2020年经济学人 美国新冠肺炎激增(2)（在线收听）

Doug Ducey, the Republican governor of Arizona, began reopening his state in early May, when there were around 400 new cases being detected a day. He began backtracking two months later, after caseloads had swollen tenfold, to around 4,000 a day, and 90% of the intensive-care beds in the state were occupied. Mr Ducey, like many Republican governors, had also barred cities in his state from imposing their own mask-wearing requirements, only reversing himself on June 17th.

亚利桑那州共和党州长道格·杜西5月初开始重新开放该州，当时每天查出大约400起新增病例。两个月后，他改变了声明，当时的病例数量增加了10倍，达到每天4000个左右，而且该州90%的重症监护床位都被占用了。和许多共和党州长一样，杜西先生也禁止他所在州的城市实施强制佩戴口罩要求，直到6月17日他才改变了主意。

Nor was there much desire for caution from the White House. Vice-President Mike Pence wrote an op-ed for the Wall Street Journal on June 16th with the headline “There Isn’t a Coronavirus ‘Second Wave’”, arguing that “the media has tried to scare the American people every step of the way, and these grim predictions of a second wave are no different.” A key argument of Mr Pence and President Donald Trump, even as case counts were rising through June, was that this was an artefact of increased testing and that the death rates continued to decline. Though the first contention was questionable (the rate of increase in cases exceeded the rate of increase in tests), the second was true.

白宫对此也没有非常谨慎。美国副总统彭斯6月16日为《华尔街日报》写了一篇专栏文章，标题是“冠状病不会爆发‘第二波’”，他认为“媒体一步一步地试图吓唬美国人民，而这些对第二波疫情浪潮的严峻预测也没什么不同。”彭斯先生和唐纳德·特朗普总统的一个关键论点是，尽管6月份的病例数一直在上升，但美国扩大了检测，这是人为造成的，还有死亡率会继续下降。尽管第一个论点值得怀疑（案例的增长率超过了测试的增长率），但第二个论点是正确的。

That puzzle—why deaths remain flat while cases have begun another exponential rise—can be explained by four factors. First, the substantial increase in testing means that more cases will be detected. Second, evidence suggests that younger adults are behind the latest surge in the virus. In Florida the median age of covid-19 patients has dropped from 65 to near 40. Third, there is usually a lag of several weeks between a patient contracting the illness and when the patient’s death is reported to state authorities. Fourth, doctors seem to have become better at treating severe cases of covid-19, reducing the death rate even for those who must be hospitalised.

为什么死亡人数持平，而病例又开始呈指数上升，这一谜团可以用四个因素来解释。首先，检测的大幅增加意味着将发现更多的病例。其次，有证据表明，年轻人是最近病毒激增的幕后黑手。在佛罗里达州，新冠肺炎患者的平均年龄已从65岁下降到近40岁。第三，从病人感染疾病到向国家当局报告病人死亡之间通常有几个星期的时间间隔。第四，医生似乎更擅长治疗新冠肺炎重症病例，甚至降低了那些必须住院的患者的死亡率。