Discussion
infectious, infections, infection, nosocomial, deaths
INFECTION, SARS-COV-2 INFECTION, INFECTIONS
During this large-scale study in EDs, we found that an intensified screening strategy for SARS-CoV-2 was unlikely to identify a substantial proportion of new diagnoses. Compared to the asymptomatic population screened in the region, the asymptomatic/paucisymptomatic ED population screened by nurses appears to have been more affected. Comparison with a mathematical model indicated that the ED data allowed for the estimation of regional incidences for asymptomatic/paucisymptomatic SARS-CoV-2 infections.In this study, screening for asymptomatic/paucisymptomatic patients led to the detection of SARS-CoV-2 in more than 200 patients. Almost all these patients were outpatients who would not otherwise have been screened during their visit. Despite a trend in the primary outcome analysis toward an increased detection of infections with the intervention, the 95% CI provided no support for values of importance, ranging from an 11% increase, which is of clinical interest, to a 6% decrease. Several reasons may explain these findings.First, 21% of the patients who visited the EDs were admitted and screened. When combined with the screening of symptomatic patients, more than 25% of patients were routinely screened. This high proportion of detection, facilitated by using fast molecular assays as point-of-care tests in half of the centers, is unprecedented and could have lowered the impact of the intervention.Second, the findings could be related to a highly fluctuating evolution of the COVID-19 epidemic during the study [Third, out-of-hospital screening was generalized during the study period, possibly reducing the impact of the intervention. In 2021, 35 million tests were recorded in the Paris metropolitan area [In this study, almost half of the asymptomatic/paucisymptomatic patients screened had not been previously tested for SARS-CoV-2, suggesting limited access to health care. The proportion of new diagnoses in this asymptomatic/paucisymptomatic population in EDs seemed to be higher than that in the asymptomatic population screened during the same period in the region. Positivity appeared higher in EDs in individuals born in countries other than France, corroborating studies reporting higher infection rates in minority groups [Data from the implementation of the intensified SARS-CoV-2 screening strategy in EDs are difficult to compare. Most studies evaluating the effectiveness of SARS-CoV-2 screening in adult EDs either focus on screening symptomatic patients for diagnostic purposes or screening admitted patients to reduce nosocomial transmission, are modeling studies, or report on the accuracy of screening tests.Evaluation of community-based SARS-CoV-2 screening programs for asymptomatic individuals have involved few controlled comparisons of key health outcomes, such as the detection of positive cases, timely isolation of infectious individuals and their close contacts, transmissions, hospital admissions, or deaths. Furthermore, the evaluations conducted have often failed to distinguish between the impact of mass screening and a combination of other control measures introduced simultaneously. Large-scale community screening evaluated in 3 countries at rapidly growing phases of the epidemic appeared to have the potential to reduce prevalence, transmission, or subsequent hospitalizations, at least in the short term [Comparative evaluation of screening activities is crucial for identifying effective and equitable responses [There is concern that adding screening will have unintended consequences for ED workload. Contrasting results are reported on the impact of inpatient screening on ED length of stay [In terms of limitations, in addition to the factors described, including the high fluctuation during the epidemic which may have reduced the impact of the intervention, during this study, 14% of eligible ED patients completed the questionnaire, which was the first stage of the nurse-driven screening strategy for asymptomatic/paucisymptomatic individuals, 67% of whom were screened. This is inherent to screening strategies in EDs, in which the proportion of patients involved in the screening process rarely exceeds 20% [A rapid isothermal amplification assay was used for biosafety reasons and rapid turnaround time [For reasons of feasibility, our study could not include an evaluation of the costs in the 2 groups compared or an examination of the choice of tests. This is a major area since decisions about the adoption of control measures must reflect both effectiveness and costs [Given the considerable asymptomatic transmission of SARS-CoV-2 infection, screening is a key nonpharmaceutical measure for identifying infectious individuals, limiting transmission, and containing the epidemic. During a rapidly evolving epidemic phase, we observed that the intensified screening strategy in EDs was unlikely to increase detection. However, comparing ED screening data with a mathematical model was encouraging, as it allowed estimation of regional incidences for both asymptomatic/paucisymptomatic SARS-CoV-2 infections and total cases. This approach can potentially be used to estimate the size of the epidemic in the population and the underdetection of cases in community surveillance [The findings underline the need to further explore, using robust evaluation methods, ED strategies for the detection of SARS-CoV-2, or asymptomatically transmitted respiratory viruses to better define the observatory role of EDs in emerging epidemics.In conclusion, the results of this study showed that intensified ED screening was unlikely to bring a substantial benefit to the detection of SARS-CoV-2 infections. This strategy could facilitate access to a population that appears to be more affected than the population of the region and could help to estimate the incidence of asymptomatic/paucisymptomatic infections.