Skip to main content
. 2021 Mar 23;372(6542):635–641. doi: 10.1126/science.abf9648

Fig. 3. Simulated relative effectiveness of the extended contact-reducing measures and the mass testing.

Fig. 3

(A) The change in observed prevalence of infectious nonquarantining individuals between 10 and 65 years of age as predicted by the microsimulation model. For comparison, the observed test-positivity rate is shown in blue. The facets show changes (left) from the pilot to the first round of mass testing and (right) from the pilot to the second round of mass testing. Shown scenarios compare the effect of (top to bottom) no additional interventions that limit the growth rate of reproduction number (Re) = 1.4, the extended contact-reduction measures drastically reducing the growth rate to Re = 0.6 and no mass testing being conducted, the extended contact-reduction measures reducing the growth rate to Re = 1.0 and no mass testing being conducted, no change in growth rate but mass testing, and the extended contact reduction measures reducing the growth rate to Re = 1 and mass testing. In scenarios without mass testing, we compared prevalence of infectious individuals on the same days as testing occurred in scenarios with mass testing. CIs around the modeled values in each scenario are calculated as the 2.5 and 97.5% percentiles across 500 model iterations, with the point estimate representing the median. The CI around the observed value is its binomial CI. (B) Simulated infection incidence of alternative intervention strategies. Simulations are aligned by the date of the first mass test [time (t) = 0]. The dashed line indicates the timing of the extended contact-reducing measures, and the solid lines indicate the timing of the mass testing campaigns. Colors indicate the simulations stratified into whether no mass testing or one, two, or three testing rounds were performed and the effectiveness of the extended contact-reduction measures on the growth rate. Red and yellow diamonds indicate the prevalence of infectiousness observed among the tested nonquarantining age-eligible population, corresponding to the scenarios in (A).