Edward Stenehjem1, David Rimland. 1. Atlanta Veterans Affairs Medical Center, Decatur, GA, USA. eddie.stenehjem@imail.org
Abstract
BACKGROUND: Staphylococcus aureus nasal colonization burden has been identified as a risk factor for infection. This study evaluates methicillin-resistant S aureus (MRSA) nasal burden, as defined by the cycle threshold (Ct) and risk of subsequent infection. METHODS: In a retrospective cohort study, United States veterans were classified into 3 MRSA nasal colonization groups: noncarriers, low burden (Ct > 24 cycles), and high burden (Ct ≤ 24 cycles). MRSA infections were identified prospectively, and clinical information was obtained by chart review. Multivariate logistic regression assessed the association of MRSA nasal burden and risk of MRSA infection. RESULTS: During 4-years of follow-up, 4.3% of noncarriers, 18.5% of low burden, and 17.2% of high burden developed a MRSA infection. In multivariate analysis, MRSA nasal colonization was a risk factor for MRSA infection (P = .008) with low burden (risk ratio [RR], 3.62; 95% confidence interval [CI]: 1.47-8.93) and high burden (RR, 2.71; 95% CI: 0.95-7.72) associated with subsequent MRSA infection when compared with noncarriers. When compared with low burden, high burden nasal carriers were not at increased risk of infection (RR, 0.75; 95% CI 0.36-1.55). CONCLUSION: MRSA nasal colonization was a risk factor for MRSA infection. High nasal burden of MRSA did not increase the risk of infection.
BACKGROUND:Staphylococcus aureus nasal colonization burden has been identified as a risk factor for infection. This study evaluates methicillin-resistant S aureus (MRSA) nasal burden, as defined by the cycle threshold (Ct) and risk of subsequent infection. METHODS: In a retrospective cohort study, United States veterans were classified into 3 MRSA nasal colonization groups: noncarriers, low burden (Ct > 24 cycles), and high burden (Ct ≤ 24 cycles). MRSA infections were identified prospectively, and clinical information was obtained by chart review. Multivariate logistic regression assessed the association of MRSA nasal burden and risk of MRSA infection. RESULTS: During 4-years of follow-up, 4.3% of noncarriers, 18.5% of low burden, and 17.2% of high burden developed a MRSA infection. In multivariate analysis, MRSA nasal colonization was a risk factor for MRSA infection (P = .008) with low burden (risk ratio [RR], 3.62; 95% confidence interval [CI]: 1.47-8.93) and high burden (RR, 2.71; 95% CI: 0.95-7.72) associated with subsequent MRSA infection when compared with noncarriers. When compared with low burden, high burden nasal carriers were not at increased risk of infection (RR, 0.75; 95% CI 0.36-1.55). CONCLUSION: MRSA nasal colonization was a risk factor for MRSA infection. High nasal burden of MRSA did not increase the risk of infection.
Authors: L A Mermel; S J Eells; M K Acharya; J M Cartony; D Dacus; S Fadem; E A Gay; S Gordon; J R Lonks; T M Perl; L K McDougal; J E McGowan; G Maxey; D Morse; F C Tenover Journal: Infect Control Hosp Epidemiol Date: 2010-06 Impact factor: 3.254
Authors: Heiman F L Wertheim; Damian C Melles; Margreet C Vos; Willem van Leeuwen; Alex van Belkum; Henri A Verbrugh; Jan L Nouwen Journal: Lancet Infect Dis Date: 2005-12 Impact factor: 25.071
Authors: A L Panlilio; D H Culver; R P Gaynes; S Banerjee; T S Henderson; J S Tolson; W J Martone Journal: Infect Control Hosp Epidemiol Date: 1992-10 Impact factor: 3.254
Authors: Stefanie Baur; Maren Rautenberg; Michaela Faulstich; Manuela Faulstich; Timo Grau; Yannik Severin; Clemens Unger; Wolfgang H Hoffmann; Thomas Rudel; Ingo B Autenrieth; Christopher Weidenmaier Journal: PLoS Pathog Date: 2014-05-01 Impact factor: 6.823
Authors: Urs-Vito Albrecht; Ute von Jan; Ludwig Sedlacek; Stephanie Groos; Sebastian Suerbaum; Ralf-Peter Vonberg Journal: J Med Internet Res Date: 2013-08-14 Impact factor: 5.428
Authors: Michael R Yeaman; Scott G Filler; Clint S Schmidt; Ashraf S Ibrahim; John E Edwards; John P Hennessey Journal: Front Immunol Date: 2014-09-26 Impact factor: 7.561