Transmission of methicillin-resistant staphylococcus aureus in the long term care facilities in Hong Kong

Vincent Cc Cheng,Kris Bq Pan,Sophia Sc Chan,Denise Mk Chow,Zoie Sy Wong,Kwok-Yung Yuen,Jonathan Hk Chen,Sally Cy Wong,Pak-Leung Ho,Herman Tse,Felix Hw Chan,Kwok-Leung Tsui,Josepha Wm Tai,Miranda Cy Yau,Yizhen Hai,Wing-Chun Ng,Jasper Fw Chan

doi:10.1186/1471-2334-13-205

Abstract

BackgroundThe relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown.MethodsConcurrent MRSA screening and spa type analysis was performed in LTCFs and their network hospitals to estimate the rate of MRSA acquisition among residents during their stay in LTCFs and hospitals, by colonization pressure and MRSA transmission calculations.ResultsIn 40 LTCFs, 436 (21.6%) of 2020 residents were identified as ‘MRSA-positive’. The incidence of MRSA transmission per 1000-colonization-days among the residents during their stay in LTCFs and hospitals were 309 and 113 respectively, while the colonization pressure in LTCFs and hospitals were 210 and 185 per 1000-patient-days respectively. MRSA spa type t1081 was the most commonly isolated linage in both LTCF residents (76/121, 62.8%) and hospitalized patients (51/87, 58.6%), while type t4677 was significantly associated with LTCF residents (24/121, 19.8%) compared with hospitalized patients (3/87, 3.4%) (p < 0.001). This suggested continuous transmission of MRSA t4677 among LTCF residents. Also, an inverse linear relationship between MRSA prevalence in LTCFs and the average living area per LTCF resident was observed (Pearson correlation −0.443, p = 0.004), with the odds of patients acquiring MRSA reduced by a factor of 0.90 for each 10 square feet increase in living area.ConclusionsOur data suggest that MRSA transmission was more serious in LTCFs than in hospitals. Infection control should be focused on LTCFs in order to reduce the burden of MRSA carriers in healthcare settings.

Highlights

The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown
Our recent study showed that 46% of patients with positive MRSA screening upon hospital admission were LTCF residents [10]
Other studies focusing on the prevalence and risk factors for MRSA colonization have observed that a recent history of hospitalization is an important determinant for MRSA colonization among the population within LTCFs [8,11,12,13,14,15,16,17,18]

Summary

Introduction

The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown. Other risk factors for hospital-acquired MRSA include antibiotic exposure, length of hospital stay, admission to intensive care unit (ICU), colonization pressure, In Hong Kong, the increasing number of elderly persons urged the need for long term institutional care and frequent hospitalizations. Long term care facilities (LTCFs) providing skilled nursery services for the elderlies in Hong Kong were found to be a major reservoir for MRSA. The prevalence of MRSA carriers among LTCF residents in Hong Kong was 2.8% to 5.1% in 2005 [8,9]. Our recent study showed that 46% of patients with positive MRSA screening upon hospital admission were LTCF residents [10]. The relative contribution of LTCFs and hospitals in the degree of MRSA transmission within the healthcare setting is undetermined

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Results

Conclusion