Assessing the feasibility and effectiveness of household-pooled universal testing to control COVID-19 epidemics

Abstract

Outbreaks of SARS-CoV-2 are threatening the health care systems of several countries around the world. The initial control of SARS-CoV-2 epidemics relied on non-pharmaceutical interventions, such as social distancing, teleworking, mouth masks and contact tracing. However, as pre-symptomatic transmission remains an important driver of the epidemic, contact tracing efforts struggle to fully control SARS-CoV-2 epidemics. Therefore, in this work, we investigate to what extent the use of universal testing, i.e., an approach in which we screen the entire population, can be utilized to mitigate this epidemic. To this end, we rely on PCR test pooling of individuals that belong to the same households, to allow for a universal testing procedure that is feasible with the limited testing capacity. We evaluate two isolation strategies: on the one hand pool isolation, where we isolate all individuals that belong to a positive PCR test pool, and on the other hand individual isolation, where we determine which of the individuals that belong to the positive PCR pool are positive, through an additional testing step. We evaluate this universal testing approach in the STRIDE individual-based epidemiological model in the context of the Belgian COVID-19 epidemic. As the organisation of universal testing will be challenging, we discuss the different aspects related to sample extraction and PCR testing, to demonstrate the feasibility of universal testing when a decentralized testing approach is used. We show through simulation, that weekly universal testing is able to control the epidemic, even when many of the contact reductions are relieved. Finally, our model shows that the use of universal testing in combination with stringent contact reductions could be considered as a strategy to eradicate the virus.

Pooled testing for SARS-CoV-2, options for efficiency at scale

“…Households or groups of several households have been encouraged to limit their contact with others during the pandemic to reduce the number of close contacts of any individual and hence the risk of transmission. A study that simulated pooling of households and the social interactions between them concluded that the whole Belgian population of 11 million individuals could be tested within 4 weeks, 38 similar to the achievement of Chinese health authorities in screening the 11 million residents of Wuhan province in 2 weeks in 2020. 4 …”

Optimizing and evaluating PCR-based pooled screening during COVID-19 pandemics

“…A recent review of scaling testing highlighted the role of population screening in combating the COVID-19 pandemic 1 . Compared to the Dorfman pooling, more sophisticated testing algorithms that may be more efficient have been proposed in the literature, including hypercube pooling testing 7 , non-random pool allocations 8 , multi-stage hierarchical pool testing 9 , and combinatorial non-hierarchical pool testing 10 , 11 . However, such sophisticated testing algorithms can be difficult to implement, especially in population screening.…”

“…Although the literature on Dorfman pooling and antigen testing has grown rapidly, the cost-effectiveness of different testing technologies and strategies under fast-changing epidemic dynamics remains unclear. Within the framework of simple Dorfman pooling, most recent studies have focused on the optimal design of pool size, modifications of the pooling workflows, and corresponding laboratory validation 7 , 8 , 10 , 12 – 16 . The efficiency, accuracy 7 , 12 , 14 , and cost-effectiveness 17 of pooled testing were evaluated under a set of static points of prevalence.…”

“…The efficiency, accuracy 7 , 12 , 14 , and cost-effectiveness 17 of pooled testing were evaluated under a set of static points of prevalence. These studies often assumed a fixed value for test sensitivity in their models, but experimental studies showed that pool size and prevalence had significant impacts on test sensitivity in many pooled algorithms 7 , 8 , 14 , 18 – 28 . Braul et al 29 and Cleary et al 10 bridged this gap by considering diluted sensitivities and viral load kinetics of SARS-CoV-2.…”

“…Digital technologies were proposed to enhance the effectiveness of population screening 39 – 47 . Studies also revealed that repeated PCR testing, antigen testing, and household-pooled testing could effectively suppress outbreaks 6 , 8 , 48 , 49 .…”