A recent paper, cited by Dr. Fauci at a news briefing on Tuesday, concludes that the rapid and aggressive quarantine and social distancing measures applied by China in cities outside of the outbreak’s epicenter achieved success. “Most countries only attempt social distancing and hygiene interventions when widespread transmission is apparent. This gives the virus many weeks to spread,” the paper said, with the average number of people each new patient infects higher than if the measures were in place much earlier, even before the virus is detected in the community.
“By the time you have a death in the community, you have a lot of cases already,” said Dr. Mecher. “It’s giving you insight into where the epidemic was, not where it is, when you have something fast moving.” He added: “Think starlight. That light isn’t from now, it’s from however long it took to get here.”
He said a single targeted step — a school closing, or a limit on mass gatherings — cannot stop an outbreak on its own. But as with Swiss cheese, layering them together can be effective.
This conclusion is backed up by history.
The most lethal pandemic to hit the United States was the 1918 Spanish flu, which was responsible for about 675,000 American deaths, according to estimates cited by the C.D.C.
The Institute for Disease Modeling calculated that the new coronavirus is roughly equally transmissible as the 1918 flu, and just slightly less clinically severe, and it is higher in both transmissibility and severity compared with all other flu viruses in the past century.
Dr. Mecher and other researchers studied deaths during that pandemic a century ago, comparing the experiences of various cities, including what were then America’s third- and fourth-largest, Philadelphia and St Louis. In October of that year Dr. Rupert Blue, America’s surgeon general, urged local authorities to “close all public gathering places if their community is threatened with the epidemic,” such as schools, churches, and theaters. “There is no way to put a nationwide closing order into effect,” he wrote, “as this is a matter which is up to the individual communities.”