Sunday, April 19, 2020

COVID-9 Prophylaxes: Geographic Location

I provide my introduction to this COVID-9 Prophylaxes series in my magnum postus. Here I began detailing the results of my observational studies. Be aware that we are in search of one or more COVID-9 prophylaxes. In other, less suggestive words, were are in search of preventative measures to keep us from becoming infected.

Using my august magnum databasus, I analyzed the per capita infections of 191 countries. Though I have 208 countries in my database, I exclude from my analysis those 17 countries with fewer than 50,000 residents. Those small countries (in population, not necessarily in size) show extreme variations in per capita infection rates; some are extremely high and some extremely low. Rightly or wrongly, I attributed those extremes to the problem of small sample size, and I thereby excluded them without further study.

I obtained death and infection numbers for each country from the now world-O-famous worldOmeter site. I updated those numbers not long before writing this post. They are current as of 13 April 2020.

I obtained the population for each country from a different worldOmeter web site.

Since I'll be reporting infections per million people on a country by country basis, those two sets of data are all I need to get started. I will identify my other sources of data as appropriate.

I'll be reporting potential prophylaxes based on their Prophylactic Index, which I cleverly abbreviate as PI. The Prophylactic Index is a term I simply made up. It allows me to score potential prophylaxes by a single number. The PI is simply the ratio of two infection rates. More specifically:

PI = infections per million of control group / infections per million of potential prophylactic group.

The larger the PI, the more effective the potential prophylactic might be. As a hypothetical example, presume that one country with Possible Prophylactic #1 has 100 infections per million while every other country in the group has 1000 infections per million. In that hypothetical, PI = 100 / 10 = 10. In other words, the data suggests that Possible Prophylactic #1 residents will suffer 10 times fewer infections than everyone else, everything else being equal. Alternatively, those who do not (or cannot) take advantage of Potential Prophylactic #1 are 10 times more likely to contract the virus, everything else being equal.

With that dreadfully boring explanation now in hand, you get your first peek at the results of my observational study. It shows the prophylactic effect of living at various latitudes. Here we go:

Tropics (81): 6.1
South of Tropics (20): 5.3
North of Tropics (90): 0.1

Holy Cow!

To understand my feigned amazement, I offer the following, thrilling descriptive narrative. The number within the parentheses represents the number of countries in the potential prophylactic group. Using the Tropics as an example, the study compared the 81 tropical countries against the remaining 170 countries in the study. The non-weighted average infection rate for the 170 non-tropical countries was 6.1 times greater than the non-weighted average infection rate for the 170 tropical countries. The PI (prophylactic index) for living in the tropics is therefore 6.1.

With that shorthand in hand, we can move much more quickly.

Looking at the latitude results reveals that those of us living north of the tropics are 10 times more likely to become infected than are those living south of us. It's not immediately clear why that should be so, but that's what the data say.

One possibility, which we will consider carefully beginning with the next post, is that the apparent latitude effect is actually some sort of weather effect. Lots of smart people north of the tropics are arguing that the virus will abate when the summer arrives, due to increased temperature and humidity. Previous flu seasons, after all, tended to abate in the summer months. Why should the COVID-19 virus behave any differently?

If they be correct, those smart people living north of the tropics, then we can expect that the results will flip come northern hemisphere summer, which will also become southern hemisphere winter. Then the northern hemisphere folks will be only 1/10th as likely to contract the infection as their southern hemisphere antipodes.

I know what's coming in the next few posts though, and I fear that the smart NL folks might be in for a rude awakening.

I'll spend the remainder of this post summarizing the PI values for each geographic region on earth, excluding the arctic and antarctic. I'll allow you to begin speculating on what the results might mean.

Africa (55): 14.1
Oceania (6): 3.3
Latin America (20): 3.1
Asia (47): 2.6
Caribbean (17): 2.0
North America (4): 0.5
Europe (42): 0.1

Finally, Africa gets a break.

North America and Europe take it in the neck.