Simulation suggests that rapid activation of social distancing can arrest epidemic development due to a novel strain of influenza

Table 2 Diagnosed case thresholds and intervention trigger timings

Threshold	Cases	R₀
		1.5	2.0	2.5	3.5
		Delay until threshold reached (days)
0.05%	15	9	7	6	5
0.1%	30	13	9	8	6
0.5%	150	24	16	13	10
1.0%	300	30	19	15	11
2.0%	600	37	23	18	13
4.0%	1200	46	27	21	15
8.0%	2400	58	32	24	17

This table shows a range of case count trigger thresholds and the consequent delay in intervention corresponding to each threshold. The boldface delays are those for which the final illness attack rate is < 10%, if all four intervention measures are activated at that time and continued indefinitely.
For a case to count towards the intervention threshold it is assumed that the following sequence of events occurs:
a) The individual becomes infected.
b) The individual experiences symptomatic infection.
c) They present to a health care professional in a monitoring scheme.
d) The infection is correctly diagnosed as pandemic influenza.
e) The case is reported to the monitoring scheme.
We assume a 50% ascertainment efficiency, which is the conditional probability that e) occurs, given that both a) and b) have occurred. We assume that there are no false-positive reports of pandemic influenza.

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