The focus and timing of COVID-19 pandemic control measures under healthcare resource constraints

Chen Wei; Zhengyang Wang; Zhichao Liang; Quanying Liu

Our model allowed retrospective analyses and counterfactual reasoning on Wuhan's control policies. Wuhan's strategy to proactively isolate all suspected cases, effectively removed patients from the infectious pool; otherwise waiting for confirmation would lead to heavier reliance on the laboratory testing capacity and thus leaving more infectious cases in the community. Serving as a buffer between the symptomatic cohort and the confirmed cohort, Wuhan's strategy bought extra time for the culmination of medical resources in all departments, including extra-provincial medical staff dispatch, test kit production and new hospital construction. Our model showed that such a strategy in Wuhan was implemented soon enough (6 days until the advantage diminished) to provide a relieved NPI strength required for suppression. Moreover, proactive isolation in Wuhan was also beneficial in reducing peak hospital bed occupancy (from 44,000 to 40,710). As long as the transmission control had been strong enough, such positive outcomes would have been warranted regardless of the timing of NPI. However, if control measures had not been sufficiently strong to suppress the outbreak, isolating all suspected cases would have had a negative outcome due to imposing extra stress on the healthcare system.