Diagnostic Justice

Diagnostic testing can be used for many purposes, including testing to facilitate the clinical care of individual patients, testing as an inclusion criterion for clinical trial participation, and both passive and active surveillance testing of the general population in order to facilitate public health outcomes, such as the containment or mitigation of an infectious disease. As such, diagnostic testing presents us with ethical questions that are, in part, already addressed in the literature on clinical care as well as clinical research (such as the rights of patients to refuse testing or treatment in the clinical setting or the rights of participants in randomized controlled trials to withdraw from the trial at any time). However, diagnostic testing, for the purpose of disease surveillance also raises ethical issues that we do not encounter in these settings, and thus have not been much discussed. In this paper we will be concerned with the similarities and differences between the ethical considerations in these three domains: clinical care, clinical research, and public health, as they relate to diagnostic testing specifically. Via an examination of the COVID-19 case we will show how an appeal to the concept of diagnostic justice helps us to make sense of the (at times competing) ethical considerations in these three domains.

COVID-19 Active Surveillance Simulation Case Study - Health and Economic Impacts of Active Surveillance in a School Environment

The COVID-19 pandemic has affected the lives of almost all human beings and has forced stay-at-home mandates across the world. Government and school officials are facing challenging decisions on how to start the new 2020/2021 school year. Almost every school system has chosen a remote learning model for the Fall of 2020 while many are facing financial and logistical challenges.In this study, we explore the efficacy of an Active Surveillance testing model where a random number of students are tested daily for early detection of asymptomatic patients and for prevention of the infection among the student population. In addition to health impacts, we also analyze the financial impact of deploying the Active Surveillance system in schools while taking into consideration lost workdays of parents, hospitalization costs, and testing costs.Under the given assumptions, initial modeling results indicate that low Active Surveillance testing rates (between 6-10% daily testing of student population) can help achieve low infection rates (≤10%) among students along with enforcing mitigation procedures, such as wearing masks and social distancing. Without enforcing mitigation procedures, the optimal Active Surveillance rate of 8-10% can also achieve (≤10%) infection rates among student population. The results also demonstrate that Active Surveillance can lower the financial burden of the pandemic by proactively lowering the infection rates among student populations.

537. Impact of Active Surveillance Testing (AST) on Rates of Hospital-acquired Carbapenem-Resistant Enterobacteriaceae (CRE)

Background Active surveillance testing (AST) for Carbapenem-resistant Enterobacteriaceae (CRE) to identify and isolate asymptomatic carriers has been recommended to help prevent patient to patient transmission. Optimal screening population, frequency, and testing method remain a subject of debate. Methods Beginning in 2012, all clinical cultures yielding a CRE isolate in an 898-bed teaching hospital were reviewed to determine whether the isolate was hospital-acquired (HA). HA CRE rates per 10,000 patient-days were calculated. From 1/2013 to 6/2015, in-house, culture-based point prevalence surveys were performed on rectal swabs from rotating units using the CDC recommended method. 7/2015 through 8/2016, culture-based AST was outsourced to a reference laboratory and AST was expanded to include high-risk patients on admission with weekly sweeps on high-risk units. Of note, revised CLSI breakpoints were implemented by our laboratory in 7/2016, which resulted in an increase in CRE detections. Surveillance was suspended from September 2016 to January 2018 when we resumed AST utilizing in-house PCR for KPC, NDM, OXA48, IMP and VIM mechanisms. Rates of HA CRE were compared between surveillance periods. Cohorting of patients in select units, focus on hand hygiene and isolation, antibiotic stewardship, and CHG bathing were ongoing throughout all time periods. Results 510 rectal swabs in 424 patients were positive for CRE. Additional clinical cultures yielding CRE were absent in 83% of those patients, so would otherwise have gone undetected. Of those patients with both positive AST and clinical culture, 70% had a positive AST result prior to their clinical culture (range 0–997 days, average 94 days, median 14.5 days prior to clinical culture). Compared with preceding periods with no surveillance, on admission and weekly CRE AST, whether utilizing culture based or PCR based screening, was associated with significantly lower rates of HA CRE. (See Table 1). Rates of HA CRE during the initial point prevalence AST period were unchanged compared with periods with no surveillance. Community-onset CRE did not significantly change in any of the time periods monitored (Figure 2). Conclusion On admission and weekly AST was associated with a significant decrease in HA CRE in a large teaching hospital. Disclosures All authors: No reported disclosures.

Validation of Active Surveillance Testing for Clostridium difficile Colonization Using the cobas Cdiff Test

ABSTRACT Clostridium difficile infection (CDI) is not declining in the United States. Nucleic acid amplification tests (NAAT) are used as part of active surveillance testing programs to prevent health care-associated infection. The objective of this study was to validate the cobas Cdiff Test on the cobas 4800 System (cobas) within a four-hospital system using prospectively collected perirectal swabs from asymptomatic patients at admission and during monthly intensive care unit (ICU) screening in an infection control CDI reduction program. Performance of the cobas was compared to that of toxigenic culture. Each positive cobas sample and the next following negative patient swab were cultured. The study design gave 273 samples processed by both cobas (137 positive and 136 negative) and culture (one negative swab was not cultured). Discrepant analysis was performed using a second NAAT, the Xpert C. difficile Epi test (Xpert). This strategy was compared to a medical record review for antibiotic receipt that would inhibit growth of C. difficile in colonic stool. None of the cobas-negative samples were culture positive. The cobas positive predictive value was 75.2% (95% confidence interval [CI], 66.9% to 82%) and positive percent agreement was 100% (95% CI, 96.0% to 100%). Overall agreement between cobas and direct toxigenic culture was 87.6% (95% CI, 83.1% to 91%). For the cobas-positive/culture-negative (discrepant) samples, 7 Xpert-positive samples were from patients receiving inhibitory antimicrobials; only 4 of 23 Xpert-negative samples received these agents ( P = 0.00006). Our results support use of the cobas as a reliable assay for an active surveillance testing program to detect asymptomatic carriers of toxigenic C. difficile .