Probabilistic microsimulation to examine the cost-effectiveness of hospital admission screening strategies for carbapenemase-producing enterobacteriaceae (CPE) in the United Kingdom

Polymicrobial outbreak of carbapenemase producing Enterobacterales managed using universal admission and discharge screening and water-safe built environment

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are antimicrobial resistant (AMR) bacteria which are increasing in incidence globally. Hospitals act as powerhouses for transmission of such bacteria with some regions experiencing prolonged outbreaks and high prevalence for several years. Current screening strategies are based on admission and risk-based screening only. Growing evidence supports hospital wastewater as playing a key role in transmission. We describe how changes to the CPE screening policy at Wexham Park Hospital (WPH) identified a hospital-based outbreak which, in turn, led to identification and mitigation of risks from the hospital wastewater system.

METHODS

Enhanced CPE patient screening (using a molecular methodology) was introduced to include admission and discharge screening of all patients admitted to the hospital over a 34-week period. The wastewater drainage infrastructure was surveyed, and likely interventions identified.

FINDINGS

The screening strategy detected a polymicrobial hospital-wide CPE outbreak involving different enzymes, predominantly New Delhi metallo-β-lactamase (NDM) and OXA-48 with the hospital wastewater system acting as the reservoir. During the 34-week period of enhanced screening, 1.2% of patients screened CPE positive, of which 14% of patients developed infection. Of the 65 CPE-positive patients detected, healthcare acquisition at WPH was likely in 47 (73%) patients. Mitigations to the risk from the hospital wastewater system combined with universal admission and discharge screening produced a long-standing reduction in transmission.

CONCLUSION

Universal admission and discharge screening along with introduction of water-safe concepts are effective in improving detection of CPE outbreaks and followed by a reduction of acquisition in healthcare settings where prevalence of such bacteria is increasing.

The impact of enhanced screening for carbapenemase-producing Enterobacterales in an acute care hospital in South Korea

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) poses a significant challenge to infection control in healthcare settings. Active screening is recommended to prevent intra-hospital CPE transmission.

METHODS

CPE screening was initiated at a 660-bed hospital in South Korea in September 2018, targeting patients previously colonized/infected or admitted to outside healthcare facilities (HCFs) within 1 month. Universal intensive care unit (ICU) screening was performed at the time of admission. After a hospital-wide CPE outbreak in July-September 2019, the screening program was enhanced by extending the indications (admission to any HCF within 6 months, receipt of hemodialysis) with weekly screening of ICU patients. The initial screening method was changed from screening cultures to the Xpert Carba-R assay. The impact was assessed by comparing the CPE incidence per 1000 admissions before (phase 1, September 2018-August 2019) and after instituting the enhanced screening program (phase 2, September 2019-December 2020).

RESULTS

A total of 13,962 (2,149 and 11,813 in each phase) were screened as indicated, among 49,490 inpatients, and monthly screening compliance increased from 18.3 to 93.5%. Compared to phase 1, the incidence of screening positive patients increased from 1.2 to 2.3 per 1,000 admissions (P = 0.005) during phase 2. The incidence of newly detected CPE patients was similar (3.1 vs. 3.4, P = 0.613) between two phases, but the incidence of hospital-onset CPE patients decreased (1.9 vs. 1.1, P = 0.018). A significant decrease was observed (0.5 to 0.1, P = 0.014) in the incidence of patients who first confirmed CPE positive through clinical cultures without a preceding positive screening. Compared to phase 1, the median exposure duration and number of CPE contacts were also markedly reduced in phase 2: 10.8 days vs. 1 day (P < 0.001) and 11 contacts vs. 1 contact (P < 0.001), respectively. During phase 2, 42 additional patients were identified by extending the admission screening indications (n = 30) and weekly in-ICU screening (n = 12).

CONCLUSIONS

The enhanced screening program enabled us to identify previously unrecognized CPE patients in a rapid manner and curtailed a hospital-wide CPE outbreak. As CPE prevalence increases, risk factors for CPE colonization can broaden, and hospital prevention strategies should be tailored to the changing local CPE epidemiology.

Economic evaluations of interventions to prevent and control health-care-associated infections: a systematic review

Almost 9 million health-care-associated infections have been estimated to occur each year in European hospitals and long-term care facilities, and these lead to an increase in morbidity, mortality, bed occupancy, and duration of hospital stay. The aim of this systematic review was to review the cost-effectiveness of interventions to limit the spread of health-care-associated infections), framed by WHO infection prevention and control core components. The Embase, National Health Service Economic Evaluation Database, Database of Abstracts of Reviews of Effects, Health Technology Assessment, Cinahl, Scopus, Pediatric Economic Database Evaluation, and Global Index Medicus databases, plus grey literature were searched for studies between Jan 1, 2009, and Aug 10, 2022. Studies were included if they reported interventions including hand hygiene, personal protective equipment, national-level or facility-level infection prevention and control programmes, education and training programmes, environmental cleaning, and surveillance. The British Medical Journal checklist was used to assess the quality of economic evaluations. 67 studies were included in the review. 25 studies evaluated methicillin-resistant Staphylococcus aureus outcomes. 31 studies evaluated screening strategies. The assessed studies that met the minimum quality criteria consisted of economic models. There was some evidence that hand hygiene, environmental cleaning, surveillance, and multimodal interventions were cost-effective. There were few or no studies investigating education and training, personal protective equipment or monitoring, and evaluation of interventions. This Review provides a map of cost-effectiveness data, so that policy makers and researchers can identify the relevant data and then assess the quality and generalisability for their setting.