Journal of Hospital Infection最新文献

Background: Non-ventilator-associated pneumonia (NV-HAP), a subset of healthcare-associated pneumonia (HAP), is common and significantly increases patient mortality and hospital stay. However, no systematic review has been undertaken to synthesise the impact of NV-HAP on these outcomes.

Aim: To undertake a review of the evidence on the impact of NV-HAP on mortality and additional length of stay in adults admitted to an acute care hospital.

Methods: We performed a systematic search to identify research exploring and evaluating the impact of NV-HAP on mortality and additional length of stay in adults admitted to an acute care hospital. The electronic databases MEDLINE and CINAHL were searched, for peer-reviewed articles published between January 2004 and August 2025. An assessment of the study quality and risk of bias of included articles was conducted using the ROBINS-E and ROBINS-I tool.

Findings: 6324 studies were initially identified with 49 articles included in the review following the screening and full-text review. Twenty-six papers identified both mortality and additional length of stay results, 21 papers identified mortality results only and two papers reported additional length of stay results only. Inpatient mortality following NV-HAP ranged from 3.1 - 73.9%. Additional length of stay associated with NV-HAP was extended between 10 - 47.5 days.

Conclusions: This systematic review highlights the impact of NV-HAP on patients admitted to hospital. NV-HAP was associated with patient mortality and additional length of stay. Results of this study will inform a larger planned program of research.

Background: Surgical site infections (SSIs) are a significant cause of morbidity and mortality among healthcare-associated infections, as well as increased economic and environmental costs.

Aim: This study aimed to determine the environmental impacts of surgical site infections and the resulting carbon footprint.

Methods: This descriptive study was conducted with the participation of 553 patients who underwent surgery at a university and a city hospital in Central Anatolia between March and June 2025. Data were collected using a sociodemographic information form, the Surgical Wound Assessment Form based on the criteria of the European Center for Disease Prevention and Control, and the Carbon Footprint Calculation Tool based on the calculation tool of the Sustainable Healthcare Coalition.

Findings: A total of 91 individuals (16,5%) experienced SSIs. The total carbon footprint during the follow-up and treatment period of 91 patients with surgical site infection was calculated as approximately 1,735 kg CO₂ equivalent. The largest source of emissions was hospitalizations (clinic and intensive care: 1,133 kg CO₂e), which accounted for over 70% of the total. This was followed by patient transport (142.4 kg CO₂e) and magnetic resonance (MRI) imaging (108.0 kg CO₂e). It was determined that the development of SSIs imposes a carbon burden of 16.8 kg CO₂e per patient on average compared to a standard surgical procedure.

Conclusions: This study has quantitatively demonstrated that SSIs have a measurable and significant environmental burden in addition to their known clinical and economic burden. Preventing SSIs is a critical strategy for ensuring both patient safety and economic and ecological sustainability in surgery.

Background: Interpretation of microbial tolerance and resistance to disinfectants has long been inconsistent, with heterogeneous definitions and no clinically meaningful threshold. We propose the concept of Replication Capacity After Use (RCAU) as a practical endpoint to assess whether microbial survival after disinfectant exposure constitutes a clinically relevant phenomenon under recommended use conditions. RCAU is defined as the ability of microorganisms to replicate after exposure at recommended application concentration and exposure time. A critical RCAU corresponds to failure of a standardised quantitative suspension test.

Methods: We reassessed published evidence across the most common disinfectant substances listed by the German Association for Applied Hygiene (VAH). Reported findings on survival, tolerance and resistance were re-evaluated against the RCAU definition, with particular attention to whether testing was performed using quantitative suspension methods at application concentration.

Results: No disinfectant group has demonstrated a critical RCAU under application conditions in standardised suspension testing. Reports of reduced susceptibility or microbial survival exist, but many were not based on suspension tests at use concentrations, making interpretation with respect to RCAU uncertain. Transient or reversible adaptations have been described, yet without evidence of a critical RCAU. Only triclosan and silver compounds show established resistance mechanisms, though even here no critical RCAU has been confirmed under standardised testing.

Conclusions: RCAU provides a transparent, use-condition-anchored framework to differentiate non-critical survival from clinically relevant resistance development. Applied across disinfectant classes, it shows that no critical failures have occurred at use concentrations, although many reported findings were not assessed by standardised suspension tests.

Unexpected positive cultures - UPCs during revision of orthopaedic implants in presumed aseptic revision surgeries represent a significant clinical challenge; indeed, it is very complex to state whether a positive culture indicates a true infection or merely sample contaminations. Across hip, knee, shoulder, elbow, and spine procedures, UPC incidence remains clinically relevant, ranging from ∼7% in elbow to ∼28% in spine revisions. The organisms most often isolated, primarily Coagulase-Negative Staphylococci (23-52%) and Cutibacterium acnes (24-65%), are classic low-virulence pathogens with high contamination potential, reinforcing the uncertainty that accompanies their detection. Although published outcomes vary, most studies suggest that a single UPC rarely compromises implant survivorship, supporting the interpretation that many isolated findings represent contamination rather than infection. In contrast, multiple cultures positive for the same organism more strongly indicate occult infection, as highlighted by the ICM 2023 guidelines, which associate concordant multiculture positivity with a higher risk of re-revision or failure. Consequently, the emerging clinical consensus is that single low-virulence UPCs can often be observed, whereas multiple concordant UPCs warrant management as true infection, guiding decisions regarding antimicrobial therapy and postoperative surveillance. Given the persistent variability in published management strategies, further study is needed to standardize responses to UPCs. Finally, rapid, cost-effective intraoperative diagnostics may ultimately improve real-time infection detection and reduce uncertainty in orthopaedic implants revision.

Background: Hospital wastewater (HWW) serves as a critical reservoir for antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), especially those conferring resistance to quinolones, fluoroquinolones, and macrolides. This study investigated the prevalence and seasonal dynamics of ARB and ARGs in HWW from Kathmandu Valley, Nepal.

Methods: We collected and analyzed 16 untreated HWW samples from eight hospitals during summer and winter seasons (2022-2023). Physicochemical parameters, prevalence of ARB, selected ARGs (qnrS, aac(6')-Ib-cr, erm(B)), and class 1 integron (intI1) were assessed. Results were compared by hospital type and season.

Results: Significant seasonal differences were observed in temperature (p = 0.00024) and total suspended solids (p = 0.042). Klebsiella pneumoniae (31.67%) and Escherichia coli (28.33%) were the most frequently isolated ARB. K. pneumoniae exhibited very high resistance to ciprofloxacin (97.74%) and levofloxacin (89.47%). Among the targeted genes, the aac(6')-Ib-cr gene was the most prevalent (55.67%), followed by intI1 (50%), qnrS (25%), and erm(B) (11.67%). The erm(B) gene was significantly more prevalent in medium-sized hospitals (p = 0.001). No significant seasonal variation was observed for ARGs or the mobile genetic elements (MGEs) (p > 0.05). Although not statistically significant, strong correlations were observed between qnrS prevalence and pH (ρ = 0.912) and ammonia (ρ = 0.812), suggesting potential environmental influences on the dissemination of resistance.

Conclusions: HWW is a significant AMR reservoir, emphasizing improved wastewater treatment and antibiotic stewardship to mitigate resistance dissemination.

Background: Healthcare-associated infections are a major concern in intensive care units (ICUs), where early detection of transmission cluster is critical. Whole-genome sequencing (WGS) remains the reference method for outbreak investigation but is limited by cost and turnaround time. The IR Biotyper (IRBT) provides rapid phenotypic clustering, but its core-genome level performance remains insufficiently evaluated.

Aim: This study evaluated the analytical performance of IRBT at the core-genome level for detecting clinically relevant Gram-negative bacterial cross-transmission in ICUs.

Methods: In this prospective single-centre study, all clinical, screening, and environmental isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae complex, and Stenotrophomonas maltophilia recovered in a 36-bed ICU over seven months were analysed. Transmission cluster were assessed using core-genome Multilocus Sequence Typing (cgMLST). IRBT spectral distances were compared with allelic distances from cgMLST. Diagnostic performance metrics were calculated using both manufacturer-recommended (Bruker) and automated IRBT thresholds.

Findings: Among 283 isolates from 135 patients, cgMLST identified 23 transmission cluster events. Using Bruker thresholds, IRBT achieved high species-specific specificity (ranging from 0.91 to 0.99) and negative predictive values (≥0.94) across all species. E. cloacae complex showed near-perfect performance (sensitivity 0.94, specificity 0.99, NPV 0.998), while K. pneumoniae and E. coli demonstrated strong concordance (sensitivity ≥0.81). Lower sensitivity was observed for P. aeruginosa (0.77) and S. maltophilia (0.70). Automated thresholds improved specificity and PPV but reduced sensitivity. ROC curves confirmed high discriminatory power (AUC 0.899-0.999).

Conclusions: IRBT provides rapid, species-specific phenotypic clustering for ICU GNB transmission cluster surveillance.

Background: Piperacillin-tazobactam (TZP) is widely used empirically in Danish hospitals despite guideline restrictions, making it an important target for antimicrobial stewardship (AMS).

Aim: To evaluate the impact of a multidisciplinary antimicrobial stewardship (AMS) programme on TZP use, prescribing quality, and clinical safety outcomes at a Danish university hospital.

Methods: A prospective, quasi-experimental study using interrupted time series (ITS) and two hospital-wide point prevalence surveys (PPS, 2021 and 2023) was conducted from January 2022 to December 2024. The AMS programme, introduced in January 2023, included prospective audit and feedback, education, and monthly department-level reports. Days of therapy (DOT)/1,000 bed-days assessed antimicrobial trends. Logistic regression analysed guideline adherence and prescribing quality indicators; Poisson regression assessed changes in proportional DOT.

Results: Among 156,035 admissions, 92,346 (59.2%) occurred in AMS-implementing departments. TZP use decreased by 19.5% (95% CI: -25.5 to -13.5%; p<0.001) but increased by 26.7% in non-AMS departments (95% CI: 18.6 to 34.9%; p<0.001). Benzylpenicillin, ampicillin, and aminoglycoside use increased by 14.2%, 20.2%, and 36.4%, respectively, in AMS wards. PPS findings (n=262) showed improved guideline adherence (OR 2.32, 95% CI: 1.38-3.90), documentation of indication (OR 3.06), treatment planning (OR 9.83), and reassessment within 72 hours (OR 2.52). Thirty-day readmission decreased from 11.6% to 10.2% (p=0.0001), while in-hospital mortality remained unchanged (6.0% vs. 6.1%; p=0.962).

Conclusion: A multidisciplinary AMS programme was associated with reduced TZP use and improved prescribing quality in participating departments without adverse effects on safety indicators. These findings support AMS as an effective strategy to optimise antibiotic use.