Risk control of surgical site infection after cardiothoracic surgery

The purpose of this prospective study was to investigate whether a risk control programme based on risk assessment, new treatment modalities and the presence of a surveillance programme reduces the incidence of surgical site infections (SSI). Between January 2001 and December 2003, 167 patients were treated for a total of 183 SSIs. Data were collected on pre-operative risk factors, intra-operative data and postoperative recovery, including complications, infecting organisms, SSI treatment techniques and length of hospital stay. In this series, the total incidence of SSI was 5.6%. The mean age of affected patients was 65.1 years with a range of 20–87 years. Mean intensive care and hospital stay for SSI was 3.6 days and 18.8 days, respectively. Total mortality was 4.8%. Many risk factors were encountered, some of which were associated with a high morbidity. The majority of SSIs were treated by topical negative pressure therapy (N=81), which gave few side-effects and good clinical results. After starting the surveillance programme, a steady decline in prevalence was observed from 8.9% to 3.9%. This series adds to the evidence that SSI after cardiothoracic surgery is a major but mainly preventable cause of morbidity and mortality. Risk factor assessment, application of novel treatment modalities and an adequate surveillance system all increased patient safety.     

Health and economic impact of surgical site infections diagnosed after hospital discharge

Although surgical site infections (SSIs) are known to cause substantial illness and costs during the index hospitalization, little information exists about the impact of infections diagnosed after discharge, which constitute the majority of SSIs. In this study, using patient questionnaire and administrative databases, we assessed the clinical outcomes and resource utilization in the 8-week postoperative period associated with SSIs recognized after discharge. SSI recognized after discharge was confirmed in 89 (1.9%) of 4,571 procedures from May 1997 to October 1998. Patients with SSI, but not controls, had a significant decline in SF-12 (Medical Outcomes Study 12-Item Short-Form Health Survey) mental health component scores after surgery (p=0.004). Patients required significantly more outpatient visits, emergency room visits, radiology services, readmissions, and home health aide services than did controls. Average total costs during the 8 weeks after discharge were US dollars 5,155 for patients with SSI and US dollars 1,773 for controls (p<0.001).     

Surgical site infection after central venous catheter-related infection in cardiac surgery. Analysis of a cohort of 7557 patients

The aim of this study was to establish the relationship between the occurrence of a surgical site infection (SSI) and the presence of a central venous catheter-related infection (CVCRI). The Department of Thoracic and Cardiovascular Surgery, University Hospital, Rouen, has carried out a prospective epidemiological survey of all nosocomial infections (pneumonia, SSI and CVCRI) since 1997. The study group included all consecutive patients who underwent cardiac surgery over a 10-year period from 1997 to 2007. A nested case–control study was conducted to identify the risk factors for SSI after CVCRI. Cases were patients with SSI after CVCRI and controls were randomized from patients who presented with CVCRI not followed by SSI. In total, 7557 patients were included and 133 SSIs (1.7%) were identified. The rate of superficial SSI was 0.7% [95% confidence interval (CI): 0.5–0.9] and of mediastinitis was 1.0% (95% CI: 0.8–1.2). Among the 133 cases of SSI, 12 (9.0%; 95% CI: 5.0–14.8) occurred after a CVCRI with identical micro-organisms. CVCRI [adjusted odds ratio (aOR): 5.2; 95% CI: 3.2–8.5], coronary artery bypass grafting (aOR: 2.9; 95% CI: 1.6–5.2), and obesity (aOR: 11.4; 95% CI: 1.0–130.1) were independent factors associated with SSI. The new finding of this study is that patients with CVCRI were 5.2 times more likely to develop SSI compared to patients without CVCRI.     

Incidence of surgical site infections and accompanying risk factors in Vietnamese orthopaedic patients

A cohort study of surgical site infections (SSIs) was conducted in 582 orthopaedic surgical patients at Cho Ray Hospital, a reference hospital in Ho Chi Minh City, Vietnam, in order to determine the incidence and analyse risk factors for SSIs in this population. The SSI incidence rate was 12.5% (73 of 582); 3.6% incisional SSIs, 6.8% deep incisional SSIs and 2.1% organ/space SSIs. The incidence increased from 2% in clean wounds to 44.6% in dirty wounds, or 1.3% in patients with a National Nosocomial Infections Surveillance (NNIS) risk index of 0 to 75% in patients with an NNIS risk ratio of 3. In multi-variate analysis, having a dirty wound [odds ratio (OR) 8.7; 95% confidence intervals (CI) 4.6--16.4], American Society of Anesthesiologists' score >2 (OR 3.9; 95%CI 1.8-8.8), procedures with external fixation (OR 2.9; 95%CI 1.4-5.9), emergency surgery with motor-vehicle-related trauma (OR 2.1; 95%CI 1.2-3.9), or duration of procedure >2h (OR 2.1; 95%CI 1.1-4.2) were independent risk factors for SSI. Lack of appropriate prophylaxis was of borderline significance (OR 3.2; 95%CI 0.9-11.1, P=0.06). Among 76 patients with SSIs, 22 patients were discovered during postdischarge follow-up. These late SSIs had age as an additional risk factor (OR 2.8; 95%CI 1.1-7.2). Our data show that SSIs were frequent and differed widely by wound class. The NNIS risk index was predictive of SSI for this population. With a high number of motor vehicle accidents in Vietnam, the majority of orthopaedic operations are trauma related. Emergency surgery for injuries sustained in these accidents, and procedures with external fixation were especially prone to infections.     

Impact of surgical site infection surveillance in a neurosurgical unit

This article describes a two-year surveillance of neurosurgical site infections and an outbreak of infections in deep brain stimulation (DBS) cases. From April to December 2008, six patients had a DBS surgical site infection (SSI). Audits of hygiene practices, infection control of the healthcare environment, and preoperative antimicrobial prophylaxis characteristics were carried out. The results of surgical audits showed that skin preparation and antimicrobial prophylaxis were not being performed adequately. In 2008, the general SSI rate was 1.8% (27 SSIs/1471 patients). Length of preoperative stay was significantly longer among infected patients (2.7 ± 2.9 months) compared with uninfected patients (2.2 ± 4.6 months) (P=0.01). Based on these results, skin preparation and antimicrobial prophylaxis were reviewed with the neurosurgery team. In 2009, the general SSI rate was reduced to 1.1% (16 SSI in 1410 patients), a reduction from 2008 (P=0.12). Although the overall incidence of SSI in 2008 (1.8%) was within the range of published data, this surveillance of SSIs permitted identification of site operative infected patients surgically treated for DBS. A set of actions was then taken to reduce SSI risk. This work demonstrates how an active surveillance programme can successfully change clinical care practice.     

Surveillance for surgical site infection after hospital discharge: a surgical procedure-specific perspective.

OBJECTIVE: To estimate the rate of surgical site infection (SSI) occurring after hospital discharge, to evaluate whether limiting surveillance to inpatients underestimates the true rate of SSI, and to select surgical procedures that should be included in a postdischarge surveillance program. DESIGN: Prospective surveillance study. SETTING: A surgical ward at a university teaching hospital in Italy. PATIENTS: A total of 264 surgical patients were included in the study. RESULTS: The global SSI rate was 10.6% (28 patients); 17 (60.2%) of patients with an SSI developed the infection after hospital discharge. The overall mean length of postoperative stay (+/-SD) for patients who acquired a postdischarge SSI was 4.9+/-3.7 days, and SSI was diagnosed a mean duration (+/-SD) of 11.5+/-4.5 days after surgery. Among procedures with postdischarge SSIs, those classified by the National Nosocomial Infections Surveillance system (NNIS) as herniorrhaphy, mastectomy, other endocrine system, and other integumentary system were associated with a mean postoperative stay that was less than the mean time between the operation and the onset of SSI. Four (36%) of in-hospital SSIs occurred after procedures with an NNIS risk index of 0, and 7 (64%) occurred after procedures with an NNIS risk index of 1 or higher. Of the 17 SSIs diagnosed after discharge, 14 procedures (82%) had an NNIS risk index of 0, compared with 3 procedures (18%) with an NNIS risk index of 1 or higher. CONCLUSIONS: Our results revealed an increased risk of postdischarge SSI after some types of surgical procedures and suggest that there is an important need to change from generalized to NNIS operative category-directed postdischarge surveillance, at least for procedures locally considered to be high-risk.     

肿瘤外科医师手术感染专率调查

目的 监测某院肿瘤外科医师手术感染专率，以督促降低手术后感染率。方法 对2000年各类肿瘤手术感染情况、相关危险因素进行监测，并通过危险指数调整，比较主刀医师手术切口感染率。结果 全年共进行各类肿瘤手术398例，医院感染率为15．83％，切口感染率为9．30％；患者健康状况(按美国麻醉学会分级标准定为一类和二类)、伤口类型及手术时间与手术后感染相关。主刀医师感染专率最高为17．02％，经危险指数调整后，最高感染专率为13．64％；危险指数增高，感染率随之升高。结论 肿瘤外科手术后感染涉及多方面因素，主要与手术操作水平及患者自身健康状况、切口类型相关，应充分重视各类危险因素，改进存在问题，降低感染率。     

Risk factors for surgical site infection in children at the teaching hospital Gabriel Touré, Bamako

A six-month prospective surveillance study of postoperative surgical site infections (SSIs) was undertaken between January and June 2010 in paediatric patients aged <15 years, in the University Hospital Gabriel Touré, Mali. SSI was documented in 43 out of 352 children (12.2%). SSIs were significantly more common after emergency operations, in patients with a National Nosocomial Infection Surveillance System (NNISS) score of 2 or 3, and in patients operated on by trainee rather than by experienced surgeons. Children with anaemia or malnutrition were significantly more likely to develop infection postoperatively. Patients' sex, duration of preoperative stay and the number of patients in the hospital room were not considered as risk factors for infection (P>0.05).     

The impact of surgical-site infections following orthopedic surgery at a community hospital and a university hospital: adverse quality of life, excess length of stay, and extra cost.

OBJECTIVE: To measure the impact of orthopedic surgical-site infections (SSIs) on quality of life, length of hospitalization, and cost. DESIGN: A pairwise-matched (1:1) case-control study within a cohort. SETTING: A tertiary-care university medical center and a community hospital. PATIENTS: Cases of orthopedic SSIs were prospectively identified by infection control professionals. Matched controls were selected from the entire cohort of patients undergoing orthopedic surgery who did not have an SSI. Matching variables included type of surgical procedure, National Nosocomial Infections Surveillance risk index, age, date of surgery, and surgeon. MAIN OUTCOME MEASURES: Quality of life, duration of postoperative hospital stay, frequency of hospital readmission, overall direct medical costs, and mortality rate. RESULTS: Fifty-nine SSIs were identified. Each orthopedic SSI accounted for a median of 1 extra day of stay during the initial hospitalization (P = .001) and a median of 14 extra days of hospitalization during the follow-up period (P = .0001). Patients with SSI required more rehospitalizations (median, 2 vs 1; P = .0001) and more total surgical procedures (median, 2 vs 1; P = .0001). The median total direct cost of hospitalizations per infected patient was $24,344, compared with $6,636 per uninfected patient (P = .0001). Mortality rates were similar for cases and controls. Quality of life was adversely affected for patients with SSI. The largest decrements in scores on the Medical Outcome Study Short Form 36 questionnaire were seen in the physical functioning and role-physical domains. CONCLUSIONS: Orthopedic SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase healthcare costs by more than 300%. Moreover, patients with orthopedic SSIs have substantially greater physical limitations and significant reductions in their health-related quality of life.     

Incidence of surgical-site infections and the validity of the National Nosocomial Infections Surveillance System risk index in a general surgical ward in Santa Cruz, Bolivia.

OBJECTIVES: To estimate the frequency of and risk factors for surgical-site infections (SSIs) in Bolivia, and to study the performance of the National Nosocomial Infections Surveillance (NNIS) System risk index in a developing country. DESIGN: A prospective study with patient follow-up until the 30th postoperative day. SETTING: A general surgical ward of a public hospital in Santa Cruz, Bolivia. PATIENTS: Patients admitted to the ward between July 1998 and June 1999 on whom surgical procedures were performed. RESULTS: Follow-up was complete for 91.5% of 376 surgical procedures. The overall SSI rate was 12%. Thirty-four (75.6%) of the 45 SSIs were culture positive. A logistic regression model retained an American Society of Anesthesiologists score of more than 1 (odds ratio [OR], 1.87), a not-clean wound class (OR, 2.28), a procedure duration of more than 1 hour (OR, 1.81), and drain (OR, 1.98) as independent risk factors for SSI. There was no significant association between the NNIS System risk index and SSI rates. However, a "local" risk index constructed with the above cutoff points showed a linear trend with SSI (P < .001) and a relative risk of 3.18 for risk class 3 versus a class of less than 3. CONCLUSIONS: SSIs cause considerable morbidity in Santa Cruz. Appropriate nosocomial infection surveillance and control should be introduced. The NNIS System risk index did not discriminate between patients at low and high risk for SSI in this hospital setting, but a risk score based on local cutoff points performed substantially better.     

Does the Centers for Disease Control's NNIS system risk index stratify patients undergoing cardiothoracic operations by their risk of surgical-site infection?

BACKGROUND: In 1991, the Centers for Disease Control and Prevention devised the National Nosocomial Infection Surveillance (NNIS) System risk index to stratify populations of surgical patients by the risk of acquiring surgical-site infections (SSIs). OBJECTIVE: To determine whether the NNIS risk index adequately stratifies a population of cardiothoracic surgery patients by the risk of developing SSI. DESIGN: Case-control study. SETTING: The University of Iowa Hospitals and Clinics, a 900-bed, midwestern, tertiary-care hospital. PATIENTS: 201 patients with SSIs identified by prospective infection control surveillance and 398 controls matched by age, gender, type of procedure, and date of procedure. All patients underwent cardiothoracic operative procedures between November 1990 and January 1994. RESULTS: The SSI rate was 7.8%. Seventy-four percent of cases and 80% of controls had a NNIS risk index score of 1; 24% of cases and 16% of controls had a score of 2 (P=.05). Patients with a NNIS risk score > or =2 were 1.8 times more likely to develop an SSI than those with a NNIS score <2 (odds ratio, 1.83; 95% confidence interval, 1.14-2.94, P=.01). The duration of the procedure was the only component of the index that stratified the population by risk of SSI. CONCLUSIONS: The risk of SSI after cardiothoracic operations increases as the NNIS risk index score increases. However, this index only dichotomized the patient population on the basis of the procedure duration. More research is needed to develop a risk index that adequately stratifies the risk of SSI after cardiothoracic operations.     

Prevalence of surgical-site infections and patterns of antimicrobial use in a large tertiary-care hospital in Ho Chi Minh City, Vietnam.

BACKGROUND: Few studies have been conducted in Vietnam on the epidemiology of healthcare-associated infections or antimicrobial use. Thus, we sought to determine the prevalence of and risk factors for surgical-site infections (SSIs) and to document antimicrobial use in surgical patients in a large healthcare facility in Vietnam. METHODS: We conducted a point-prevalence survey of SSIs and antimicrobial use at Cho Ray Hospital, Ho Chi Minh City, a 1,250-bed inpatient facility. All patients on the 11 surgical wards and 2 intensive care units who had surgery within 30 days before the survey date were included. RESULTS: Of 391 surgical patients, 56 (14.3%) had an SSI. When we compared patients with and without SSIs, factors associated with infection included trauma (relative risk [RR], 2.65; 95% confidence interval [CI95], 1.60 to 4.37; P < .001), emergency surgery (RR, 2.74; CI95, 1.65 to 4.55; P < .001), and dirty wounds (RR, 3.77; CI95, 2.39 to 5.96; P < .001). Overall, 198 (51%) of the patients received antimicrobials more than 8 hours before surgery and 390 (99.7%) received them after surgery. Commonly used antimicrobials included third-generation cephalosporins and aminoglycosides. Thirty isolates were identified from 26 SSI patient cultures; of the 25 isolates undergoing antimicrobial susceptibility testing, 22 (88%) were resistant to ceftriaxone and 24 (92%) to gentamicin. CONCLUSIONS: Our data show that (1) SSIs are prevalent at Cho Ray Hospital; (2) antimicrobial use among surgical patients is widespread and inconsistent with published guidelines; and (3) pathogens often are resistant to commonly used antimicrobials. SSI prevention interventions, including appropriate use of antimicrobials, are needed in this population.     

Pattern of Pathogens and Their Sensitivity Isolated from Surgical Site Infections at the Aga Khan University Hospital,Nairobi, Kenya

Background

In low income countries, surgical site infections (SSIs) are costly and impose a heavy and potentially preventable burden on both patients and healthcare providers. This study aimed to determine the occurrence of SSI, pathogens associated with SSI, the antibiogram of the causative pathogens and specific risk factors associated with SSI at the hospital.

Methods

Two hundred and sixty-eight respondents admitted for general surgical procedures (other than neurological and cardiothoracic surgeries) at the Aga Khan University Hospital were eligible to take part in the study. Post-surgery patients were observed for symptoms of infection. Follow ups were done through the consulting clinics, breast clinic and casualty dressing clinic by a team of surgeons. In cases of infection, pus swabs were collected for culture.

Results

SSI incidence rate was 7.0%, pathogens isolated from SSI included gram negative enteric bacilli and S. aureus which was the most prevalent bacterial isolate. Only one isolate of MRSA was found and all staphylococci were susceptible to Vancomycin. Preoperative stay ≥ 2 days and wound class were the risk factors associated with SSI.

Conclusion

The SSI incidence rates (7.0%) observed in this study were relatively lower than the ones documented in other studies in Kenya. S. aureus is the most prevalent pathogen associated with SSI. Similar to findings from other studies done in the region; prolonged hospital stay and dirty wounds were the risks associated with postsurgical sepsis at the hospital.     

Perioperative variables associated with surgical site infection in breast cancer surgery

Despite the fact that breast operations are usually categorized as clean procedures, higher surgical site infection (SSI) rates are reported. This study aimed to determine the perioperative variables related to SSI in breast cancer patients. Medical records of breast cancer patients undergoing surgery between January 2005 and August 2007 at a university based hospital were reviewed. Preoperative, intraoperative, and postoperative clinical data from 199 patients were extracted and analysed. Overall, the SSI rate was 19.1% (38 cases). SSI was associated with a high body mass index (P=0.001), history of diabetes mellitus (P<0.0001), smoking (P<0.0001), or active skin disorders (P<0.0001). Other SSI-related variables included a tumour at an advanced clinical stage (P=0.003) and neoadjuvant therapy (P=0.003). Breast-conserving operations were less frequently associated with SSI than were radical procedures (mastectomy alone and mastectomy followed by immediate reconstruction) (P=0.0001).     

Random effect modelling of patient-related risk factors in orthopaedic procedures: results from the Dutch nosocomial infection surveillance network 'PREZIES'

In the Dutch surveillance for surgical site infections (SSIs), data from 70277 orthopaedic procedures with 1895 SSIs were collected between 1996 and 2003. The aims of this study were: (1) to analyse the trends in SSIs associated with Gram-positive and Gram-negative bacteria; (2) to estimate patient-related risk factors for deep and superficial SSIs after all orthopaedic procedures, with special attention to primary total hip arthroplasty (THA); and (3) to analyse inherent differences in infection risk between hospitals. A random effect model was used to estimate the odds ratios of patient-related risk factors for developing an SSI, and to describe the distribution of the most widespread bacterial species responsible for SSIs among hospitals. Gram-positive organisms, mainly staphylococci, were the main cause of both deep (84.0%) and superficial SSIs (69.1%) after orthopaedic procedures. The percentage of SSIs after THA caused by coagulase-negative staphylococci decreased over the surveillance period, while the contribution of Staphylococcus aureus increased. Temporary elevations in the incidence of the most widespread pathogen species were observed within hospitals. Patient-related factors such as the National Nosocomial Infections Surveillance System risk index or age had little effect on the predictive power of the random effect models. This study underlines the usefulness of a random effect model, which adjusts risk estimates for random variation between hospitals, in a multicentre study on risk factors for SSIs.     

乡镇级医院手术部位感染影响因素研究

目的 研究乡镇级医院普外科手术患者手术部位感染(SSI)的影响因素及预防措施.方法 对山东省泰安市岱岳区15所乡镇医院2008年3月-2011年1月收治的外科手术患者SSI发生情况进行回顾性调查,通过病例对照研究分析SSI的影响因素.结果 共调查3105例外科术后患者,发生SSI 107例,手术部位感染率为3.45％、肠道手术感染率为18.75％和前列腺手术感染率为12.56％的SSI最为严重,多因素条件logistic回归分析筛选的影响因素有切口类型、住院时间、手术持续时间、手术性质、糖尿病、体质指数.结论 乡镇级医院SSI较严重,切口类型、住院时间、手术持续时间、手术性质、糖尿病、体质指数等多种因素与SSI发生有关.     

Caesarean section surgical site infection surveillance

Surveillance of surgical site infection (SSI) is an important infection control activity. The Caesarean section procedure was selected, as part of the Scottish Surveillance of Healthcare Associated Infection Programme, to monitor and report upon the incidence of SSI. Data were collected prospectively for 715 patients undergoing a Caesarean section procedure for 35 weeks during the latter months of 2002 and the first quarter of 2003. Of these, 80 (11.2%) patients developed an SSI, 57 (71%) of which were detected by postdischarge surveillance. Risk factors associated with infection were analysed. The choice of subcuticular suture rather than staples to close the surgical site was associated with a significantly lower incidence of infection (P=0.021). Obese women experienced significantly more infections than women with a normal body mass index (P=0.028). Dissemination of the surveillance results has made clinicians aware of the influence of body mass index and choice of skin closure in relation to SSI in this patient population. Analysis of these data has led to a review of local practice. The results also indicate the importance of postdischarge surveillance if SSIs are to be detected in this patient group. Continuous data collection and timely dissemination of the results are important factors acting as the catalyst for a review of practice.     

Morbidity and mortality associated withsurgical site infections: results from the 1997–1999 INCISO surveillance

Since 1997, a surgical-site infections (SSI) surveillance network (INCISO) has been implemented in volunteer general surgical units in Northern France. For three months each year, all patients who undergo a surgical procedure are consecutively reviewed for their peri-operative condition and traced for outcome with a 30-day follow-up. Of the 38973 surgical patients included over a three-year period, 1344 (3.4%) developed SSI and 568 died (1.5%) including 78 with an SSI. Organ-space and deep incisional SSI were associated with a higher mortality and required re-operation more frequently than did superficial incisional SSI. SSI incidence and mortality varied according to the surgical procedure. SSI was a significant predictor of mortality, independently of NNIS risk index and other survival predictors. Thirty-eight percent of deaths in SSI patients were attributable to infection. Hence, the significant impact of SSI on mortality and morbidity in surgical patients is now an additional reason to reinforce compliance of surgical staff with preventive measures and hygiene practices.     

Surgical-site infections following cesarean section in an Estonian university hospital: postdischarge surveillance and analysis of risk factors.

OBJECTIVES: To evaluate a multi-method approach to postdischarge surveillance of surgical-site infections (SSIs) and to identify infection rates and risk factors associated with SSI following cesarean section. DESIGN: Cross-sectional survey. SETTING: Academic tertiary-care obstetric and gynecology center with 54 beds. PATIENTS: All women who delivered by cesarean section in Tartu University Women's Clinic during 2002. METHODS: Infections were identified during hospital stay or by postdischarge survey using a combination of telephone calls, healthcare worker questionnaire, and outpatient medical records review. SSI was diagnosed according to the criteria of the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance System. RESULTS: The multi-method approach gave a follow-up rate of 94.8%. Of 305 patients, 19 (6.2%; 95% confidence interval [CI95], 3.8-9.6) had SSIs. Forty-two percent of these SSIs were detected during postdischarge surveillance. We found three variables associated with increased risk for developing SSI: internal fetal monitoring (odds ratio [OR], 16.6; CI95, 2.2-125.8; P = .007), chorioamnionitis (OR, 8.8; CI95, 1.1-69.6; P = .04), and surgical wound classes III and IV (OR, 3.8; CI95, 1.2-11.8; P = .02). CONCLUSIONS: The high response rate validated the effectiveness of this kind of surveillance method and was most suitable in current circumstances. A challenge exists to decrease the frequency of internal fetal monitoring and to treat chorioamnionitis as soon as possible.     

Prevalence of nosocomial infections after surgery in Greek hospitals: results of two nationwide surveys.

OBJECTIVE: To determine the frequency and type of nosocomial infections (NIs) (especially surgical-site infections [SSIs]), risk factors, and the type and duration of antibiotic use among surgical patients in Greek hospitals. DESIGN: Two point-prevalence studies. SETTING: Fourteen Greek hospitals. PATIENTS: Those in the hospitals during two prevalence surveys undergoing surgery during their stay. RESULTS: In the 1999 survey, 129 of 1,037 surgical patients had developed 148 NIs (14.3%). A total of 1,093 operations were registered, and 49 SSIs (4.5%) were found. In the 2000 survey, 82 of 868 surgical patients had developed 88 NIs (10.1%). A total of 902 operations were registered, and 38 SSIs were detected (4.2%). The median length of stay (LOS) for surgical patients without SSI was 10.0 days (range, 1-19 days); for patients who developed SSI it was 30 days (range, 1-52 days; P < .001). The median LOS prior to surgery for patients without SSI was 1 day (range, 0-4 days); for patients who developed SSI it was 3 days (range, 0-7.5 days; P < .001). Among 30 possible risk factors studied, wound class, LOS prior to surgery, and central venous catheterization were independent predictors of SSI. Median durations of prophylactic antibiotic therapy were 4 days (range, 1-14 days) and 6 days (range, 1-16 days) in the 1999 and 2000 surveys, respectively. CONCLUSION: Surgical patients in Greek hospitals suffered higher rates of SSI than did surgical patients in other developed countries while prophylactic antibiotics were used excessively.