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Nasal Swab Screening for Methicillin-Resistant Staphylococcus aureus—How Well Does It Perform? A Cross-Sectional Study

Published online by Cambridge University Press:  02 January 2015

Ann Matheson
Affiliation:
Health Protection Scotland, Glasgow, United Kingdom
Peter Christie*
Affiliation:
Healthcare Improvement Scotland, Edinburgh, United Kingdom
Traiani Stari
Affiliation:
University of Strathclyde, Glasgow, United Kingdom
Kim Kavanagh
Affiliation:
University of Strathclyde, Glasgow, United Kingdom
Ian M. Gould
Affiliation:
National Health Service (NHS) Grampian Health Board, Aberdeen, United Kingdom
Robert Masterton
Affiliation:
NHS Ayrshire and Arran Health Board, Ayrshire, United Kingdom
Jacqui S. Reilly
Affiliation:
Health Protection Scotland, Glasgow, United Kingdom Glasgow Caledonian University, Glasgow, United Kingdom
*
Healthcare Improvement Scotland, Elliott House, 8-10 Hillside Crescent, Edinburgh EH7 5EA, United Kingdom ([email protected])

Abstract

Objective.

To determine the proportion of methicillin-resistant Staphylococcus aureus (MRSA) detections identified by nasal swabbing using agar culture in comparison with multiple body site testing using agar and nutrient broth culture.

Design.

Cross-sectional study.

Patients.

Adult patients admitted to 36 general specialty wards of 2 large hospitals in Scotland.

Methods.

Patients were screened for MRSA via multiple body site swabs (nasal, throat, axillary, perineal, and wound/invasive device sites) cultured individually on chromogenic agar and pooled in nutrient broth. Combined results from all sites and cultures provided a gold-standard estimate of true MRSA prevalence.

Results.

This study found that nasal screening performed better than throat, axillary, or perineal screening but at best identified only 66% of true MRSA carriers against the gold standard at an overall prevalence of 2.9%. Axillary screening performed least well. Combining nasal and perineal swabs gave the best 2-site combination (82%). When combined with realistic screening compliance rates of 80%–90%, nasal swabbing alone probably detects just over half of true colonization in practice. Swabbing of clinically relevant sites (wounds, indwelling devices, etc) is important for a small but high-prevalence group.

Conclusions.

Nasal swabbing is the standard method in many locations for MRSA screening. Its diagnostic efficiency in practice appears to be limited, however, and the resource implications of multiple body site screening have to be balanced against a potential clinical benefit whose magnitude and nature remains unclear.

Type
Original Article
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2012

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References

1.Reilly, J, Stewart, S, Allardice, GA, et al. Results from the Scottish National HAI Prevalence Survey. J Hosp Infect 2008;69:6268.Google Scholar
2.Cosgrove, SE, Sakoulas, G, Perencevich, EN, Schwaber, MJ, Karch-mer, AW, Carmeli, Y. Comparison of mortality associated with methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteremia: a meta-analysis. Clin Infect Dis 2003;36: 5359.Google Scholar
3.Cosgrove, SE, Qi, Y, Kaye, KS, Harbarth, S, Karchmer, AW, Carmeli, Y. The impact of methicillin resistance in Staphylococcus aureus bacteremia on patient outcomes: mortality, length of stay, and hospital charges. Infect Control Hosp Epidemiol 2005;26:166174.Google Scholar
4.Gould, IM. Costs of hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) and its control. Int J Antimicrob Agents 2006;28:379384.CrossRefGoogle ScholarPubMed
5.Kang, CI, Song, JH, Chung, DR, et al. Clinical impact of methicillin resistance on outcome of patients with Staphylococcus aureus infection: a stratified analysis according to underlying diseases and sites of infection in a large prospective cohort. J Infect 2010;61:299306.Google Scholar
6.Lipsky, BA, Weigelt, JA, Gupta, V, Killian, A, Peng, MM. Skin, soft tissue, bone, and joint infections in hospitalized patients: epidemiology and microbiological, clinical, and economic outcomes. Infect Control Hosp Epidemiol 2007;28:12901298.CrossRefGoogle ScholarPubMed
7.Rieg, S, Peyerl-Hoffmann, G, de With, K, et al. Mortality of S. aureus bacteremia and infectious diseases specialist consultation—a study of 521 patients in Germany. J Infect 2009;59: 232239.Google Scholar
8.Weigelt, JA, Lipsky, BA, Tabak, YR, Derby, KG, Kim, M, Gupta, V. Surgical site infections: causative pathogens and associated outcomes. Am J Infect Control 2010;38:112120.Google Scholar
9.Wyllie, DH, Peto, TE, Crook, D. MRSA bacteraemia in patients on arrival in hospital: a cohort study in Oxfordshire 1997–2003. BMJ 2005;331:992.Google Scholar
10.Reilly, JS, Stewart, S, Christie, P, et al. Universal screening for meticillin-resistant Staphylococcus aureus in acute care: risk factors and outcome from a multicentre study. J Hosp Infect 2012;80:3135.Google Scholar
11.Huang, SS, Piatt, R. Risk of methicillin-resistant Staphylococcus aureus infection after previous infection or colonization. Clin Infect Dis 2003;36:281285.Google Scholar
12.Health Protection Scotland on behalf of Pathfinder Health Boards. Final Report Volume 1: An Investigation of the Clinical Effectiveness of MRSA Screening. Glasgow: Health Protection Scotland, 2009. http://www.documents.hps.scot.nhs.uk/hai/mrsa-screening/pathfinder-programme/mrsa-pathfinder-voll-2011-02-23.pdf. Accessed May 1, 2012.Google Scholar
13.Ritchie, K, Craig, J, Eastgate, J, et al. The Clinical and Cost Effectiveness of Screening for Meticillin-Resistant Staphylococcus aureus (MRSA). Edinburgh: National Health Service Quality Improvement Scotland, 2007.Google Scholar
14.Acton, DS, Plat-Sinnige, MJ, van Wamel, W, de Groot, N, van Bel-kum, A. Intestinal carriage of Staphylococcus aureus: how does its frequency compare with that of nasal carriage and what is its clinical impact? Eur J Clin Microbiol Infect Dis 2009;28:115127.Google Scholar
15.Bitterman, Y, Laor, A, Itzhaki, S, Weber, G. Characterization of the best anatomical sites in screening for methicillin-resistant Staphylococcus aureus colonization. Eur J Clin Microbiol Infect Dis 2010;29:391397.Google Scholar
16.Coello, R, Glynn, JR, Gaspar, C, Picazo, JJ, Fereres, J. Risk factors for developing clinical infection with methicillin-resistant Staphylococcus aureus (MRSA) amongst hospital patients initially only colonized with MRSA. J Hosp Infect 1997;37:3946.Google Scholar
17.Harbarth, S, Schrenzel, J, Renzi, G, Akakpo, C, Ricou, B. Is throat screening necessary to detect methicillin-resistant Staphylococcus aureus colonization in patients upon admission to an intensive care unit? J Clin Microbiol 2007;45:10721073.CrossRefGoogle Scholar
18.Lautenbach, E, Nachamkin, I, Hu, B, et al. Surveillance cultures for detection of methicillin-resistant Staphylococcus aureus: diagnostic yield of anatomic sites and comparison of provider-and patient-collected samples, infect Control Hosp Epidemiol 2009;30:380382.Google Scholar
19.Mermel, LA, Eells, SJ, Acharya, MK, et al. Quantitative analysis and molecular fingerprinting of methicillin-resistant Staphylococcus aureus nasal colonization in different patient populations: a prospective, multicenter study. Infect Control Hosp Epidemiol 2010;31:592597.CrossRefGoogle ScholarPubMed
20.Meurman, O, Routamaa, M, Peltonen, R. Screening for methicillin-resistant Staphylococcus aureus: which anatomical sites to culture? J Hosp Infect 2005;61:351353.Google Scholar
21.Batra, R, Eziefula, AC, Wyncoll, D, Edgeworth, J. Throat and rectal swabs may have an important role in MRSA screening of critically ill patients. Intensive Care Med 2008;34:17031706.Google Scholar
22.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.Google Scholar
23.Adults with Incapacity (Scotland) Act 2000. Edinburgh: Scottish Government, 2000.Google Scholar
24.Health Protection Scotland. NHS Scotland MRSA Screening Pathfinder Programme: Interim Report. Glasgow: Health Protection Scotland, 2009.Google Scholar
25.Grmek-Kosnik, I, Ihan, A, Dermota, U, Rems, M, Kosnik, M, Jorn, KH. Evaluation of separate vs pooled swab cultures, different media, broth enrichment and anatomical sites of screening for the detection of methicillin-resistant Staphylococcus aureus from clinical specimens. J Hosp Infect 2005;61:155161.Google Scholar
26.Coello, R, Jimenez, J, Garcia, M, et al. Prospective study of in fection, colonization and carriage of methicillin-resistant Staphylococcus aureus in an outbreak affecting 990 patients. Eur J Clin Microbiol Infect Dis 1994;13:7481.Google Scholar
27.Eveillard, M, Leroy, C, Teissiere, F, et al. Impact of selective screening in the emergency department on meticillin-resistant Staphylococcus aureus control programmes. J Hosp Infect 2006;63: 380384.Google Scholar
28.Lee, BY, Bailey, RR, Smith, KJ, et al. Universal methicillin-resistant Staphylococcus aureus (MRSA) surveillance for adults at hospital admission: an economic model and analysis. Infect Control Hosp Epidemiol 2010;31:598606.Google Scholar
29.Health Protection Scotland. Discharge Testing for MRSA in Scottish Hospitals: MRSA Acquisition, Description of Acquired Strains and Risk Factors for Acquisition of MRSA in the Hospital Glasgow Health Protection Scotland, 2010. http://www.documents.hps.scot.nhs.uk/hai/mrsa-screening/pathfinder-programme/mrsa-pathfinder-discharge-2011-03-18.pdf. Accessed May 1, 2012.Google Scholar
30.Health Protection Scotland. NHS Scotland MRSA Screening Pathfinder Programme: The Value of Nasal Swabbing versus Full Body Screening or Clinical Risk Assessment to Detect MRSA Colonisation at Admission to Hospital Glasgow: Health Protection Scotland, 2011. http://www.documents.hps.scot.nhs.uk/hai/mrsa-screening /pathfinder-programme/mrsa-pathfinder-admissions-2011-02-23.pdf. Accessed May 1, 2012.Google Scholar