human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background . Although risk factors for surgical site infection ( SSI ) after cardiovascular ( CV ) surgery have been well-documented among adults , few studies have been conducted in children . We performed a case-control study to identify risk factors for hospitalized SSI in children undergoing CV surgery .  Methods . National Nosocomial Infections Surveillance System criteria were used prospect ively to identify cases of hospitalized SSI in patients who underwent CV surgery . Seventy-nine patients who underwent CV surgery without hospitalized SSI were r and omly selected as controls . Cases were compared with controls to determine preoperative , intraoperative and postoperative risk factors for hospitalized SSI . Multivariable logistic regression was performed . Results . An SSI developed in 19 of the 826 patients who underwent CV surgery  ( 2.3 cases per 100 surgeries ) during the study period . Infection was limited to soft tissue in 12 , whereas deeper infection occurred in 7 . Causative agents included Staphylococcus aureus ( 11 ) , coagulase-negative Staphylococcus ( 5 ) and Escherichia coli ( 2 ) . One patient did not have a pathogen isolated . In a multivariable analysis , duration of surgery ( odds ratio , 1.4 ; 95 % confidence interval , 1.2 to 1.8 ) and age < 1 month ( odds ratio , 14 ; 95 % confidence interval , 3.3 to 58.4 ) were independently associated with SSI . Conclusions . Age < 1 month and longer duration of surgery were independently associated with hospitalized SSI after CV surgery in children A prospect i ve open-cohort study was performed in 838 adults undergoing coronary revascularization or valve surgery  to define the risk factors for development of surgical site infections . Patients diagnosed with mediastinitis or endocarditis during follow-up were compared with patients with no such infection . After 1 year of follow-up , 22 ( 2.6 % ) patients had developed mediastinitis or endocarditis . No preoperative or intraoperative variables were identified as risk factors . By multivariate analysis of postoperative variables , respiratory insufficiency , microorganisms in blood cultures , and intensive care unit stay were independent risk factors for the development of these complications . The type of antibiotic prophylaxis had no influence on the incidence of organ or space infections after cardiac surgery OBJECTIVES To identify risk factors for  surgical site infection ( SSI ) in older people and to test a priori hypotheses regarding particular variables and SSI risk . DESIGN Case-control study . SETTING Duke University Medical Center and seven community hospitals in North Carolina and Virginia . PARTICIPANTS Elderly patients ( > or = 65 ) who underwent surgery between 1991 and 2002 at the study hospitals . Cases were elderly patients with SSI ; controls were elderly operative patients without SSI . Infection control practitioners prospect ively identified patients . MEASUREMENTS Data were collected retrospectively . Case patients who developed SSI were compared with control patients who did not develop SSI . RESULTS Five hundred sixty-nine SSI cases were identified , and 589 uninfected controls were selected . In multivariate analysis , independent predictors of SSI included obesity ( odds ratio (OR)=1.77 , 95 % confidence interval (CI)=1.34 - 2.32 ) , chronic obstructive pulmonary disease ( COPD ) ( OR=1.66 , 95 % CI=1.17 - 2.34 ) , and a wound class classified as contaminated or dirty ( OR=1.65 , 95 % CI=1.01 - 2.72 ) . Having private insurance was associated with lower risk ( OR=0.29 , 95 % CI=0.12 - 0.68 ) . CONCLUSION This study identified several independent predictors of  SSI in older people , including comorbid conditions ( COPD and obesity ) , perioperative variables ( wound class ) , and socioeconomic factors ( private insurance , which was associated with lower risk ) . The results from this study can be used to design and implement interventions for SSI prevention in high-risk older people Purpose To investigate the incidence and risk factors associated with the development of  surgical site infections ( SSIs ) using the National Nosocomial Infection Surveillance ( NNIS ) . Methods A prospect i ve cohort study was conducted at a tertiary health care center . Infection control personnel collected general and health care related data about patients . The NNIS risk index was calculated on the basis of data relating to the operation : wound contamination class , duration of surgery , and the American Society of Anesthesiologists ( ASA ) score . Results A total of 5109 surgical procedures were included in the study . The overall cumulative incidence rate was 6.3 % . The incidence of SSIs was 2.3 % ( 63.5 % of operative procedures ) , 8.3 % ( 29.7 % ) , 34.6 % ( 6.2 % ) , and 43.3 % ( 0.6 % ) , in patients with 0 , 1 , 2 , and 3 risk index , respectively . The length of hospital stay ( OR : 1.0 ; 95 % CI : 1.053–1.075 ) , preoperative length of stay ( odds ratio [ OR ] : 1.9 ; 95 % confidence interval [ CI ] : 1.953–1.981 ) , antibiotic prophylaxis ( OR : 2.5 ; 95 % CI : 1.421–4.628 ) , drainage ( OR : 1.7 ; 95 % CI : 1.360–2.353 ) , ASA score ( OR : 1.5 ; 95 % CI : 1.235–1.946 ) , class of wound contamination ( OR : 2.0 ; 95 % CI : 1.745–2.003 ) , and NNIS risk index ( OR : 1.3 ; 95 % CI : 1.063–1.7 ) were independently associated with an increased risk for SSIs . Staphylococcus aureus was the most frequently isolated microorganism , 64 % of them being methicillin-resistant . Conclusion The aim of this study was to investigate the most important risk factors associated with the development of surgical site infections ( SSIs ) . Therefore , greater attention has been given to adherence to recommendations for the prevention and control of SSIs as well as to antibiotic prophylaxis protocol OBJECTIVE To identify risk factors associated with surgical-site infection according to the depth of infection , the cardiac procedure , and the National Nosocomial Infections Surveillance System risk index . DESIGN Prospect i ve survey conducted during a 12-month period . SETTING A 48-bed cardiac surgical department in a teaching hospital . PATIENTS Patients admitted for cardiac surgery between February 2002 and January 2003 . RESULTS Surgical-site infections were diagnosed in 3 % of the patients ( 38 of 1,268 ) . Of the 38 surgical-site infections , 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6 % and 1.4 % , respectively . Cultures were positive in 28 cases and the most commonly isolated pathogen was Staphylococcus . A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection ( relative risk , 2.4 ; P < .004 ) . Heart transplantation , mechanical circulatory assistance , coronary artery bypass graft with the use of internal mammary artery , and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection . CONCLUSIONS Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts . Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis . Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection , and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection OBJECT The purpose of this study was to determine the incidence rate and risk factors of surgical site infections ( SSIs ) in neurosurgery for any type of surgery and any American Society of Anesthesiologists class . METHODS The authors undertook an exhaustive 18-month prospect i ve survey including patients who underwent neurosurgery .  In particular , a 30-day follow-up was completed in patients whose surgery did not involve placement of a prosthesis or implant , and 1-year follow-up was completed for patients who underwent surgery to place a prosthesis or implant . The Centers for Disease Control definition of SSI was used . Univariate and multivariate analyses were conducted ; all dependent variables found in univariate analysis were entered in the multiple regression model . A stepwise multiple logistic regression method was used . RESULTS Of the 844 patients studied , 35 SSIs were diagnosed , yielding an incidence rate of 4.1 % ( 95 % confidence interval 3.6 - 4.5 ) . Independent predictive risk factors for infection were cerebrospinal fluid leakage , external shunt , Altemeier class , and further neurosurgery . A lack of antibiotic prophylaxis was not found to be a risk factor . CONCLUSIONS Infection risk factors occur mainly during the postoperative period Background Although nasal carriage of MRSA has been identified as one of the risk factors for surgical site infection ( SSI ) with MRSA , there have been no reports of this in the orthopedics field . Methods This prospect i ve observational cohort study included 2,423 consecutive patients who were admitted to our department over 26 months and who underwent orthopedic surgery .  We examined the relationship between pre-existing nasal MRSA and subsequent occurrence of SSI with MRSA . Results 63 patients ( 2.6 % ) had a positive nasal MRSA culture . 15 patients ( 0.6 % ) developed SSI with MRSA . The occurrence of SSI with MRSA in nasal MRSA carriers was significantly higher than that in non-carriers ( 4 out of 63 ( 6.3 % ) vs. 11 out of 2,360 ( 0.5 % ) ; p < 0.001 ) ( adjusted OR : 11 ; 95 % CI : 3–37 ; p = 0.001 ) . Interpretation We recommend appropriate treatment of patients who are nasal carriers of MRSA before orthopedic surgery Background Surgical site infection ( SSI ) continues to be a major source of morbidity and mortality in developing countries despite recent advances in aseptic techniques . There is no baseline information regarding SSI in our setting therefore it was necessary to conduct this study to establish the prevalence , pattern and predictors of surgical site infection at Bug and o Medical Centre Mwanza ( BMC ) , Tanzania . Methods This was a cross-sectional prospect i ve study involving all patients who underwent major surgery in surgical wards between July 2009 and March 2010 . After informed written consent for the study and HIV testing , all patients who met inclusion criteria were consecutively enrolled into the study . Pre-operative , intra-operative and post operative data were collected using st and ardized data collection form . Wound specimens were collected and processed as per st and ard operative procedures ; and susceptibility testing was done using disc diffusion technique . Data were analyzed using SPSS software version 15 and STATA . Results Surgical site infection ( SSI ) was detected in 65 ( 26.0 % ) patients , of whom 56 ( 86.2 % ) and 9 ( 13.8 % ) had superficial and deep SSI respectively . Among 65 patients with clinical SSI  , 56(86.2 % ) had positive aerobic culture . Staphylococcus aureus was the predominant organism 16/56 ( 28.6 % ) ; of which 3/16 ( 18.8 % ) were MRSA . This was followed by Escherichia coli 14/56 ( 25 % ) and Klebsiella pneumoniae 10/56 ( 17.9 % ) . Among the Escherichia coli and Klebsiella pneumoniae isolates 9(64.3 % ) and 8(80 % ) were ESBL producers respectively . A total of 37/250 ( 14.8 % ) patients were HIV positive with a mean CD4 count of 296 cells/ml . Using multivariate logistic regression analysis , presence of pre-morbid illness ( OR = 6.1 ) , use of drain ( OR = 15.3 ) , use of iodine alone in skin preparation ( OR = 17.6 ) , duration of operation ≥ 3 hours ( OR = 3.2 ) and cigarette smoking ( OR = 9.6 ) significantly predicted surgical site infection ( SSI ) ConclusionS SI is common among patients admitted in surgical wards at BMC and pre-morbid illness , use of drain , iodine alone in skin preparation , prolonged duration of the operation and cigarette smoking were found to predict SSI . Prevention strategies focusing on factors associated with SSI is necessary in order to reduce the rate of SSI in our setting Background Sternal wound infection ( SWI ) is an uncommon but potentially life-threatening complication of cardiac surgery . Predisposing factors for SWI are multiple with varied frequencies in different studies . The purpose of this study was to assess the incidence , risk factors , and mortality of SWI after  coronary artery bypass grafting ( CABG ) at Tehran Heart Center . Methods This study prospect ively evaluated multiple 
    Output:
    
agent
AND RELEVANCE In a broad review of published literature , risk factors for SSI were characterized as describing reduced fitness , patient frailty , surgery duration , and complexity .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background . Although risk factors for surgical site infection ( SSI ) after cardiovascular ( CV ) surgery have been well-documented among adults , few studies have been conducted in children . We performed a case-control study to identify risk factors for hospitalized SSI in children undergoing CV surgery .  Methods . National Nosocomial Infections Surveillance System criteria were used prospect ively to identify cases of hospitalized SSI in patients who underwent CV surgery . Seventy-nine patients who underwent CV surgery without hospitalized SSI were r and omly selected as controls . Cases were compared with controls to determine preoperative , intraoperative and postoperative risk factors for hospitalized SSI . Multivariable logistic regression was performed . Results . An SSI developed in 19 of the 826 patients who underwent CV surgery  ( 2.3 cases per 100 surgeries ) during the study period . Infection was limited to soft tissue in 12 , whereas deeper infection occurred in 7 . Causative agents included Staphylococcus aureus ( 11 ) , coagulase-negative Staphylococcus ( 5 ) and Escherichia coli ( 2 ) . One patient did not have a pathogen isolated . In a multivariable analysis , duration of surgery ( odds ratio , 1.4 ; 95 % confidence interval , 1.2 to 1.8 ) and age < 1 month ( odds ratio , 14 ; 95 % confidence interval , 3.3 to 58.4 ) were independently associated with SSI . Conclusions . Age < 1 month and longer duration of surgery were independently associated with hospitalized SSI after CV surgery in children A prospect i ve open-cohort study was performed in 838 adults undergoing coronary revascularization or valve surgery  to define the risk factors for development of surgical site infections . Patients diagnosed with mediastinitis or endocarditis during follow-up were compared with patients with no such infection . After 1 year of follow-up , 22 ( 2.6 % ) patients had developed mediastinitis or endocarditis . No preoperative or intraoperative variables were identified as risk factors . By multivariate analysis of postoperative variables , respiratory insufficiency , microorganisms in blood cultures , and intensive care unit stay were independent risk factors for the development of these complications . The type of antibiotic prophylaxis had no influence on the incidence of organ or space infections after cardiac surgery OBJECTIVES To identify risk factors for  surgical site infection ( SSI ) in older people and to test a priori hypotheses regarding particular variables and SSI risk . DESIGN Case-control study . SETTING Duke University Medical Center and seven community hospitals in North Carolina and Virginia . PARTICIPANTS Elderly patients ( > or = 65 ) who underwent surgery between 1991 and 2002 at the study hospitals . Cases were elderly patients with SSI ; controls were elderly operative patients without SSI . Infection control practitioners prospect ively identified patients . MEASUREMENTS Data were collected retrospectively . Case patients who developed SSI were compared with control patients who did not develop SSI . RESULTS Five hundred sixty-nine SSI cases were identified , and 589 uninfected controls were selected . In multivariate analysis , independent predictors of SSI included obesity ( odds ratio (OR)=1.77 , 95 % confidence interval (CI)=1.34 - 2.32 ) , chronic obstructive pulmonary disease ( COPD ) ( OR=1.66 , 95 % CI=1.17 - 2.34 ) , and a wound class classified as contaminated or dirty ( OR=1.65 , 95 % CI=1.01 - 2.72 ) . Having private insurance was associated with lower risk ( OR=0.29 , 95 % CI=0.12 - 0.68 ) . CONCLUSION This study identified several independent predictors of  SSI in older people , including comorbid conditions ( COPD and obesity ) , perioperative variables ( wound class ) , and socioeconomic factors ( private insurance , which was associated with lower risk ) . The results from this study can be used to design and implement interventions for SSI prevention in high-risk older people Purpose To investigate the incidence and risk factors associated with the development of  surgical site infections ( SSIs ) using the National Nosocomial Infection Surveillance ( NNIS ) . Methods A prospect i ve cohort study was conducted at a tertiary health care center . Infection control personnel collected general and health care related data about patients . The NNIS risk index was calculated on the basis of data relating to the operation : wound contamination class , duration of surgery , and the American Society of Anesthesiologists ( ASA ) score . Results A total of 5109 surgical procedures were included in the study . The overall cumulative incidence rate was 6.3 % . The incidence of SSIs was 2.3 % ( 63.5 % of operative procedures ) , 8.3 % ( 29.7 % ) , 34.6 % ( 6.2 % ) , and 43.3 % ( 0.6 % ) , in patients with 0 , 1 , 2 , and 3 risk index , respectively . The length of hospital stay ( OR : 1.0 ; 95 % CI : 1.053–1.075 ) , preoperative length of stay ( odds ratio [ OR ] : 1.9 ; 95 % confidence interval [ CI ] : 1.953–1.981 ) , antibiotic prophylaxis ( OR : 2.5 ; 95 % CI : 1.421–4.628 ) , drainage ( OR : 1.7 ; 95 % CI : 1.360–2.353 ) , ASA score ( OR : 1.5 ; 95 % CI : 1.235–1.946 ) , class of wound contamination ( OR : 2.0 ; 95 % CI : 1.745–2.003 ) , and NNIS risk index ( OR : 1.3 ; 95 % CI : 1.063–1.7 ) were independently associated with an increased risk for SSIs . Staphylococcus aureus was the most frequently isolated microorganism , 64 % of them being methicillin-resistant . Conclusion The aim of this study was to investigate the most important risk factors associated with the development of surgical site infections ( SSIs ) . Therefore , greater attention has been given to adherence to recommendations for the prevention and control of SSIs as well as to antibiotic prophylaxis protocol OBJECTIVE To identify risk factors associated with surgical-site infection according to the depth of infection , the cardiac procedure , and the National Nosocomial Infections Surveillance System risk index . DESIGN Prospect i ve survey conducted during a 12-month period . SETTING A 48-bed cardiac surgical department in a teaching hospital . PATIENTS Patients admitted for cardiac surgery between February 2002 and January 2003 . RESULTS Surgical-site infections were diagnosed in 3 % of the patients ( 38 of 1,268 ) . Of the 38 surgical-site infections , 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6 % and 1.4 % , respectively . Cultures were positive in 28 cases and the most commonly isolated pathogen was Staphylococcus . A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection ( relative risk , 2.4 ; P < .004 ) . Heart transplantation , mechanical circulatory assistance , coronary artery bypass graft with the use of internal mammary artery , and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection . CONCLUSIONS Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts . Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis . Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection , and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection OBJECT The purpose of this study was to determine the incidence rate and risk factors of surgical site infections ( SSIs ) in neurosurgery for any type of surgery and any American Society of Anesthesiologists class . METHODS The authors undertook an exhaustive 18-month prospect i ve survey including patients who underwent neurosurgery .  In particular , a 30-day follow-up was completed in patients whose surgery did not involve placement of a prosthesis or implant , and 1-year follow-up was completed for patients who underwent surgery to place a prosthesis or implant . The Centers for Disease Control definition of SSI was used . Univariate and multivariate analyses were conducted ; all dependent variables found in univariate analysis were entered in the multiple regression model . A stepwise multiple logistic regression method was used . RESULTS Of the 844 patients studied , 35 SSIs were diagnosed , yielding an incidence rate of 4.1 % ( 95 % confidence interval 3.6 - 4.5 ) . Independent predictive risk factors for infection were cerebrospinal fluid leakage , external shunt , Altemeier class , and further neurosurgery . A lack of antibiotic prophylaxis was not found to be a risk factor . CONCLUSIONS Infection risk factors occur mainly during the postoperative period Background Although nasal carriage of MRSA has been identified as one of the risk factors for surgical site infection ( SSI ) with MRSA , there have been no reports of this in the orthopedics field . Methods This prospect i ve observational cohort study included 2,423 consecutive patients who were admitted to our department over 26 months and who underwent orthopedic surgery .  We examined the relationship between pre-existing nasal MRSA and subsequent occurrence of SSI with MRSA . Results 63 patients ( 2.6 % ) had a positive nasal MRSA culture . 15 patients ( 0.6 % ) developed SSI with MRSA . The occurrence of SSI with MRSA in nasal MRSA carriers was significantly higher than that in non-carriers ( 4 out of 63 ( 6.3 % ) vs. 11 out of 2,360 ( 0.5 % ) ; p < 0.001 ) ( adjusted OR : 11 ; 95 % CI : 3–37 ; p = 0.001 ) . Interpretation We recommend appropriate treatment of patients who are nasal carriers of MRSA before orthopedic surgery Background Surgical site infection ( SSI ) continues to be a major source of morbidity and mortality in developing countries despite recent advances in aseptic techniques . There is no baseline information regarding SSI in our setting therefore it was necessary to conduct this study to establish the prevalence , pattern and predictors of surgical site infection at Bug and o Medical Centre Mwanza ( BMC ) , Tanzania . Methods This was a cross-sectional prospect i ve study involving all patients who underwent major surgery in surgical wards between July 2009 and March 2010 . After informed written consent for the study and HIV testing , all patients who met inclusion criteria were consecutively enrolled into the study . Pre-operative , intra-operative and post operative data were collected using st and ardized data collection form . Wound specimens were collected and processed as per st and ard operative procedures ; and susceptibility testing was done using disc diffusion technique . Data were analyzed using SPSS software version 15 and STATA . Results Surgical site infection ( SSI ) was detected in 65 ( 26.0 % ) patients , of whom 56 ( 86.2 % ) and 9 ( 13.8 % ) had superficial and deep SSI respectively . Among 65 patients with clinical SSI  , 56(86.2 % ) had positive aerobic culture . Staphylococcus aureus was the predominant organism 16/56 ( 28.6 % ) ; of which 3/16 ( 18.8 % ) were MRSA . This was followed by Escherichia coli 14/56 ( 25 % ) and Klebsiella pneumoniae 10/56 ( 17.9 % ) . Among the Escherichia coli and Klebsiella pneumoniae isolates 9(64.3 % ) and 8(80 % ) were ESBL producers respectively . A total of 37/250 ( 14.8 % ) patients were HIV positive with a mean CD4 count of 296 cells/ml . Using multivariate logistic regression analysis , presence of pre-morbid illness ( OR = 6.1 ) , use of drain ( OR = 15.3 ) , use of iodine alone in skin preparation ( OR = 17.6 ) , duration of operation ≥ 3 hours ( OR = 3.2 ) and cigarette smoking ( OR = 9.6 ) significantly predicted surgical site infection ( SSI ) ConclusionS SI is common among patients admitted in surgical wards at BMC and pre-morbid illness , use of drain , iodine alone in skin preparation , prolonged duration of the operation and cigarette smoking were found to predict SSI . Prevention strategies focusing on factors associated with SSI is necessary in order to reduce the rate of SSI in our setting Background Sternal wound infection ( SWI ) is an uncommon but potentially life-threatening complication of cardiac surgery . Predisposing factors for SWI are multiple with varied frequencies in different studies . The purpose of this study was to assess the incidence , risk factors , and mortality of SWI after  coronary artery bypass grafting ( CABG ) at Tehran Heart Center . Methods This study prospect ively evaluated multiple 
    Output:
    