Starting in mid-May 2020, many US states began relaxing social-distancing measures that were put in place to mitigate the spread of COVID-19. To evaluate the impact of relaxation of restrictions on COVID-19 dynamics and control, we developed a transmission dynamic model and calibrated it to US state-level COVID-19 cases and deaths. We used this model to evaluate the impact of social distancing, testing and contact tracing on the COVID-19 epidemic in each state. As of 22 July 2020, we found that only three states were on track to curtail their epidemic curve. Thirty-nine states and the District of Columbia may have to double their testing and/or tracing rates and/or rolling back reopening by 25%, while eight states require an even greater measure of combined testing, tracing and distancing. Increased testing and contact-tracing capacity is paramount for mitigating the recent large-scale increases in US cases and deaths.

从 2020 年 5 月中旬开始，美国许多州开始放松为减缓 COVID-19 传播而采取的社交距离措施。为了评估放宽限制对 COVID-19 动态和控制的影响，我们开发了一个传播动态模型，并根据美国州级 COVID-19 病例和死亡情况对其进行了校准。我们使用这个模型来评估社交距离、检测和接触者追踪对每个州的 COVID-19 疫情的影响。截至 2020 年 7 月 22 日，我们发现只有三个州有望遏制疫情曲线。39 个州和哥伦比亚特区可能必须将检测和/或追踪率提高一倍和/或将重新开放时间推迟 25%，而 8 个州则需要采取更大的综合检测、追踪和疏远措施。提高检测和接触者追踪能力对于缓解美国近期病例和死亡人数的大规模增加至关重要。