Table 6 Testing strategies to support exiting from lockdown: Findings from modelling studies

1

Switzerland

Muller et al. [45]

Daily random testing

• Daily random testing will reduce the delay between changes in policy and the observation of their effects

• Additional testing capacity of 15,000 per day carried out randomly would provide data about the evolution of the epidemic during exit.

2

UK

Panovska-Griffith et al. [46]

Active testing of symptomatic population

Increased levels of testing (between 59 and 87% of symptomatic people tested at some point during an active COVID-19 infection) and effective contact tracing and isolation for infected individuals can prevent rebound of the epidemic during reopening of schools and society in UK.

3

Mendoza, Argentina

Mayorga et al. [47]

Extensive testing capacity to detect asymptomatic individuals

Massive COVID-19 screening to detect around half of the asymptomatic and very mildly affected individuals would not need strict suppressive actions- if 45% of asymptomatic individuals are detected through testing and are isolated, there would not be a need for lockdown.

(This modelling exercise was undertaken with assumptions- a) imposing lockdown when ICU beds occupancy reaches 50%, and b) relaxing restrictions when this value reaches 30%)

4

India

Gupta et al. [17]

Increased testing

Lower restrictive measures along with increased testing during lockdown relaxation have the same effect as stricter physical distancing measures with lower levels of testing.

5

Italy

Li et al. [21]

Upscaling the testing capacity

• True number of infected cases and relative testing capacity are better determinants to guide lockdown exit strategies, compared to R.

• Testing capacity of at least 16 times the number of newly infected cases is required before considering exit at regional levels in Italy.

6

Australia

Lokuge et al. [54]

Community-based surveillance strategy using pooling of samples

• Exhaustive testing of patients with respiratory symptoms in the community is the most efficient and feasible means of detecting community transmission of COVID-19 during relaxation of measures.

• Pooling allows increased case detection when testing capacity is limited, even given reduced test sensitivity.

7

Italy

Pernice et al. [55]

Targeted testing in high-risk groups and contact tracing

• Contact tracing and targeted testing in high-risk groups would provide the same result as larger number of untargeted (or less targeted) tests.

• Targeted testing approach is more efficient and feasible.

8

NA

Bej et al. [56]

Pro-active testing (testing beyond those who show symptoms)

• Compared effects of different exit strategies with high/low levels of pro-active testing. Strategies that lack high levels of pro-active testing led to a second wave of infection.

9

USA

Tam et al. [57]

Expanding testing capacity and encouraging early testing

• Infection rate can be decreased by increasing the sum of testing rate and recovery rate of asymptomatic individuals, after lifting the stay-at-home orders.