BackgroundAssessing 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 methodsThis 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.ResultsHAIs 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.ConclusionHAIs, 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.

This study highlights the major role of treatment and duration of treatment with β-lactam/β-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.

The role of antibiotics in the epidemiology of vancomycin-resistant Enterococcus (VRE) has been studied extensively, but controversies remain as to which, and to what extent, antibiotics facilitate the emergence and dissemination of VRE in hospitals. Aggregate data on the use of several antibiotic classes in terms of defined daily doses (DDD) per 100 patient-days (PD), and VRE incidence rates in terms of clinical isolates per 1000 PD, were evaluated during a 7-year period at a tertiary-care hospital. Time-series analysis (autoregressive integrated moving average (ARIMA) and transfer function models) was used to quantify the temporal effect of antibiotic use on VRE incidence and estimate effect-delays. The incidence rate of VRE observed in a specific bimester was found to be a function of its value during the preceding bimester and of prior changes in the volume of use of four antibiotic classes. In particular, an increase of one DDD/100 PD in the use of glycopeptides, fluoroquinolones, extended-spectrum cephalosporins and beta-lactam-beta-lactamase inhibitor combinations resulted, independently, in average changes of +0.024, +0.015, + 0.020 and -0.010 isolates per 1000 PD in the incidence of VRE, with average delays of 2, 4, 2 and 6 months, respectively, which explained 56% of the observed variation in VRE rates over time. Efforts to reduce VRE cross-transmission should be supplemented by targeted antibiotic control policies. The use of glycopeptides, broad-spectrum cephalosporins and fluoroquinolones in high amounts should be the targets of such policies. Penicillin-beta-lactamase inhibitor combinations might be suitable substitutes for extended-spectrum cephalosporins.

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.

In comparison to international benchmarks, the markedly high rate of CL-BSI, the high rate of VAP and the resistance patterns of major infecting pathogens identified in this study emphasize the need to improve current practices for appropriate use and management of invasive devices in Cypriot ICUs.