Prevalence, incidence burden, and clinical impact of healthcare-associated infections and antimicrobial resistance: a national prevalent cohort study in acute care hospitals in Greece.

BACKGROUND: Assessing the overall burden of healthcare-associated infections (HAIs) is challenging, but imperative in evaluating the cost-effectiveness of infection control programs. This study aimed to estimate the point prevalence and annual incidence of HAIs in Greece and assess the excess length of stay (LOS) and mortality attributable to HAIs, overall and for main infection sites and tracer antimicrobial resistance (AMR) phenotypes and pathogens. PATIENTS AND METHODS: This prevalent cohort study used a nationally representative cross-section of 8,247 inpatients in 37 acute care hospitals to record active HAIs of all types at baseline and overall LOS and in-hospital mortality up to 90 days following hospital admission. HAI incidence was estimated using prevalence-to-incidence conversion methods. Excess mortality and LOS were assessed by Cox regression and multistate models correcting for confounding and time-dependent biases. RESULTS: HAIs were encountered with daily prevalence of 9.1% (95% confidence interval [CI] 7.8%-10.6%). The estimated annual HAI incidence was 5.2% (95% CI 4.4%-5.3%), corresponding to approximately 121,000 (95% CI 103,500-123,700) affected patients each year in the country. Ninety-day mortality risk was increased by 80% in patients with HAI compared to those without HAI (adjusted hazard ratio 1.8; 95% CI 1.3-2.6). Lower respiratory tract infections, bloodstream infections, and multiple concurrent HAIs doubled the risk of death, whereas surgical site and urinary tract infections were not associated with increased mortality. AMR had significant impact on the daily risk of 90-day mortality, which was increased by 90%-110% in patients infected by carbapenem-resistant gram-negative pathogens. HAIs increased LOS for an average of 4.3 (95% CI 2.4-6.2) additional days. Mean excess LOS exceeded 20 days in infections caused by major carbapenem-resistant gram-negative pathogens. CONCLUSION: HAIs, alongside with increasing AMR, pose significant burden to the hospital system. Burden estimates obtained in this study will be valuable in future evaluations of infection prevention programs.

Antibiotic use and the risk of carbapenem-resistant extended-spectrum-{beta}-lactamase-producing Klebsiella pneumoniae infection in hospitalized patients: results of a double case-control study.

OBJECTIVES: To identify the roles of various antibiotics as risk factors for carbapenem-resistant extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae (KP) infection (ESBL-KP infection). METHODS: Data were collected over 26 months in a tertiary care university hospital with established endemicity of carbapenem-resistant ESBL-KP (ESBL-CRKP). Using a case-case-control design, patients who presented an infection caused by carbapenem-susceptible ESBL-KP (ESBL-CSKP) and patients with ESBL-CRKP infection were compared with a common control group of hospitalized patients. Effects of treatment and duration of treatment with antibiotics were examined, adjusting for major non-antibiotic risk factors and controlling for confounding effects among the antibiotics via logistic regression models. RESULTS: Ninety-six ESBL-CRKP cases, 55 ESBL-CSKP cases and 151 controls were analysed. Multivariate analysis, adjusting for major non-antibiotic risk factors, showed that the risk of ESBL-CRKP infection rose with increasing duration of prior treatment with ß-lactam/ß-lactamase inhibitor combinations [odds ratio (OR) 1.15 per day increase; P = 0.001] and revealed that increased duration of treatment with fluoroquinolones amplified the impact of exposure to carbapenems (and vice versa) on ESBL-CRKP infection risk (OR 1.02 for interaction term; P = 0.009). Duration of prior treatment with fluoroquinolones was also associated with increased risk of ESBL-CSKP infection (OR 1.07 per day increase; P = 0.028), while prior receipt of carbapenems presented a protective effect against ESBL-CSKP infection (OR 0.21; P = 0.003). CONCLUSIONS: This study highlights the major role of treatment and duration of treatment with ß-lactam/ß-lactamase inhibitor combinations and combinations of carbapenems with fluoroquinolones. Clinicians should counterweight the potential benefits of administering these antibiotics against the increased risk of ESBL-CRKP infection.

Surveillance of surgical site infections at a tertiary care hospital in Greece: incidence, risk factors, microbiology, and impact.

BACKGROUND: In this first attempt to implement a standardized surveillance system of surgical site infections (SSI) in a Greek hospital, our objective was to identify areas for improvement by comparing main epidemiologic and microbiologic features of SSI with international data. METHODS: The National Nosocomial Infections Surveillance (NNIS) system protocols were employed to prospectively collect data for patients in 8 surgical wards who underwent surgery during a 9-month period. SSI rates were benchmarked with international data using standardized infection ratios. Risk factors were evaluated by multivariate logistic regression. RESULTS: A total of 129 SSI was identified in 2420 operations (5.3%), of which 47.3% developed after discharge. SSI rates were higher for 2 of 20 operation categories compared with Spanish and Italian data and for 12 of 20 categories compared with NNIS data. Gram-positive microorganisms accounted for 52.1% of SSI isolates, and Enterococci were predominant. Alarming resistance patterns for Enterococcus faecium and Acinetobacter baumannii were recorded. Potentially modifiable risk factors for SSI included multiple procedures, extended duration of operation, and antibiotic prophylaxis. SSI was associated with prolongation of postoperative stay but not with mortality. CONCLUSION: Comparisons of surveillance data in our hospital with international benchmarks provided useful information for infection control interventions to reduce the incidence of SSI.

Case-mix adjustment approach to benchmarking prevalence rates of nosocomial infection in hospitals in Cyprus and Greece.

OBJECTIVE: To examine the effect of heterogeneous case mix for a benchmarking analysis and interhospital comparison of the prevalence rates of nosocomial infection. DESIGN: Cross-sectional survey. SETTING: Eleven hospitals located in Cyprus and in the region of Crete in Greece. METHODS: The survey included all inpatients in the medical, surgical, pediatric, and gynecology-obstetrics wards, as well as those in intensive care units. Centers for Disease Control and Prevention criteria were used to define nosocomial infection. The information collected for all patients included demographic characteristics, primary admission diagnosis, Karnofsky functional status index, Charlson comorbidity index, McCabe-Jackson severity of illness classification, use of antibiotics, and prior exposures to medical and surgical risk factors. Outcome data were also recorded for all patients. Case mix-adjusted rates were calculated by using a multivariate logistic regression model for nosocomial infection risk and an indirect standardization method.Results. The overall prevalence rate of nosocomial infection was 7.0% (95% confidence interval, 5.9%-8.3%) among 1,832 screened patients. Significant variation in nosocomial infection rates was observed across hospitals (range, 2.2%-9.6%). Logistic regression analysis indicated that the mean predicted risk of nosocomial infection across hospitals ranged from 3.7% to 10.3%, suggesting considerable variation in patient risk. Case mix-adjusted rates ranged from 2.6% to 12.4%, and the relative ranking of hospitals was affected by case-mix adjustment in 8 cases (72.8%). Nosocomial infection was significantly and independently associated with mortality (adjusted odds ratio, 3.6 [95% confidence interval, 2.1-6.1]). CONCLUSION: The first attempt to rank the risk of nosocomial infection in these regions demonstrated the importance of accounting for heterogeneous case mix before attempting interhospital comparisons.

Device-associated nosocomial infection rates in intensive care units in Greece.

Site-specific, risk-adjusted incidence rates of intensive care unit (ICU)-acquired infections were obtained through standardized surveillance in 8 ICUs in Greece. High rates were observed for central line-associated bloodstream infection (12.1 infections per 1,000 device-days) and ventilator-associated pneumonia (12.5 infections per 1,000 device-days). Gram-negative microorganisms accounted for 60.4% of the isolates recovered, and Acinetobacter species were predominant. To reduce infection rates in Greek ICUs, comprehensive infection control programs are required.

Epidemiology and molecular analysis of intestinal colonization by vancomycin-resistant enterococci in greek hospitals.

From 1,246 specimens collected from 13 Greek hospitals, 266 vancomycin-resistant enterococci strains were isolated from 255 patients (20.5%). The VanA phenotype was present in 82 (30.8%) strains, the VanB phenotype in 17 (6.4%) strains, the VanC1 phenotype in 152 (57.1%) strains, and the VanC2/C3 phenotypes in 15 (5.6%) strains. When only VanA and VanB phenotypes were considered, the overall prevalence was 7.5%. Eighty-six isolates exhibiting the VanA or VanB phenotype were analyzed by pulsed-field gel electrophoresis (PFGE), and 46 PFGE groups were found.

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.