation theatre (OT) and, secondly, a point prevalence screening of patients and health care workers (HCW). All detected MRSA were subjected to whole genome sequencing (WGS) and isolate relatedness was determined using core genome multilocus sequence typing (cgMLST). WGS revealed one MRSA cluster with genetically closely related five patient and two HCW isolates differing in a single cgMLST allele at maximum. The outbreak was terminated after implementation of infection control bundle strategies. Although contact precaution measures, which are also part of MRSA prevention bundle strategies, were intensified during the COVID-19 pandemic, this MRSA outbreak could take place. This illustrates the importance of adherence to classical infection prevention strategies.

Keywords: COVID-19; MRSA; contact precautions; infection control; outbreak management; surgical site infection.

Figure 1

Minimum spanning tree of detected MRSA in chronological order. Minimum spanning tree of five healthcare worker (HCW) and five patient (P) isolates illustrating their genotypic relationship based on up to 1861 cgMLST target genes, pairwise ignore missing values. Every circle represents one genotype, the size of circles correlates with the number of identical genotypes. Color of circles indicates MRSA spa-type. Grey coloring indicates close genetic relation.