评论—Regarding Relaxation of COVID-19 Pandemic Precautions
At his news conference on Sunday, March 29, President Trump backed off his earlier goal of relaxing restrictions and going back to work by Easter (April 12); he said that the White House’s social distancing guidelines of avoiding nonessential travel, not going to work, not eating at bars and restaurants, and not gathering in groups of more than 10 will be extended until April 30 and perhaps until June.
Stay-at-home guidelines have been instituted at a U.S. state level starting in California on March 19, and within a few days in more than half the states and the Navajo Nation, with many cities and counties in 13 additional states joining in. However, 11 states have no stay-at-home guidelines at this time. The result is an uneven mix of local and state directives for “shelter in place,” or “safer at home”, but at least 229 million people (almost 70% of the population) in 26 states, 66 counties,14 cities, and one territory have been urged to stay at home according totheNew York Times(https://www.nytimes.com/interactive/2020/us/coronavirus-stay-at-home -order.html.）。
As we continue to significantly restrict business and personal activities throughout the world, the general public and elected officials have naturally started to question how long these restrictions should continue.许多意见已经表达了许多意见，通常更多地基于个人的愿望恢复正常生活而不是证据和声音流行病学推理。However, premature relaxation of restriction would be disastrous.那么我们应该如何基于感染控制决策？
Having few or no people with transmissible infection is the most obvious component. Although a goal of NO cases is theoretically ideal, it is unrealistic on a practical level. A recent (3/29/20) possible standard was published byDr. Scott Gottlieb and colleagues and美国企业研究所（https://www.aei.org/research-products/report/national-coronavirus-response-a-road-map-to -reopening/）建议a number of factors, including having a14天的每日下降案件数量;当地医院能够安全地治疗all patients requiring hospitalization without resorting to crisis standards of care; and the state having the capacity to test all people with COVID-19 symptoms and conduct active monitoring of all confirmed cases and their contacts.但是，无论最终标准如何，必须认识到它的无零发病率可传染性感染in a region with a significant number of susceptible people意味着当通过公共卫生措施无拘无束的病毒复制时，该区域仍然存在几何增加的风险。
- 最大限度地减少运动intothe newly-relaxed area by people from higher-risk areas
- 最大限度地减少运动出去of the relaxed area into higher-risk areas from which people could return with infection
Movement control is particularly challenging in the U.S. because current planning discussions are based on the artificial administrative boundaries of town, city, county, and state rather than the natural regions within which we travel and interact as determined by our social/commercial networks.The normal tight interconnection between neighboring communities or cities and their suburbs means relaxing one but not the other would be a significant challenge to enforce and monitor. Planning that defines a region by taking into account the normal human traffic patterns within a region is more likely to be safe and successful.
Because there will be a non-zero incidence of cases in any relaxed-restriction area and because complete interdiction (voluntary or otherwise) of all traffic between higher- and lower-risk areas is not likely, the identified case rate and transmission rate within an area deemed “low-risk” is only a snapshot in time that must constantly be reevaluated通过持续监测.
因此，from the above it is clear that relaxation of social distancing and reopening of normal business activity cannot be done safely without first doing
- WIDESPREAD testing within the region in which relaxation of standards is considered in order to reliably identify disease incidence and transmission rate
因此，in order to safely relax generalized social distancing precautions within an area, we need to
- 扩展测试以包括具有广泛症状和症状的患者，including those with mild or no symptoms
- 聘请大量人员进行测试，跟踪案例和监视器isolation and quarantine adherence
Rapid point-of-care testing is important because self-directed isolation is less likely to be adhered to when there is only assumption of possible illness rather than a test-based diagnosis and because contact identification and tracing can begin immediately without having to track a patient down days later. Some countries have had success using apps to monitor and communicate with positive cases.
For adults over age 60, those with underlying health conditions, and others at heightened risk from COVID-19, physical distancing measures and limitations on gatherings may need to be maintained until drugs or vaccines become available.