S-C Wong1, J H-K Chen2, S Y-C So2, P-L Ho3, K-Y Yuen3, V C-C Cheng4. 1. Infection Control Team, Queen Mary Hospital, Hong Kong West Cluster, Hong Kong Special Administrative Region, China. 2. Department of Microbiology, Queen Mary Hospital, Hong Kong Special Administrative Region, China. 3. Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China. 4. Infection Control Team, Queen Mary Hospital, Hong Kong West Cluster, Hong Kong Special Administrative Region, China; Department of Microbiology, Queen Mary Hospital, Hong Kong Special Administrative Region, China. Electronic address: vcccheng@hku.hk.
Abstract
BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) has become endemic in many healthcare settings. AIM: To analyse the incidence, risk factors, outcomes, and genomic relatedness of patients with newly diagnosed gastrointestinal colonization of MRSA. METHODS: Epidemiology and genetic analysis by whole-genome sequencing (WGS) in a hospital network in Hong Kong. FINDINGS: Between October 1st, 2015 and December 31st, 2018, a total of 919 (2.7%) of 34,667 patients had newly diagnosed gastrointestinal MRSA colonization by admission screening. The incidence was 0.67 ± 0.32 per 1000 patient-days per quarter. Including patients with gastrointestinal MRSA colonization, the overall burden of MRSA increased by 59.2%, with an addition of 4727 MRSA patient-days during the study period. Patients referred from residential care home for the elderly, with history of hospitalization in the past six months, and consumption of fluoroquinolones, cephalosporins, and proton-pump inhibitors in the preceding six months were found to be independent risk factors by multivariate analysis in the case-control analysis. The median survival of cases was significantly shorter than that of controls (860 vs 1507 days, P < 0.001). Of 919 patients, 127 (13.8%) developed symptomatic MRSA infection in a median of 112 days. Of 19 patients with paired MRSA faecal and blood culture isolates subjected to WGS, clonality was found in 16 (84.2%) pairs of MRSA isolates. MRSA ST45 constituted 44.7% (17/38) of MRSA isolates. CONCLUSION: Gastrointestinal MRSA colonization may contribute to adverse clinical outcomes and pose an unrecognized burden upon hospital infection control.
BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) has become endemic in many healthcare settings. AIM: To analyse the incidence, risk factors, outcomes, and genomic relatedness of patients with newly diagnosed gastrointestinal colonization of MRSA. METHODS: Epidemiology and genetic analysis by whole-genome sequencing (WGS) in a hospital network in Hong Kong. FINDINGS: Between October 1st, 2015 and December 31st, 2018, a total of 919 (2.7%) of 34,667 patients had newly diagnosed gastrointestinal MRSA colonization by admission screening. The incidence was 0.67 ± 0.32 per 1000 patient-days per quarter. Including patients with gastrointestinal MRSA colonization, the overall burden of MRSA increased by 59.2%, with an addition of 4727 MRSA patient-days during the study period. Patients referred from residential care home for the elderly, with history of hospitalization in the past six months, and consumption of fluoroquinolones, cephalosporins, and proton-pump inhibitors in the preceding six months were found to be independent risk factors by multivariate analysis in the case-control analysis. The median survival of cases was significantly shorter than that of controls (860 vs 1507 days, P < 0.001). Of 919 patients, 127 (13.8%) developed symptomatic MRSA infection in a median of 112 days. Of 19 patients with paired MRSA faecal and blood culture isolates subjected to WGS, clonality was found in 16 (84.2%) pairs of MRSA isolates. MRSA ST45 constituted 44.7% (17/38) of MRSA isolates. CONCLUSION: Gastrointestinal MRSA colonization may contribute to adverse clinical outcomes and pose an unrecognized burden upon hospital infection control.