Four factors that lead to coronavirus spread
The United States recently passed the grim benchmarks of 200,000 COVID deaths and 7,000,000 cases — both of which are the highest figures in the world by significant margins, although if current trends continue, India will pass the U.S. in total number of cases sometime this fall.
The dramatic American COVID numbers invite comparisons with other countries — hence, ubiquitous articles by pundits on why can’t we be more like South Korea, what we could have learned from Germany, or if we should have managed the pandemic like Sweden (including a recent exchange on the floor of the Senate between Dr. Anthony Fauci and Sen. Rand Paul on whether the U.S. and Sweden can be compared.
These arguments are superficially appealing. However, most people, from senators to epidemiologists to journalists, fail to appreciate that the United States has a unique profile in terms of several basic characteristics that help determine whether or not an outbreak will occur.
In truth, the United States is not directly comparable to any single country, and it is difficult to draw firm conclusions about the American response, good or bad, based on what has occurred elsewhere in the world.
Here are four factors that are crucial to the likelihood of COVID spread. They are certainly not the only four factors, nor are they absolutely determinant.
There are definitely many other causes, some known, some unknown. And there is some overlap between them — admittedly they are not completely independent variables. But each of thesematters in its own way in terms of viral spread.
Population: Basically more people, more potential hosts for the virus, more possible cases. The U.S. has the third highest population in the world. Of the eight countries with themost COVID cases, five are among the top 10 most populous countries in the world (U.S., India, Brazil, Russia and Mexico, and that doesn’t include China because we may not be able to trust their real COVID figures). In the U.S., population matters as well — seven of the top 10 most populous states are among the top ten in COVID cases (California, Texas, Florida, New York, Illinois, Georgia, North Carolina).
Size of the country: COVID is basically a regional disease. As such, it is harder to eradicate viral spread nationwide in a larger country because new outbreaks can come from anywhere. The US is fourth in the world in land mass. Five of the world’s top ten countries by area are also in the top ten by COVID cases (US, India, Brazil, Russia and Argentina).
Mobility: The more people travel, the more likely the spread of the virus. Mobility is hard to measure directly, but according to the Washington Post, the U.S. is the number one country in the world in terms of domestic mobility and travel. (At the outbreak of the pandemic, the U.S. was also third in receiving international tourists, just behind France and Spain, two of the most heavily affected countries by COVID in the world).
Diversity: There is unquestionably a genetic component to viral spread. A more diverse country will have a greater chance that some of its population will demonstrate resistance to infection, and there will also be a greater number of susceptible people with less immunity. Like mobility, diversity can be difficult to measure, but according to the Pew Research Center, the U.S. is more diverse than most Western European or Asian countries but less diverse than Canada, Brazil, Mexico or most African countries.
In summary, the United States is at or near the top of the world in population, area, and mobility, and more diverse than most industrialized countries. No other country has a similar profile.
The country that is closest to the United States is Brazil: fifth in area, seventh in population, more diverse but less mobile. Brazil, not coincidentally, has over four million COVID cases, the third largest number in the world, and virtually the same per capita case and death totals as the United States.
Canada, which is frequently compared to the U.S., has a far smaller number of COVID cases. But Canada is ranked 39th in the world by population and while it has a greater area than the U.S., 80-85 percent of its population lives within 100 miles of the U.S. border; the vast majority of the Canadian land mass is either uninhabited or sparsely populated so containment of the virus is easier.
None of this is meant as either a defense or a criticism of the current administration and its COVID advisers.
For those who want to see Donald Trump lose the coming election, the case and death numbers, with the U.S. as the world leader, provide a convenient opportunity to make the claim he has done an especially egregious job of handling the pandemic.
But just as Newton’s Third Law of Motion predicts, for every action there is an equal and opposite reaction — in this case by Trump’s defenders who point out limitations in these numbers.
All in all, this amounts to an unresolvable argument, basically a political food fight worthy of the cafeteria in the movie “Animal House.”