COVID-19 disease modelling

David Posnett — Sat, 14 Mar 2020 00:02:57 +0000

Excellent article in the NY Times:

Worst-Case Estimates for U.S. Coronavirus Deaths

March 13, 2020Updated 5:02 p.m. ET

Projections based on C.D.C. scenarios show a potentially vast toll. But those numbers don’t account for interventions now underway.

One of the CDC’s top disease modelers, Matthew Biggerstaff, presented four possible scenarios — A, B, C and D — based on characteristics of the virus, including estimates of how transmissible it is and the severity of the illness it can cause…. Highlights:

Between 160 million and 214 million people in the United States could be infected over the course of the epidemic, according to one projection….
The pandemic could last months or even over a year, …
As many as 200,000 to 1.7 million people could die worldwide…
2.4 million to 21 million people in the United States could require hospitalization, potentially crushing the nation’s medical system, which has only about 925,000 staffed hospital beds. Fewer than a tenth of those are for people who are critically ill…
Studies of previous epidemics have shown that the longer officials waited to encourage people to distance and protect themselves, the less useful those measures were in saving lives and preventing infections.
Even severe flu seasons stress the nation’s hospitals to the point of setting up tents in parking lots and keeping people for days in emergency rooms. Coronavirus is likely to cause five to 10 times that burden of disease…
A preliminary study released on Wednesday by the Institute for Disease Modeling projected that in the Seattle area, enhancing social distancing — limiting contact with groups of people — by 75 percent could reduce deaths caused by infections acquired in the next month from 400 to 30 in the region.
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,” …
During the Spanish Flu 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.” The mayor of St. Louis quickly took that advice, closing for several weeks “theaters, moving picture shows, schools, pool and billiard halls, Sunday schools, cabarets, lodges, societies, public funerals, open-air meetings, dance halls and conventions until further notice.” The death rate rose, but stayed relatively flat over that autumn.

By contrast, Philadelphia took none of those measures; the epidemic there had started before Dr. Blue’s warning. Its death rate skyrocketed.

disease modeling – R&R – Reachout and Rebuild

COVID-19 disease modelling