Asymptomatic Testing of Hospital Admissions for SARS-CoV-2: Is it OK to Stop?

Universal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing of all persons admitted to acute care hospitals has become common practice. We describe why 1 hospital discontinued this practice after weighing potential benefits against known harms. Considerations around the benefits shifted as we saw a decline in SARS-CoV-2 community transmission and coronavirus disease 2019 (COVID-19) severity of illness, increased availability of vaccines and treatments, and better understood the many other transmission pathways in the healthcare environment. Considerations around harms included the additional strain on laboratory and infection prevention resources, and several unintended adverse consequences of admission screening for patients, including unnecessary isolation, antiviral treatments, and delays in care delivery. Poor test performance for detection of infectiousness also played a significant role in determining to stop universal screening. No increase in hospital-onset COVID-19 has been documented since discontinuation of admission testing. We continue to apply other established layers of prevention while monitoring for any change in incidence of within-facility transmission of SARS-CoV-2.

Are contact precautions "essential" for the prevention of healthcare-associated methicillin-resistant Staphylococcus aureus?

The recently updated SHEA/IDSA/APIC practice recommendations for MRSA prevention in acute care facilities list contact precautions (CP) for patients known to be infected or colonized with MRSA as an "essential practice", meaning that it should be adopted in all acute care facilities. We argue that existing evidence on benefits and harms associated with CP do not justify this recommendation. There are no controlled trials that support broad use of CP for MRSA prevention. Data from hospitals that have discontinued CP for MRSA have found no impact on MRSA acquisition or infection. The burden and harms of CP remain concerning, including the environmental impact of increased gown and glove use. We suggest that CP be included among other "additional approaches" to MRSA prevention that can be implemented under specific circumstances (e.g. outbreaks, evidence of ongoing transmission despite application of essential practices).

Pandemic Demand for SARS-CoV-2 Testing Led to Critical Supply and Workforce Shortages in U.S. Clinical and Public Health Laboratories.

COVID-19 has brought unprecedented challenges to clinical and public health laboratories. While U.S. laboratories have continued striving to provide quality test results during the pandemic, the uncertainty and lack of supplies became a significant hurdle, hindering day-to-day laboratory operations and the ability to increase testing capacity for both SARS-CoV-2 and non-COVID-19 testing. In addition, long-standing laboratory workforce shortages became apparent, hindering the ability of clinical and public health laboratories to rapidly increase testing. The American Society for Microbiology, the College of American Pathologists, the National Coalition of STD Directors, and the Emerging Infections Network independently conducted surveys in 2020 and early 2021 to assess the capacity of the nation's clinical laboratories to respond to the increase in demand for testing during the COVID-19 pandemic. The results of these surveys highlighted the shortages of crucial supplies for SARS-CoV-2 testing and supplies for other routine laboratory diagnostics, as well as a shortage of trained personnel to perform testing. The conclusions are based on communications, observations, and the survey results of the clinical laboratory, public health, and professional organizations represented here. While the results of each survey considered separately may not be representative of the entire community, when considered together they provide remarkably similar results, further validating the findings and highlighting the importance of laboratory supply chains and the personnel capable of performing these tests for any response to a large-scale public health emergency.

What Is New in Fungal Infections?

Invasive fungal infections are an increasingly important cause of morbidity and mortality. We provide a summary of important changes in the epidemiology of invasive fungal infections, citing examples of new emerging pathogens, expanding populations who are at-risk, and increasing antifungal resistance. We review how human activity and climate change may play a role in some of these changes. Finally, we discuss how these changes create the need for advances in fungal diagnostics. The limitations of existing fungal diagnostic testing emphasize the critically important role of histopathology in the early recognition of fungal disease.

Days of Antibiotic Spectrum Coverage: A Novel Metric for Inpatient Antibiotic Consumption.

BACKGROUND: Days of therapy (DOT), the most widely used benchmarking metric for antibiotic consumption, may not fully measure stewardship efforts to promote use of narrow-spectrum agents and may inadvertently discourage the use of combination regimens when single-agent alternatives have greater adverse effects. To overcome the limitations of DOT, we developed a novel metric, days of antibiotic spectrum coverage (DASC), and compared hospital performances using this novel metric with DOT. METHODS: We evaluated 77 antibiotics in 16 categories of antibacterial activity to develop our spectrum scoring system. DASC was then calculated as cumulative daily antibiotic spectrum coverage (ASC) scores. To compare hospital benchmarking using DOT and DASC, we conducted a retrospective cohort study of adult patients admitted to acute care units within the Veterans Health Administration system in 2018. Antibiotic administration data were aggregated to calculate each hospital's DOT and DASC per 1000 days present (DP) for ranking. RESULTS: The ASC score for each antibiotic ranged from 2 to 15. There was little correlation between DOT per 1000 DP and DASC per DOT, indicating that lower antibiotic consumption at a hospital does not necessarily mean more frequent use of narrow-spectrum antibiotics. The differences in each hospital's ranking between DOT and DASC per 1000 DP ranged from -29.0% to 25.0%, respectively, with 27 hospitals (21.8%) having differences >10%. CONCLUSIONS: We propose a novel composite metric for antibiotic stewardship, DASC, that combines consumption and spectrum as a potential replacement for DOT. Further studies are needed to evaluate whether benchmarking using the DASC will improve evaluations of stewardship.

Advancing Diagnostic Stewardship for Healthcare-Associated Infections, Antibiotic Resistance, and Sepsis.

Diagnostic stewardship means ordering the right tests for the right patient at the right time to inform optimal clinical care. Diagnostic stewardship is an integral part of antibiotic stewardship efforts to optimize antibiotic use and improve patient outcomes, including reductions in antibiotic resistance and treatment of sepsis. The Centers for Disease Control and Prevention's Division of Healthcare Quality Promotion hosted a meeting on improving patient safety through diagnostic stewardship with a focus on use of the laboratory. At the meeting, emerging issues in the field of diagnostic stewardship were identified, awareness of these issues among stakeholders was raised, and strategies and interventions to address the issues were discussed-all with an emphasis on improved outcomes and patient safety. Here, we summarize the key takeaways of the meeting including needs for diagnostic stewardship implementation, promising future avenues for diagnostic stewardship implementation, and areas of needed research.

Clinical Decision Support Systems to Reduce Unnecessary Clostridioides difficile Testing Across Multiple Hospitals.

BACKGROUND: Inappropriate Clostridioides difficile testing has adverse consequences for patients, hospitals, and public health. Computerized clinical decision support (CCDS) systems in the electronic health record (EHR) may reduce C. difficile test ordering; however, effectiveness of different approaches, ease of use, and best fit into healthcare providers' (HCP) workflow are not well understood. METHODS: Nine academic and 6 community hospitals in the United States participated in this 2-year cohort study. CCDS (hard stop or soft stop) triggered when a duplicate C. difficile test order was attempted or if laxatives were recently received. The primary outcome was the difference in testing rates pre- and post-CCDS interventions, using incidence rate ratios (IRRs) and mixed-effect Poisson regression models. We performed qualitative evaluation (contextual inquiry, interviews, focus groups) based on a human factors model. We identified themes using a codebook with primary nodes and subnodes. RESULTS: In 9 hospitals implementing hard-stop CCDS and 4 hospitals implementing soft-stop CCDS, C. difficile testing incidence rate (IR) reduction was 33% (95% confidence interval [CI]: 30%-36%) and 23% (95% CI: 21%-25%), respectively. Two hospitals implemented a non-EHR-based human intervention with IR reduction of 21% (95% CI: 15%-28%). HCPs reported generally favorable experiences and highlighted time efficiencies such as inclusion of the patient's most recent laxative administration on the CCDS. Organizational factors, including hierarchical cultures and communication between HCPs caring for the same patient, impact CCDS acceptance and integration. CONCLUSIONS: CCDS systems reduced unnecessary C. difficile testing and were perceived positively by HCPs when integrated into their workflow and when displaying relevant patient-specific information needed for decision making.

Temporal Trends of Candidemia Incidence Rates and Potential Contributions of Infection Control Initiatives Over 18 Years Within the United States Veterans Health Administration System: A Joinpoint Time-Series Analysis.

BACKGROUND: Candidemia is one of the most common causes of nosocomial bloodstream infections, but the impacts of factors affecting its incidence have not been evaluated. METHODS: We analyzed a retrospective cohort of all candidemia patients at 130 acute care hospitals in the Veterans Health Administration (VHA) system from January 2000 through December 2017. Cases were classified as hospital-onset (HO) and non-hospital-onset (NHO). We used Joinpoint regression analysis to assess temporal associations between significant changes in candidemia incidence rates and guidelines or horizontal infection control (IC) interventions. RESULTS: Over 18 years, 17 661 candidemia episodes were identified. Incidence rates of HO cases were increasing until the mid-2000s, followed by a sustained decline, while NHO cases showed a steady decline. The first change in HO candidemia incidence rates (August 2004 [95% confidence interval {CI}, February 2003-April 2005]) was preceded by the publication of catheter-related bloodstream infection (CRBSI) prevention guidelines and the CRBSI surveillance initiation. The second (September 2007 [95% CI, September 2006-June 2009]) had close temporal proximity to the expansion of IC resources within the VHA system. Collectively, these trend changes resulted in a 77.1% reduction in HO candidemia incidence rates since its peak in 2004. CONCLUSIONS: A substantial and sustained systemwide reduction in candidemia incidence rates was observed after the publication of guidelines, VHA initiatives about CRBSI reporting and education on CRBSI prevention, and the systemwide expansion of IC resources.

Coronavirus Disease 2019 Serial Testing Among Hospitalized Patients in a Midwest Tertiary Medical Center, July-September 2020.

We implemented serial coronavirus disease 2019 testing for inpatients with a negative test on admission. The conversion rate (negative to positive) on repeat testing was 1%. We identified patients during their incubation period and hospital-onset cases, rapidly isolated them, and potentially reduced exposures. Serial testing and infectiousness determination were resource intensive.

Palliative care consultation in patients with Staphylococcus aureus bacteremia.

BACKGROUND: Palliative care consultation has shown benefits across a wide spectrum of diseases, but the utility in patients with Staphylococcus aureus bacteremia remains unclear despite its high mortality. AIM: To examine the frequency of palliative care consultation and factors associated with palliative care consult in Staphylococcus aureus bacteremia patients in the United States. DESIGN: A population-based retrospective analysis using the Nationwide Inpatient Sample database in 2014, compiled by the Healthcare Costs and Utilization Project of the Agency for Healthcare Research and Quality. SETTING/SUBJECTS: All inpatients with a discharge diagnosis of Staphylococcus aureus bacteremia (ICD-9-CM codes; 038.11 and 038.12). MEASUREMENTS: Palliative care consultation was identified using ICD-9-CM code V66.7. Patients' baseline characteristics and outcomes were compared between those with and without palliative care consult. RESULTS: A total of 111,320 Staphylococcus aureus bacteremia admissions were identified in 2014. Palliative care consult was observed in 8140 admissions (7.3%). Palliative care consultation was associated with advanced age, white race, comorbidities, higher income, teaching/urban hospitals, Midwest region, Methicillin-resistant Staphylococcus aureus bacteremia and the lack of echocardiogram. Palliative care consult was also associated with shorter but more expensive hospitalizations. Crude mortality was 53% (4314/8140) among admissions with palliative care consult and 8% (8357/10,3180) among those without palliative care consult (p < 0.001). CONCLUSIONS: Palliative care consultation was infrequent during the management of Staphylococcus aureus bacteremia, and a substantial number of patients died during their hospitalizations without palliative care consult. Given the reported benefit in other medical conditions, palliative care consultation may have a role in Staphylococcus aureus bacteremia. Selecting patients who may benefit the most should be explored.

Practical Guidance for Clinical Microbiology Laboratories: A Comprehensive Update on the Problem of Blood Culture Contamination and a Discussion of Methods for Addressing the Problem

In this review, we present a comprehensive discussion of matters related to the problem of blood culture contamination. Issues addressed include the scope and magnitude of the problem, the bacteria most often recognized as contaminants, the impact of blood culture contamination on clinical microbiology laboratory function, the economic and clinical ramifications of contamination, and, perhaps most importantly, a systematic discussion of solutions to the problem. We conclude by providing a series of unanswered questions that pertain to this important issue.

Correlation between Broth Microdilution and Disk Diffusion Results when Testing Ceftazidime-Avibactam against a Challenge Collection of Enterobacterales Isolates: Results from a Multilaboratory Study.

We assessed the ceftazidime-avibactam disk diffusion breakpoints that provide the lowest discrepancy error rates by testing an Enterobacterales isolate collection with ceftazidime-avibactam MIC values near the breakpoints. Isolates (n = 112) were susceptibility tested by broth microdilution and disk diffusion methods in 3 laboratories. Current disk diffusion breakpoints (≥21/≤20 mm for susceptible/resistant) provided the lowest error rates, but confirmatory MIC testing is indicated for isolates with inhibition zones of 20 to 22 mm.

Genomic Analysis of Cardiac Surgery-Associated Mycobacterium chimaera Infections, United States.

A surgical heater-cooler unit has been implicated as the source for Mycobacterium chimaera infections among cardiac surgery patients in several countries. We isolated M. chimaera from heater-cooler units and patient infections in the United States. Whole-genome sequencing corroborated a risk for these units acting as a reservoir for this pathogen.

The Microbiology of Bloodstream Infection: 20-Year Trends from the SENTRY Antimicrobial Surveillance Program.

Bloodstream infection (BSI) organisms were consecutively collected from >200 medical centers in 45 nations between 1997 and 2016. Species identification and susceptibility testing followed Clinical and Laboratory Standards Institute broth microdilution methods at a central laboratory. Clinical data and isolates from 264,901 BSI episodes were collected. The most common pathogen overall was Staphylococcus aureus (20.7%), followed by Escherichia coli (20.5%), Klebsiella pneumoniae (7.7%), Pseudomonas aeruginosa (5.3%), and Enterococcus faecalis (5.2%). S. aureus was the most frequently isolated pathogen overall in the 1997-to-2004 period, but E. coli was the most common after 2005. Pathogen frequency varied by geographic region, hospital-onset or community-onset status, and patient age. The prevalence of S. aureus isolates resistant to oxacillin (ORSA) increased until 2005 to 2008 and then declined among hospital-onset and community-acquired BSI in all regions. The prevalence of vancomycin-resistant enterococci (VRE) was stable after 2012 (16.4% overall). Daptomycin resistance among S. aureus and enterococci (DRE) remained rare (<0.1%). In contrast, the prevalence of multidrug-resistant (MDR) Enterobacteriaceae increased from 6.2% in 1997 to 2000 to 15.8% in 2013 to 2016. MDR rates were highest among nonfermentative Gram-negative bacilli (GNB), and colistin was the only agent with predictable activity against Acinetobacter baumannii-Acinetobacter calcoaceticus complex (97% susceptible). In conclusion, S. aureus and E. coli were the predominant causes of BSI worldwide during this 20-year surveillance period. Important resistant phenotypes among Gram-positive pathogens (MRSA, VRE, or DRE) were stable or declining, whereas the prevalence of MDR-GNB increased continuously during the monitored period. MDR-GNB represent the greatest therapeutic challenge among common bacterial BSI pathogens.

MYCOBACTERIUM CHIMAERA INFECTIONS AFTER CARDIOVASCULAR SURGERY: LESSONS FROM A GLOBAL OUTBREAK.

A global outbreak of invasive Mycobacterium chimaera infections has been associated with exposure to certain heater-cooler devices (HCDs) used during cardiopulmonary bypass. Outbreak investigations have shown that these HCDs harbor M. chimaera in water circuits and generate bio-aerosols in the operating room, leading to airborne transmission to patients during surgery. Whole genome sequencing data support a common-source outbreak originating at an HCD manufacturing facility. Most clinical infections are associated with implanted devices, diagnosis is often delayed, and treatment requires device removal and prolonged antibiotic therapy. Because it is nearly impossible to eradicate M. chimaera from HCDs using existing disinfection approaches, strict separation of HCD exhaust from operating room air is necessary to prevent patient exposure. Lessons learned from this outbreak include: 1) medical device risks are difficult to predict, requiring improved expert review before approval, and 2) advances in genomics provide powerful tools for outbreak investigation and public health surveillance.

Point-Counterpoint: Active Surveillance for Carriers of Toxigenic Clostridium difficile Should Be Performed To Guide Prevention Efforts.

INTRODUCTIONIn 2017, the Journal of Clinical Microbiology published a Point-Counterpoint on the laboratory diagnosis of Clostridium difficile infection (CDI). At that time, Ferric C. Fang, Christopher R. Polage, and Mark H. Wilcox discussed the strategies for diagnosing Clostridium difficile colitis in symptomatic patients (J Clin Microbiol 55:670-680, 2017, https://doi.org/10.1128/JCM.02463-16). Since that paper, new guidelines from the Infectious Diseases Society of America and the Society for Health Care Epidemiology have been published (L. C. McDonald, D. N. Gerding, S. Johnson, J. S. Bakken, K. C. Carroll, et al., Clin Infect Dis 66:987-994, 2018, https://doi.org/10.1093/cid/ciy149) and health care systems have begun to explore screening asymptomatic patients for C. difficile colonization. The theory behind screening selected patient populations for C. difficile colonization is that these patients represent a substantial reservoir of the bacteria and can transfer the bacteria to other patients. Hospital administrators are taking note of institutional CDI rates because they are publicly reported. They have become an important metric impacting hospital safety ratings and value-based purchasing, and hospitals may have millions of dollars of reimbursement at risk. In this Point-Counterpoint, Cliff McDonald of the U.S. Centers for Disease Control and Prevention discusses the value of asymptomatic C. difficile screening, while Dan Diekema of the University of Iowa discusses why caution should be used.

Diagnostic Stewardship to Prevent Diagnostic Error.

This Viewpoint discusses the growth of diagnostic stewardship beyond infectious disease to reduce diagnostic errors in other fields.

Mycobacterium chimaera Infections Associated With Contaminated Heater-Cooler Devices for Cardiac Surgery: Outbreak Management.

The global outbreak of Mycobacterium chimaera infections associated with heater-cooler devices (HCDs) presents several important, unique challenges for the infection prevention community. The primary focus of this article is to assist hospitals in establishing a rapid response for identification, notification, and evaluation of exposed patients, and management of HCDs with regard to placement and containment, environmental culturing, and disinfection.

Rising Stakes for Health Care-Associated Infection Prevention: Implications for the Clinical Microbiology Laboratory.

Health care-associated infection (HAI) rates are subject to public reporting and are linked to hospital reimbursement from the Centers for Medicare and Medicaid Services (CMS). The increasing pressure to lower HAI rates comes at a time when advances in the clinical microbiology laboratory (CML) provide more-precise and -sensitive tests, altering HAI detection in ways that may increase reported HAI rates. I review how changing CML practices can impact HAI rates and how the financial implications of HAI metrics may produce pressure to change diagnostic testing practices. Finally, I provide suggestions for how to respond to this rapidly changing environment.