The Path of More Resistance: A Comparison of NHSN and CLSI Criteria in Developing Cumulative Antimicrobial Susceptibility Test Reports and Institutional Antibiograms

Background In the absence of antimicrobial susceptibility data, the institutional antibiogram is a valuable tool to guide clinicians in the empiric treatment of infections. However, there is a misunderstanding on how best to prepare cumulative antimicrobial susceptibility testing reports (CASTRs) to guide empiric therapy (e.g., routine antibiogram) versus monitoring antimicrobial resistance, with the former following guidance from the Clinical Laboratory Standards Institute (CLSI), and the latter from Center for Disease Control and Preventions National Healthcare Safety Network (NHSN). These criteria vary markedly in their exclusion or inclusion of isolates cultured repeatedly from the same patient. Methods We compared rates of non-susceptibility (NS)using annual data from a large teaching healthcare system subset to isolates eligible by either NHSN criteria or CLSI criteria. Results For a panel of the three most prevalent gram-negative pathogens in combination with clinically relevant antimicrobial agents (or priority pathogen-agent combinations, PPACs), we found that the inclusion of duplicate isolates by NHSN criteria yielded higher NS rates than when CLSI criteria (for which duplicate isolates are not included) were applied. Conclusions Patients with duplicate isolates may not be representative of antimicrobial resistance within a population. For this reason, users of CASTR data should carefully consider that the criteria used to generate these reports can impact resulting NS rates, and therefore maintain the distinction between CASTRs created for different purposes.

Increased Rates of Secondary Bacterial Infections, Including Enterococcus Bacteremia, in Patients Hospitalized with COVID-19

Objective: We aimed to compare rates of hospital-onset secondary bacterial infections in patients with COVID-19 with rates in patients with influenza and controls, and to investigate reports of increased incidence of Enterococcus infections in patients with COVID-19. Design: Retrospective cohort study Setting: An academic quaternary care hospital in San Francisco, California Patients: Patients admitted between 10/1/2019 and 10/1/2020 with a positive SARS-CoV-2 PCR (N=314) or influenza PCR (N=82) within 2 weeks of admission were compared with inpatients without positive SARS-CoV-2 or influenza tests during the study period (N=14,332). Methods: National Healthcare Safety Network definitions were used to identify infection-related ventilator-associated complications (IVAC), probable ventilator-associated pneumonia (PVAP), bloodstream infections (BSI), and catheter-associated urinary tract infections (CAUTI). A multiple logistic regression model was used to control for likely confounders. Results: COVID-19 patients had significantly higher rates of IVAC and PVAP compared to controls, with adjusted odds ratios of 4.7 (1.7-13.9) and 10.4 (2.1-52.1), respectively. COVID-19 patients had higher incidence of BSI due to Enterococcus but not BSI generally, and whole genome sequencing of Enterococcus isolates demonstrated that nosocomial transmission did not explain the increased rate. Sub-analyses of patients admitted to the ICU and patients who required mechanical ventilation revealed similar findings. Conclusions: COVID-19 is associated with an increased risk of IVAC, PVAP and Enterococcus BSI compared with hospitalized controls, not fully explained by factors such as immunosuppressive treatments and duration of mechanical ventilation. The mechanism underlying increased rates of Enterococcus BSI in COVID-19 patients requires further investigation.

The impact of coronavirus disease 2019 (COVID-19) on healthcare-associated infections in 2020: A summary of data reported to the National Healthcare Safety Network

Objectives: To determine the impact of the coronavirus disease 2019 (COVID-19) pandemic on healthcare-associated infection (HAI) incidence in US hospitals, national- and state-level standardized infection ratios (SIRs) were calculated for each quarter in 2020 and compared to those from 2019. Methods: Central–line–associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated events (VAEs), select surgical site infections, and Clostridioides difficile and methicillin-resistant Staphylococcus aureus (MRSA) bacteremia laboratory-identified events reported to the National Healthcare Safety Network for 2019 and 2020 by acute-care hospitals were analyzed. SIRs were calculated for each HAI and quarter by dividing the number of reported infections by the number of predicted infections, calculated using 2015 national baseline data. Percentage changes between 2019 and 2020 SIRs were calculated. Supporting analyses, such as an assessment of device utilization in 2020 compared to 2019, were also performed. Results: Significant increases in the national SIRs for CLABSI, CAUTI, VAE, and MRSA bacteremia were observed in 2020. Changes in the SIR varied by quarter and state. The largest increase was observed for CLABSI, and significant increases in VAE incidence and ventilator utilization were seen across all 4 quarters of 2020. Conclusions: This report provides a national view of the increases in HAI incidence in 2020. These data highlight the need to return to conventional infection prevention and control practices and build resiliency in these programs to withstand future pandemics.

Reductions in positive Clostridioides difficile events reportable to National Healthcare Safety Network (NHSN) with adoption of reflex enzyme immunoassay (EIA) testing in 13 Atlanta hospitals

In total, 13 facilities changed C. difficile testing to reflexive testing by enzyme immunoassay (EIA) only after a positive nucleic acid-amplification test (NAAT); the standardized infection ratio (SIR) decreased by 46% (range, −12% to −71% per hospital). Changing testing practice greatly influenced a performance metric without changing C. difficile infection prevention practice.

Hospital Capacities and Shortages of Healthcare Resources Among U.S. Hospitals During COVID-19 Pandemic, National Healthcare Safety Network, March 27–July 14, 2020

During March 27–July 14, 2020, the CDC’s National Healthcare Safety Network extended its surveillance to hospital capacities responding to COVID-19 pandemic. The data showed wide variations across hospitals in case burden, bed occupancies, ventilator usage, and healthcare personnel and supply status. These data were used to inform emergency responses.

Changes in the Number of Intensive Care Unit Beds in U.S. Hospitals During the Early Months of the COVID-19 Pandemic, as reported to the National Healthcare Safety Network’s COVID-19 Module

Using data from the National Healthcare Safety Network (NHSN), we assessed changes to intensive care unit (ICU) bed capacity during the early months of the COVID-19 pandemic. Changes in capacity varied by hospital type and size. ICU beds increased by 36%, highlighting the pressure placed on hospitals during the pandemic.

Implementation of core elements of antibiotic stewardship in nursing homes—National Healthcare Safety Network, 2016–2018

Objective: To assess the national uptake of the Centers for Disease Control and Prevention’s (CDC) core elements of antibiotic stewardship in nursing homes from 2016 to 2018 and the effect of infection prevention and control (IPC) hours on the implementation of the core elements. Design: Retrospective, repeated cross-sectional analysis. Setting: US nursing homes. Methods: We used the National Healthcare Safety Network (NHSN) Long-Term Care Facility Component annual surveys from 2016 to 2018 to assess nursing home characteristics and percent implementation of the core elements. We used log-binomial regression models to estimate the association between weekly IPC hours and the implementation of all 7 core elements while controlling for confounding by facility characteristics. Results: We included 7,506 surveys from 2016 to 2018. In 2018, 71% of nursing homes reported implementation of all 7 core elements, a 28% increase from 2016. The greatest increases in implementation from 2016 to 2018 were in education (19%), reporting (18%), and drug expertise (15%). In 2018, 71% of nursing homes reported pharmacist involvement in improving antibiotic use, an increase of 27% since 2016. Nursing homes that reported at least 20 hours of IPC activity per week were 14% (95% confidence interval, 7%–20%) more likely to implement all 7 core elements when controlling for facility ownership and affiliation. Conclusions: Nursing homes reported substantial progress in antibiotic stewardship implementation from 2016 to 2018. Improvements in access to drug expertise, education, and reporting antibiotic use may reflect increased stewardship awareness and resource use among nursing home providers under new regulatory requirements. Nursing home stewardship programs may benefit from increased IPC staff hours.

Surveillance of COVID-19 vaccination in US nursing homes, December 2020-April 2021

Monitoring COVID-19 vaccination coverage among nursing home (NH) residents and staff is important to ensure high coverage and guide patient-safety policies. With the termination of the federal Pharmacy Partnership for Long-Term Care Program, another source of facility-based vaccination data is needed. We compared numbers of COVID-19 vaccinations administered to NH residents and staff reported by pharmacies participating in the temporary federal Pharmacy Partnership for Long-Term Care Program with those reported by NHs participating in new COVID-19 vaccination modules of CDC's National Healthcare Safety Network (NHSN). Pearson correlation coefficients comparing the number vaccinated between the two approaches were 0.89, 0.96, and 0.97 for residents and 0.74, 0.90, and 0.90 for staff, in the weeks ending January 3, 10, and 17, respectively. Based on subsequent NHSN reporting, vaccination coverage with ≥1 vaccine dose reached 77% for residents and 50% for staff the week ending January 31 and plateaued through April 2021.