This paper describes computer modeling of epidemic control through contact tracing and isolation. I’m attaching the tweetstream from one of the authors, @RozEggo, below which explains the findings.
Can isolation and contact tracing control outbreaks of 2019-nCoV? Our new model determines under which scenarios it may work and what % of contacts need to be be traced.
For successful epidemic control, under the most optimistic conditions, 80 % of symptomatic contacts would have to be traced and isolated to control 80 % of outbreaks. In the real world, every symptomatic contact might not be isolated successfully or in time, or the disease might be transmissible by asymptomatic carriers for a long period of time.
This graphic from Latest Insights | Prevent Epidemics describes where this fits into an overall response (used for educational, non-commercial purpose):
Reference
Hellewell J, Abbott S, Gimma A, Bosse NI, Jarvis CI, Russell TW, et al. Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Lancet Glob Heal [Internet]. 2020 Apr;8(4):e488–96. Available from: https://linkinghub.elsevier.com/retrieve/pii/S2214109X20300747