Skip to main content Accessibility help

Prevalence, Prediction, and Clonality of Methicillin-Resistant Staphylococcus aureus Carriage at Admission to Medical Units in Hong Kong, China

  • Shik Luk (a1), Alex Yat Man Ho (a1), Tak Keung Ng (a1), Iris Hoi Ling Tsang (a2), Eliza Hoi Ying Chan (a2), Kin Wing Choi (a2) (a3), Ngai Chong Tsang (a4) (a5), Rodney Allan Lee (a6), Vincent Chi Chung Cheng (a7), Sau Chun Fung (a8), Wai Man Lai (a9), Tak Lun Que (a10) and Andrew Tin Yau Wong (a2)...



To determine the prevalence, risk factors, and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) colonization at the time of admission to acute medical units and to develop a cost-effective screening strategy.


Nasal and groin screening cultures were performed for patients at admission to 15 acute medical units in all 7 catchment regions in Hong Kong. All MRSA isolates were subjected to spa typing.


The overall carriage rate of MRSA was 14.3% (95% confidence interval [CI], 13.5–15.1). MRSA history within the past 12 months (adjusted odds ratio [OR], 4.60 [95% CI, 3.28–6.44]), old age home residence (adjusted OR, 3.32 [95% CI, 2.78–3.98]), and bedbound state (adjusted OR, 2.19 [95% CI, 1.75–2.74]) were risk factors selected as MRSA screening criteria that provided reasonable sensitivity (67.4%) and specificity (81.8%), with an affordable burden (25.2%). spa typing showed that 89.5% (848/948) of the isolates were clustered into the 4 spa clonal complexes (CCs): spa CC1081, spa CC032, spa CC002, and spa CC4677. Patients colonized with MRSA spa types t1081 (OR, 1.77 [95% CI, 1.49–2.09]) and t4677 (OR, 3.09 [95% CI, 1.54–6.02]) were more likely to be old age home residents.


MRSA carriage at admission to acute medical units was prevalent in Hong Kong. Our results suggest that targeted screening is a pragmatic approach to increase the detection of the MRSA reservoir. Molecular typing suggests that old age homes are epicenters in amplifying the MRSA burden in acute hospitals. Enhancement of infection control measures in old age homes is important for the control of MRSA in hospitals.


Corresponding author

12/F, Department of Pathology, Block G, Princess Margaret Hospital, Hong Kong, China (


Hide All
1. Hospital Authority. MRSA Bacteremia in HA Hospitals—2013 Ql &2013 Q2. Hong Kong: Hospital Authority, 2013. Accessed August 8, 2013.
2. Haley, CC, Mittal, D, LaViolette, A, Jannapureddy, S, Parvez, N, Haley, RW. Methicillin-resistant Staphylococcus aureus infection or colonization present at hospital admission: multivariable risk factor screening to increase efficiency of surveillance culturing. J Clin Microbiol 2007;45:30313038.
3. Koreen, L, Ramaswamy, SV, Graviss, EA, Naidich, S, Musser, JM, Kreiswirth, BN. spa typing method for discriminating among Staphylococcus aureus isolates: implications for use of a single marker to detect genetic micro- and macrovariation. J Clin Microbiol 2004;42:792799.
4. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing:21st Information Supplement. Wayne, PA: CLSI, 2011. Document M100-S21.
5. Ho, PL, Chiù, SS, Chan, MY, et al. Molecular epidemiology and nasal carriage of Staphylococcus aureus and methicillin-resistant S. aureus among young children attending day care centers and kindergartens in Hong Kong. J Infect 2012;64:500506.
6. Enright, MC, Day, NP, Davies, CE, Peacock, SJ, Spratt, BG. Mul-tilocus sequence typing for characterization of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus . J Clin Microbiol 2000;38:10081015.
7. Murchan, S, Kaufmann, ME, Deplano, A, et al. Harmonization of pulsed-field gel electrophoresis protocols for epidemiological typing of strains of methicillin-resistant Staphylococcus aureus: a single approach developed by consensus in 10 European laboratories and its application for tracing the spread of related strains. J Clin Microbiol 2003;41:15741585.
8. Eveillard, M, Ernst, C, Cuviller, S, et al. Prevalence of methicillin-resistant Staphylococcus aureus carriage at the time of admission in two acute geriatric wards. J Hosp Infect 2002;50:122126.
9. Nishikawa, M, Tanaka, T, Nakashima, K, et al. Screening for methicillin-resistant Staphylococcus aureus (MRSA) carriage on admission to a geriatric hospital. Arch Gerontol Geriatr 2009;49:242245.
10. Chang, S, Sethi, AK, Eckstein, BC, Stiefel, U, Cadnum, JL, Donskey, CJ. Skin and environmental contamination with methicillin-resistant Staphylococcus aureus among carriers identified clinically versus through active surveillance. Clin Infect Dis 2009;48:14231428.
11. Jernigan, JA, Titus, MG, Gröschel, DHM, Getchell-White, SI, Farr, BM. Effectiveness of contact isolation during a hospital outbreak of methicillin-resistant Staphylococcus aureus . Am J Epidemiol 1996;143:496504.
12. Bootsma, MC, Diekmann, O, Bonten, MJ. Controlling methicillin-resistant Staphylococcus aureus: quantifying the effects of interventions and rapid diagnostic testing. Proc Natl Acad Sci USA 2006;103:56205625.
13. Leonhardt, KK, Yakusheva, O, Phelan, D, et al. Clinical effectiveness and cost benefit of universal versus targeted methicillin-resistant Staphylococcus aureus screening upon admission in hospitals. Infect Control Hosp Epidemiol 2011;32:797803.
14. Ho, PL, Lo, PY, Chow, KH, et al. Vancomycin MIC creep in MRSA isolates from 1997 to 2008 in a healthcare region in Hong Kong. J Infect 2010;60:140145.
15. Monecke, S, Coombs, G, Shore, AC, et al. A field guide to pandemic, epidemic and sporadic clones of methicillin-resistant Staphylococcus aureus . PLoS ONE 2011;6:el7936.
16. Ho, PL, Wang, TK, Ching, P, et al. Epidemiology and genetic diversity of methicillin-resistant Staphylococcus aureus strains in residential care homes for elderly persons in Hong Kong. Infect Control Hosp Epidemiol 2007;28:671678.
17. Ho, PL, Lai, EL, Chow, KH, Chow, LSM, Yuen, KY, Yung, WH. Molecular epidemiology of methicillin-resistant Staphylococcus aureus in residential care homes for the elderly in Hong Kong. Diagn Microbiol Infect Dis 2008;61:135142.
18. Cheng, VC, Tai, JW, Wong, ZS, et al. Transmission of methicillin-resistant Staphylococcus aureus in the long term care facilities in Hong Kong. BMC Infect Dis 2013;13:205214.
19. Chen, H, Yau, C, Leung, J, Hsu, E, Ng, H, Wong, TY. Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage among residents of residential care homes for elderly (RCHE) in Hong Kong. In: 16th Annual Scientific Meeting. Hong Kong: Hong Kong Society for Infectious Diseases, 2012.


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed