Philip Greenspun’s Weblog

Apologies for the macabre subject, but with everyone freaking out about the coronavirus, I’m wondering if it makes sense to step back and ask why the Diamond Princess wasn’t a worst-case scenario. The ship held 3,700 people. The virus spread all around the ship before anyone knew what was going on. Then everyone on board was kept on board, all breathing from the same ventilation system, eating food from the same kitchen (almost surely prepared by at least some workers who had the virus, but didn’t know it). Out of 3,700 passengers and crew, 6 have died (Business Insider).

That’s a death rate of 1/6th of 1 percent (0.16 percent), and concentrated among people whose immune systems were weakened due to other factors (i.e., people who might have died a year later from the flu).

The U.S. overall is not more crowded than a cruise ship. Why should we expect more than 0.16 percent of Americans to die when this is all over? That’s unfortunate, of course, and a huge number when multiplied by 330 million: 535,000. But it is not an economy-ending or country-ending number. And, since our country is not in fact as densely populated as a cruise ship, the real number might be far less than this upper bound. It might be closer to the 80,000 who died from the flu in 2017-2018 (source). And there might not be that many additional deaths because the same people who get killed by the flu are also susceptible to COVID-19.

One factor that could explain how the death rate could be higher: as the disease spreads, hospitals and other health care resources will be spread thin. But, on the other hand, knowledge about how to treat the infection will improve. If these two factors cancel out, we’re back to the Diamond Princess being the worst-case scenario. Finally, consider that the cruise ship demographic is older and more fragile than the general population.

Related:

• “The Strongest Evidence Yet That America Is Botching Coronavirus Testing” (Atlantic): “I don’t know what went wrong,” a former CDC chief told The Atlantic.
• “Why the CDC botched its coronavirus testing” (Technology Review): The first testing kits from the Centers for Disease Control had a simple fault, and red tape prevented other labs from creating their own.

The Black Death: The World’s Most Devastating Plague” by Dorsey Armstrong, a professor at Purdue, talks about places that were spared from most of the waves of plague that swept through Europe starting in 1348.

If we don’t want to die from coronavirus, what can we do?

Iceland was an example of a place that escaped plague for more than 50 years. It took a long time to reach Iceland by ship so asymptomatic carriers of the plague couldn’t walk off into port in Iceland. More likely they, and all of their crewmates, would die before reaching Iceland.

People today travel by plane, however, which is nearly instantaneous. So the “far away by ship” advantage does not seem likely to be realized by any country today.

Finland remained substantially plague-free, says the author, despite having land borders with Sweden, Norway, and Russia, as well as being integrated into the sea trading network of the time that had spread the disease so quickly throughout the Mediterranean and to the British Isles. The secret in Finland was low population density.

Wikipedia says, regarding the influenza pandemic of 1918: “In the U.S., about 28% of the population of 105 million became infected, and 500,000 to 675,000 died (0.48 to 0.64 percent of the population).” Our population is more than 3X the 1918 level and therefore our population density is more than 3X the 1918 level. So the Finland trick cannot work for Americans in general. But maybe for an individual American it could. Move to a non-urban area of a spread-out state, e.g., Alaska or Wyoming. Follow Barbra Streisand and the rest of the Hollywood #Resist crowd to Canada (or pick a different low-density country, such as Argentina).

The professor says that governments that shut down or severely restricted links to the outside world ended up saving most of their citizens and/or subjects. So maybe North Korea or a similarly restricted nation will be comparatively safe?

The professor says that cities with good sanitation did not escape the plague, but death rates were lower. So Japan and Switzerland might have fewer cases of coronavirus? “Mortality burden of the 1918–1919 influenza pandemic in Europe” says that Switzerland was not significantly different from France (but sparsely populated Finland suffered only half the death rate).

Integrating what we know from the Black Death and present-day statistics and conditions, Iceland and New Zealand seem like the most obvious places to run for a re-enactment of the Decameron. They’re islands. They have lower population densities than the U.S. They have comfortably high living standards. However, we need to cross Iceland off the list due to the fact that it operates an international airline hub. People from more than 50 different countries might show up on a typical evening. That leaves… New Zealand.

Fun fact: We get the word “quarantine” from the Venetian government’s requirement that ships coming into Dubrovnik wait at a nearby island for 40 days before coming into contact with the townspeople.

At least we’ll never have to worry about plague per se, again, right? Actually… the bacterium has evolved antibiotic resistance in Madagascar (CDC) and the fleas that carry it have evolved insecticide resistance.