Proportions of <i>Staphylococcus aureus</i> and Methicillin-Resistant <i>Staphylococcus aureus</i> in Patients with Surgical Site Infections in Mainland China: A Systematic Review and Meta-Analysis

<div><p>Background</p><p>Sufficient details have not been specified for the epidemiological characteristics of <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) among surgical site infections (SSIs) in mainland China. This systematic review aimed to estimate proportions of <i>S. aureus</i> and MRSA in SSIs through available published studies.</p><p>Methods</p><p>PubMed, Embase and four Chinese electronic databases were searched to identify relevant primary studies published between 2007 and 2012. Meta-analysis was conducted on the basis of logit-transformed metric for proportions of <i>S. aureus</i> and MRSA, followed by pre-defined subgroup meta-analysis. Random-effects meta-regression was also conducted to explore the impact of possible factors on <i>S. aureus</i> proportions.</p><p>Results</p><p>106 studies were included, of which 38 studies involved MRSA. <i>S. aureus</i> accounted for 19.1% (95%CI 17.2-21.0%; I² = 84.1%) of all isolates in SSIs, which was roughly parallel to 18.5% in the United States (US) (P-value = 0.57) but significantly exceeded those calculated through the surveillance system in China (P-value<0.001). In subgroup analysis, <i>S. aureus</i> in patients with thoracic surgery (41.1%, 95%CI 26.3-57.7%; I² = 74.4%) was more common than in those with gynecologic surgery (20.1%, 95%CI 15.6-25.6%; I² = 33.0%) or abdominal surgery (13.8%, 95%CI 10.3-18.4%; I² = 70.0%). Similar results were found in meta-regression. MRSA accounted for 41.3% (95%CI 36.5-46.3%; I² = 64.6%) of <i>S. aureus</i>, significantly lower than that in the US (P-value = 0.001). MRSA was sensitive to vancomycin (522/522) and linezolid (93/94), while 79.9% (95%CI 67.4-88.4%; I² = 0%) and 92.0% (95%CI 80.2-97.0%; I² = 0%) of MRSA was resistant to clindamycin and erythromycin respectively.</p><p>Conclusion</p><p>The overall proportion of <i>S. aureus</i> among SSIs in China was similar to that in the US but seemed higher than those reported through the Chinese national surveillance system. Proportions of <i>S. aureus</i> SSIs may vary with different surgery types. Commonly seen in SSIs, MRSA tended to be highly sensitive to vancomycin and linezolid but mostly resistant to clindamycin and erythromycin.</p></div

General information of all the included studies.

<p>* In this column multiple surgeries refer to the different kinds of surgeries involved in the study which cannot be discriminated or classified into a specific type of surgery.</p><p>General information of all the included studies.</p

Overall proportion of <i>S. aureus</i> in patients with SSIs.

<p>Overall proportion of <i>S. aureus</i> in patients with SSIs.</p

Flow diagram of study inclusion.

<p>Flow diagram of study inclusion.</p

Province distribution of proportions of <i>S. aureus</i> isolates in China.

<p>Province distribution of proportions of <i>S. aureus</i> isolates in China.</p

Overall proportion of MRSA in patients with <i>S. aureus</i> SSIs.

<p>Overall proportion of MRSA in patients with <i>S. aureus</i> SSIs.</p

Summary of the pooled results of proportions of <i>S. aureus</i> and MRSA isolates.

<p>* Others refer to: 1) multiple surgeries involved in the study which cannot be classified into a specific type of surgery or 2) a specific type of surgery, rather than orthopedic, abdominal, gynecologic, or thoracic surgeries, which was reported in a small number of studies.</p><p>** Non-retrospective design comprises prospective, cross-sectional, ambispective study and surveillance.</p><p>*** Sample size in the proportions of <i>S. aureus</i> isolates refers to the number of all the detected bacteria isolates; in the proportions of MRSA it refers to the number of all <i>S. aureus</i> isolates.</p><p>Summary of the pooled results of proportions of <i>S. aureus</i> and MRSA isolates.</p

Summary results of meta-regression for the proportion of <i>S. aureus</i> isolates.

<p>Summary results of meta-regression for the proportion of <i>S. aureus</i> isolates.</p

Additional file 1: of Incidence, temporal trend and factors associated with ventilator-associated pneumonia in mainland China: a systematic review and meta-analysis

Table S1. Search strategies and results. Table S2. List of all the included studies. Table S3. General information of all the included studies. Table S4. The results of subgroup analyses by Chinese provinces and years of study. Table S5. Summary of diagnostic requirements for the three published sets of criteria in mainland China. Figure S1. Forest plot of the cumulative incidence of ventilator-associated pneumonia using a random-effects model. Figure S2. Forest plot of the incidence density (reported as episodes per 1000 ventilator-days) of ventilator-associated pneumonia using a random-effects model. Figure S3. Forest plot of the incidence density (reported as patients per 1000 ventilator-days) of ventilator-associated pneumonia using a random-effects model. (PDF 2137 kb