Table 2.

Cumulative infectivity of a traced contact prior to isolation and percentage of infections averted by isolation under two transmission scenarios

Days from index case specimen collection to contact isolation	Cumulative infectivity prior to isolation (%)	% of infections averted (R0 = 0.95)	% of infections averted (R0 = 1.2)
0	20.6	54 (42–66)	65 (53–70)
1	31.8	51 (39–63)	59 (48–65)
2	44.9	47 (35–59)	53 (42–58)
3	58.9	43 (31–54)	47 (35–53)
4	72.5	41 (29–52)	43 (33–49)
5	84.4	39 (28–51)	40 (32–47)

Two transmission scenarios: R₀ = 0.95 and R₀ = 1.2. Estimates assume a 40% detection rate for symptomatic cases, a 2-day lag between symptom onset and specimen collection from the index case, and a 50% contact tracing success rate. Values are medians and IQRs from 200 simulations.