Before revision:  However, this control is lost once case numbers overwhelm the limited TTI capacity. Beyond that tipping point , increasingly more infectious individuals remain undetected, generating a self-accelerating spread .
After revision:  However, this equilibrium is endangered (i) if contact restrictions are relaxed, or (ii) if case numbers grow too high. The latter destabilisation marks a novel tipping point beyond which the spread self-accelerates because test-trace-and-isolate capacities are overwhelmed .