Fig. 2: Three different isolation rules for different groups.

a Symptom-based rules. The vertical dotted lines mean the current symptom-based isolation guideline. The x-axis represents the additional isolation period from the current guideline. b Fixed-duration rules. The x-axis represents the fixed period of isolation. Left panels in both a and b show the risk of prematurely ending isolation for different isolation periods. The horizontal lines correspond to 5%. Estimated infectious period after ending isolation for different isolation periods (middle panels). The horizontal lines correspond to 1 day. The estimated period for which individuals are isolated unnecessarily after the end of their infectious period for different isolation periods (right panels). The squares and circles indicate the points with the lowest unnecessarily prolonged isolation period for which the following conditions are satisfied: i) the risk of prematurely ending isolation is lower than 5% and ii) the estimated infectious period after ending isolation is shorter than 1 day. The vertical dashed lines correspond to the optimal additional isolation period and the optimal fixed duration of isolation in the total group for symptom-based rules and fixed-duration rules, respectively. The solid lines and shaded regions in each panel indicate means and 95% confidence intervals, respectively. c Testing-based rules. The risk of prematurely ending isolation (first row of panels), the estimated infectious period after ending isolation (second row of panels), the estimated isolation period following the end of infectiousness (third row of panels), and the overall isolation period (fourth row of panels) are shown for different intervals between tests and numbers of consecutive tests indicating loss of infectiousness necessary to end isolation. PCR (polymerase chian reaction) tests (limit of detection \({{\boldsymbol{=}}}\) 2.9 log10 copies/ml) were used to measure viral load. The areas surrounded by solid lines are those with 5% or lower risk of prematurely ending isolation and with 1 day or shorter estimated infectious period after ending isolation, respectively. The triangles correspond to the points with the shortest estimated isolation period following the end of infectiousness for which both conditions noted above are satisfied. Color keys and symbols apply to all panels. Note that the estimated values are based on 100 independent simulations.