ABSTRACT
Background: As COVID-19 cases persist, one potential intervention to reduce absenteeism in the workplace due to COVID-19 is to use rapid antigen diagnostics to mitigate the spread of SARS-CoV-2. Furthermore, routine testing in the workplace offers an avenue to reaching a large proportion of the population which could lead to a greater community impact beyond solely mitigating transmission events that occur in the workplace. We sought to identify the most cost-effective workplace testing strategies at the community level and within individual workplaces. Method(s): We used two models to understand how SARS-CoV-2 AgRDTs could best be implemented within the workplace to mitigate the spread of COVID-19. In our community-level dynamic transmission model, PATAT, we evaluated the impact of symptomatic testing and asymptomatic testing of a fixed proportion of the formally employed workforce on broader community transmission. We stratified runs by asymptomatic testing frequency, vaccine coverage, vaccine effectiveness, and Rt. Simulations were informed using demographic data from Georgia, Brazil, and the Netherlands. We conducted a cost-effectiveness analysis using the results from each country and assumed a $2.50 total cost per test. Result(s): We observed a substantial decrease in the number of infections occurring in both the workplace and community when a SARS-CoV-2 AgRDTs strategy was implemented. Under all conditions, mandatory symptomatic testing and related quarantine from the workplace averted up to 72%, 79%, and 74% of community infections in Brazil, Georgia, and the Netherlands respectively. Limiting tests to symptomatic workers was always on the cost-effectiveness frontier, regardless of the vaccine coverage, efficacy, or Rt of the virus (Figure 1), at $2-$4 per workplace infection prevented. While asymptomatic testing was on the cost-effectiveness frontier, it would cost an additional $500-$6700 to prevent one additional workplace infection. The added benefit of routine asymptomatic testing was minimal until 100% of the workforce was reached. Conclusion(s): We found self-testing with AgRDTs for the formally employed workforce is both efficient at reducing workplace and community infections as well as cost-effective when targeting symptomatic individuals. Willingness to pay to avoid workplace absenteeism may differ by country, individual workplaces, and the perceived economic value of several workdays missed. If there is a higher willingness to pay, routine asymptomatic screening may be considered.
ABSTRACT
Background: Throughout the COVID-19 pandemic, it was evident that many SARS-CoV-2 infections occurred at mass gathering events. In many LMICs and LICs, places of worship serve as a venue for mass gatherings, and therefore a potential source of large-scale transmission events. Mass gatherings at places of worship also serve as an opportunity to distribute Ag-RDTs to a significant proportion of the community at regular intervals, disrupting transmission within the event and potentially impacting community spread of SARS-CoV-2. Method(s): We used an agent-based community assessment model, Propelling Action for Testing and Treatment, to estimate how various strategies of asymptomatic Ag-RDT self-testing of a fixed percentage of persons attending large religious gatherings (10%, 20%, 40%, 100%), in addition to the general underlying level of ongoing symptomatic testing in the population, would impact community transmission of SARS-CoV-2 in 3 contexts (Brazil, Georgia, Zambia). These testing strategies were analyzed with bi-weekly and weekly asymptomatic self-testing in a population with varying levels of vaccine efficacy (low/high), vaccine coverage (10%, 50%, 80%), and reproductive numbers (0.9, 1.2, 1.5, and 2.0) to simulate varying stages of the COVID-19 pandemic. We then performed an economical evaluation of the results from the model to understand the impact and cost-effectiveness of each self-testing strategy at places of worship. Result(s): In each of the epidemic conditions modeled, testing of symptomatic persons at weekly and biweekly frequencies can avert 2%-16% of Brazilian community infections and 31%-45% of infections occurring in places of worship in Brazil. The same is true in Georgia (1%-6% of total infections and 28%-45% place of worship-related infections) and Zambia (2%-21% of total infections and 29%-45% of place of worship related infections) despite differences in the proportion of populations regularly attending places of worship in the 3 countries. Asymptomatic self-testing in 100% of places of worship in a country result in the greatest percent of infections averted and consistently lands on the cost-effectiveness frontier yet requires a budget 520- 1550x greater than that of symptomatic testing alone. Conclusion(s): Testing of symptomatic persons attending regular religious gatherings have a significant impact on the spread of SARS-CoV-2 in places of worship and can significantly reduce community spread in contexts where population level attendance at religious gatherings is high. Cost-effectiveness analysis from Brazil, Georgia and Zambia modelling results with infections averted within places of worship and total community infections averted assuming a total cost per self-test of $2.50 USD.
ABSTRACT
Background: Despite widespread vaccination and increasing population immunity from previous infections, community transmission of COVID-19 continues, and testing may continue to be an important component of our response particularly with the proliferation of new variants of concern. Strategic deployment of SARS-CoV-2 antigen-detection rapid diagnostic (AgRDT) self-tests to settings with increased transmission potential can reduce the viral burden within the specific settings, such as in K-12 schools, and may have spillover benefits for broader community transmission. Method(s): Using a previously developed agent-based simulation model, parameterized to three distinct country archetypes (Brazil, Georgia, Zambia), we analyzed 11 different self-testing strategies within the school-going population at three testing frequencies under 24 different epidemic conditions (Rt, vaccination coverage/effectiveness), comprising a total of 696 scenarios per country. Strategies included symptomatic testing, and in addition, asymptomatic testing at 5, 20, 40 or 100% of schools, or asymptomatic contact testing. These were all targeted to either only teachers or teachers and students. Then, with the cost to offer a COVID-19 self-test in schools at USD 2.50, we performed an economic analysis with all scenarios to identify the most costeffective strategies by country. Result(s): Routine asymptomatic testing of teachers and students at 100% of schools reduced the greatest number of infections across contexts, but at the greatest cost. However, with respect to both the reduction in infections and total cost, symptomatic testing of all teachers and students appears to be the most efficient strategy. Symptomatic testing can prevent up to 69.3%, 64.5%, and 75.5% of school infections in Brazil, Georgia, and Zambia, across all epidemic conditions. Additionally, it can prevent up to 77,200, 80,900, 107,800 symptomatic days per 100,000 teachers and students in each country, respectively, over the course of a 90-day epidemic wave. The incremental cost-effectiveness ratios for strategies that consistently appeared on the costeffectiveness frontier across countries and epidemic conditions are shown in Figure 1 for an Rt of 1.2. Conclusion(s): If financial resources are limited, symptomatic testing of teachers and students has the potential to be cost-effective while reducing a substantial number of infections and the amount of time lost from the classroom, making it a feasible strategy for implementation in a variety of settings.
ABSTRACT
Introduction: There are reports of changes in the numbers of stroke admissions and time intervals to receiving emergency treatments during the COVID-19 pandemic. We examined the impact of the COVID-19 pandemic on the stroke thrombolysis rate and delay to thrombolysis treatment in a regional stroke centre in London, UK. Methods: COVID-19 testing began at our hospital on 3 March 2020. Clinical data for all acute stroke admissions were routinely collected as part of a national Sentinel Stroke National Audit Programme (SSNAP) and all thrombolysis data were entered into our local thrombolysis database. We retrospectively extracted the relevant patient data for the period of March to May 2020 (COVID group) and compared to the same period in 2019 (pre-COVID group). Results: Compared with pre-COVID, there was a 17.5% fall in total stroke admissions (from 315 to 260) during COVID;but there were no significant differences in the demographics, stroke severity, proportions with known time of onset, or median onset-to-arrival time. The thrombolysis rates amongst ischemic strokes were not significantly different between the two groups (59/260=23% pre- COVID vs. 41/228=18% COVID, p=.19). For thrombolysis patients, their stroke severity and demographics were similar between the two both groups. Median onset-to-needle time was significantly longer by 22 minutes during COVID [127 (IQR 94-160) vs. 149 (IQR 110-124) minutes, p=.045];this delay to treatment was almost entirely due to a longer median onset-to-arrival time by 16 minutes during COVID (p=.029). Favorable early neurological outcomes post-thrombolysis (defined as an improvement in NIHSS by ≥4 points at 24 hours) were similar (45% vs. 46%, p=.86). Conclusion: COVID-19 pandemic had a negative impact on prehospital delays which in turn significantly increased onset-to-needle time, but without affecting the chance of a favorable early neurological outcome. Our data highlight the need to maintain public awareness of taking immediate action when stroke symptoms occur during the COVID-19 pandemic.