In a recent study posted to medRxiv* pre-print server, researchers simulated several scenarios for the implementation of portable sensors to demonstrate the potential of digital contact tracking technology to alleviate the 2019 coronavirus disease pandemic (COVID-19).
Examination: Implementation of portable sensors to mitigate pandemics. Image Credit: Dark Moon Pictures
Outbreaks of infectious diseases, such as COVID-19, adversely affected public health and had socio-economic consequences. Research shows that implementing effective public health strategies, such as a “Find, Test, Trace, Isolate” (FTTI) strategy that identifies and quarantines infectious individuals to prevent further transmission, can help minimize the damage caused by pandemics.
During the COVID-19 pandemic, FTTI systems that relied on laboratory-based tests, such as reverse transcriptase-polymerase chain reaction (RT-PCR), failed to mitigate transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In particular, RT-PCR tests have a long treatment time and can not detect presymptomatic and asymptomatic SARS-CoV-2 infected individuals (forming a hidden chain of infection).
Digital contact tracking techniques, such as portable sensors, have the potential to fill these gaps and detect infections caused by respiratory pathogens, including SARS-CoV-2, before symptoms occur or even in the absence of symptoms. Portable sensors also offer the benefit of passive monitoring, which minimizes the need for user engagement and preserves users’ privacy (not shared with a centralized database).
As they offer several potential benefits, several studies have focused on the development of portable sensor-based algorithms for the detection of infectious diseases; however, no one has studied the impact of implementing these pandemic mitigation devices in a real world.
About the study
In this study, researchers built a compartmental epidemiological model based on a sensitive, exposed, contagious, removed (SEIR) framework in which portable devices notified users of potential SARS-CoV-2 infection and prompted them to seek a laboratory-based test and self-soles, while you await the result.
The study simulated the scenarios for implementing portable sensors during Canada’s second COVID-19 pandemic from September 1, 2020 to February 20, 2021. First, the researchers considered a basic scenario where portable device users could download an application with currently available detection algorithms. Next, they examined the impact of technology and behavioral parameters, such as detection accuracy, sensitivity, specificity, recording (defined as users who frequently wear wearables), and compliance (defined as users who take the appropriate next steps following a positive SARS-CoV announcement). -2 infection). In addition, the researchers tested a complementary approach using rapid antigen tests (RATs) to confirm SARS-CoV-2 infection reported by wearables.
Basic scenario for implementing portable sensors. Time series depiction of the incidence of infection (A), the number of users of portable devices quarantined incorrectly (B), and the daily demand for laboratory-based tests (C). Uptake, adherence, detection sensitivity and detection specificity are set to 4%, 50%, 80% and 92% respectively.
The present study has several significant results. First, although implementing portable sensors reduced the burden of infection by reducing the pool of infectious individuals, it largely depended on the specificity of the detection algorithm. Low detection specificity results in false-positive message about potential SARS-CoV-2 infection leading to unnecessary quarantines, thereby reducing the pool of susceptible individuals.
Without improvements in detection specificity, each user would, on average, spend two more days a month in unnecessary quarantine, and close to 40,000 to 65,000 additional laboratory-based tests per day would be required. In addition, the associated social and economic harm is likely to undermine public confidence in and adherence to a wearable-based pandemic mitigation strategy. Therefore, along with prioritizing the recording and compliance of wearables, their associated costs should be considered before implementation.
Balance between detection sensitivity and specificity. Prevented infections (A), reduction in the burden of infection (B), days incorrectly used in quarantine per. month per. unit user (C) and average daily demand for laboratory-based tests (D) over the entire simulation period, as a function of detection sensitivity and specificity. Gray boxes indicate nominal sensitivity (80%) and specificity (92%).
Another effective solution would be to include confirmatory antigen testing to increase the overall specificity of the strategy and decrease the overall false-positive rate. The introduction of RATs will reduce the number of days spent in quarantine by ~ 300 times, while bringing the further demand for laboratory-based testing infrastructure down to moderate levels. However, this would not 100% compensate for poor detection specificity.
With higher detection specificity, the authors noted a four-fold reduction in quarantine days per month per. user (misused by the user). They also observed a two-fold reduction in laboratory-based tests performed daily and a five-fold reduction in antigen tests used daily.
Overall, wearable implementation is more advantageous than broad antigen-test-based screening methods that require high production volumes, infrastructure, and financing; wearables detect non-invasive SARS-CoV-2 infections without active user engagement.
According to the authors, this is the first study that explored scenarios for implementing portable sensors as a COVID-19 mitigation strategy. The use of wearables will enable real-time detection of presymptomatic and asymptomatic SARS-CoV-2 infections. By complementing and supporting FTTI systems, their implementation will also reduce the burden of SARS-CoV-2 infections and help alleviate the pandemic.
However, in scenarios where the detection algorithm specificity was low, complementary interventions, such as RATs, potentially reduced false positives, minimizing costs and reducing the resource burden.
Future studies should explore better ways to incorporate portable sensors into FTTI pandemic control systems; and identify how these devices could continue to be used for public health benefits, complementary to vaccines, to inform future research investments and policies.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered essential, guide clinical practice / health-related behavior or be treated as established information.