Shira R. Abeles

The Centers for Disease Control and Prevention has recommended contact precautions for healthcare personnel caring for COVID-19 patients since the beginning of the pandemic. However, current scientific evidence points to transmission through small respiratory droplets or aerosols and not contaminated fomites as the dominant routes of transmission of SARS-CoV-2. We believe science shows there is no benefit and thus only negative consequences to patients, the environment, and the U.S healthcare system associated with ongoing contact precautions for patients with SARS-CoV-2 infection, and we advocate for updated guidelines reflecting current science.

Background: The Karius Test (KT), a microbial cell-free DNA next-generation sequencing assay, is increasingly utilized in challenging infectious syndromes. However, its real-world clinical utility and cost-effectiveness remain uncertain. Methods: We conducted a retrospective review of 88 KT results from adult patients at UC San Diego Health between July 2017 and April 2024. Each case was evaluated for clinical impact using standardized criteria. We analyzed diagnostic yield, turnaround time, number needed to test (NNT), and institutional billing data for reimbursement and cost implications. Results: Of 88 unique tests, forty-nine (55.7%) identified at least one pathogen. Eleven (12.5%) had a positive clinical impact—eight provided the only microbiologic diagnosis, and three were faster than conventional methods. Vascular/graft infections showed the highest yield. Twenty-one tests had a neutral impact; fifty-six showed no clinical benefit. The Median turnaround time was 3 days. The NNT was 6.1 or 2.75 including neutral cases. Cost analysis revealed a substantial financial burden without transparent reimbursement mechanisms in inpatient settings. Conclusion: The KT demonstrates modest clinical utility with noteworthy benefits in select scenarios. Given its high cost and variable impact, we advocate for diagnostic stewardship led by infectious disease specialists to optimize test use and minimize unnecessary expense.

Infection prevention and control, or IP&C, is a critical stakeholder in advancing environmental sustainability in health care. IP&C activities seek to ensure safety of processes in health care from an infection perspective, but how these are performed can drive substantial waste and pollution. There are certain IP&C measures that can, without compromising safety or efficiency, be adapted to more environmentally friendly practices and have a high impact benefit to sustainability without affecting patient outcomes. Moreover, IP&C practice stands to be significantly altered by climate change and pollution. Here, we describe the complex interdependence between sustainability, climate change, and IP&C, and opportunities for IP&C to be at the leading edge of optimizing healthcare's environmental footprint.

Purpose of review: This review covers recent research regarding the challenges posed by climate change within the areas of antimicrobial stewardship and infection prevention, and ways to build resiliency in these fields. Recent findings: Infectious disease patterns are changing as microbes adapt to climate change and changing environmental factors. Capacity for testing and treating infectious diseases is challenged by newly emerging diseases, which exacerbate challenges to antimicrobial stewardship and infection prevention. Antimicrobial resistance is accelerated due to environmental factors including air pollution, plastic pollution, and chemicals used in food systems, which are all impacted by climate change. Climate change places infection prevention practices at risk in many ways including from major weather events, increased risk of epidemics, and societal disruptions causing conditions that can overwhelm health systems. Researchers are building resilience by advancing rapid diagnostics and disease modeling, and identifying highly reliable versus low efficiency interventions. Summary: Climate change and associated major weather and socioeconomic events will place significant strain on healthcare facilities. Work being done to advance rapid diagnostics, build supply chain resilience, improve predictive disease modeling and surveillance, and identify high reliability versus low yield interventions will help build resiliency in antimicrobial stewardship and infection prevention for escalating challenges due to climate change.

Michael B Doud, MD PhD, Nina M Haste, PharmD PhD, Shira R Abeles, MD; Correspondence to Hasegawa et al. “Diagnostic Accuracy of Hospital Antibiograms in Predict

Background: Pre-exposure prophylaxis for COVID-19 with tixagevimab/cilgavimab (T/C) received Emergency Use Authorization (EUA) based on results of a clinical trial conducted prior to the emergence of the Omicron variant. The clinical effectiveness of T/C has not been well described in the Omicron era. We examined the incidence of symptomatic illness and hospitalizations among T/C recipients when Omicron accounted for virtually all local cases. Methods: Through retrospective electronic medical record chart review, we identified patients who received T/C between January 1 –July 31, 2022 within our quaternary referral health system. We determined the incidence of symptomatic COVID-19 infections and hospitalizations due to or presumed to be caused by early Omicron variants before and after receiving T/C (pre-T/C and post-T/C). Chi square and Mann-Whitney Wilcoxon two-sample tests were used to examine differences between the characteristics of those who got COVID-19 before or after T/C prophylaxis, and rate ratios (RR) and 95% confidence intervals (CI) were calculated to assess differences in hospitalization rates for the two groups. Results: Of 1295 T/C recipients, 105 (8.1%) developed symptomatic COVID-19 infection before receiving T/C, and 102 (7.9%) developed symptomatic disease after receiving it. Of the 105 patients who developed symptomatic infection pre-T/C, 26 (24.8%) were hospitalized, compared with six of the 102 patients (5.9%) who were diagnosed with COVID-19 post-T/C (RR = 0.24; 95% CI = 0.10–0.55; p = 0.0002). Seven of the 105 (6.7%) patients infected pre-T/C, but none of the 102 infected post-T/C required ICU care. No COVID-related deaths occurred in either group. The majority of COVID-19 cases among those infected pre-T/C treatment occurred during the Omicron BA.1 surge, while the majority of post-T/C cases occurred when Omicron BA.5 was predominant. In both groups, having at least one dose of vaccine strongly protected against hospitalization (pre-T/C group RR = 0.31, 95% CI = 0.17–0.57, p = 0.02; post-T/C group RR = 0.15; 95% CI = 0.03–0.94; p = 0.04). Conclusion: We identified COVID-19 infections after T/C prophylaxis. Among patients who received T/C at our institution, COVID-19 Omicron cases occurring after T/C were one-fourth as likely to require hospitalization compared to those with Omicron prior to T/C. However, due to the presence of changing vaccine coverage, multiple therapies, and changing variants, the effectiveness of T/C in the Omicron era remains difficult to assess.

Within 5 months, an emerging human monkeypox virus (MPXV) pandemic has caused >65,000 cases, leading the World Health Organization to declare it a public health emergency of international concern (PHEIC). Applying former United States Secretary of Defense Donald Rumsfeld’s idiom, we reflect upon the “known knowns,” “known unknowns,” and “unknown unknowns” to improve prevention and treatment for this and future pandemics.

Background: Pre-exposure prophylaxis for COVID-19 with tixagevimab/cilgavimab (T/C) received Emergency Use Authorization (EUA) based off of results from a clinical trial conducted prior to the Omicron variant. Its clinical effectiveness has not been well described in the Omicron era. We examined the incidence of symptomatic illness and hospitalizations among T/C recipients when Omicron accounted for virtually all cases. Methods: We used the electronic medical record to identify patients who received T/C at our institution. Among these patients, we assessed for cases of symptomatic COVID-19 and associated hospitalizations before and after receiving T/C. We used chi square tests and Fishers exact p-values to examine differences between characteristics of those who got COVID before and after T/C prophylaxis. Results: Of 1295 T/C recipients, 121 (9.3%) developed symptomatic COVID-19 before receiving T/C, and 102 (7.9%) developed symptomatic disease after receiving it. Among those with infection prior to T/C, 36/121 (29.8%) were hospitalized, including 8 (6.6%) admitted to the ICU. Among those with COVID-19 after receiving T/C, 6/102 (5.9%) were hospitalized but none required ICU admission. No COVID-related deaths occurred in either group. The majority of COVID-19 cases among those infected prior to T/C treatment occurred during Omicron BA.1 surge, while the majority of cases among post-T/C recipients occurred when BA.5 was predominant. Patients infected with COVID-19 prior to receiving T/C had received fewer vaccine doses and were less likely to receive COVID-19 therapeutics compared to those with COVID-19 after having received T/C. Conclusion: We identified COVID-19 infections after T/C prophylaxis. Among persons eligible for T/C, COVID-19 illnesses occurring after T/C were less likely to require hospitalization compared to those with COVID-19 prior to T/C. In the presence of changing vaccine coverage, multiple therapies, and changing variants, the effectiveness of T/C in the Omicron era remains difficult to assess.