Much of the world has virtually shut down in response to the coronavirus pandemic. But a few countries have taken a different course. Presented below are the “attack rates” for countries that different approaches to this disease. I’ve defined “attack rate” as the percent of the population that has been diagnosed with COVID-19 up to today. Problems with making this diagnosis are also discussed.
Bernard Baruch explained that he had exited the stock market before the 1929 crash when even his shoeshine boy was dispensing investment advice. Today medical advice about how we should treat COVID-19 is coming from anyone who can put the 26 letters of the alphabet in the proper sequence. Even Kim Komando is handing it out. Be assured that almost all of it is misinformed and wrong.
My home county is using RT- PCR to test for the virus. The CDC’s instruction for the use of this test is appended at end of this article. If you go to page 39 you’ll find this: FDA Sensitivity Evaluation: The analytical sensitivity of the test will be further assessed by evaluating an FDA- recommended reference material using an FDA developed protocol if applicable and/or when available. I’ll assume the sensitivity is 95%. The test is very unlikely to have a sensitivity much higher than 95%.
As I’ve mentioned before, a positive test is a true positive only when you know both the sensitivity and prevalence of what you are testing. Consider the case of the USS Theodore Roosevelt. About 4,000 sailors were aboard. I don’t know why some or all of them were tested for COVID-19. But they were mostly young and in good health. Assume none of them had the virus. If a test 95% sensitive were used and all were disease free, 200 would still test positive – 5% of 4,000 – which is about the number of positive tests observed on the vessel’s crew. If 50% of the sailors were infected then a positive test would have a 95% chance of being a true positive. As there were only a few hundred positive tests on the ship the chance of false positives is very high. The WHO’s advice to “Test, test, test” is poorly reasoned. Only high risk subjects should be tested so as to minimize the problem of false positives.
Here is a list of the percentage of populations diagnosed with COVID-19 as of April 3:
- US 0.07
- Sweden 0.06
- Norway 0.09
- Denmark 0.10
- Netherlands 0.09
- Belgium 0.14
- South Korea 0.02
- Japan 0.002
You are likely aware that these countries have used different strategies to deal with the virus. The US has shut down all but the most important activities. The Swedes have limited gathering to no more than 50 people – initially 500. Just about everything is open. Their Scandinavian counterparts have adopted an approach similar to the US. Thus far, their case load is not less than Sweden’s. The US also has a rate no lower than that of Sweden.
The Netherlands has also not shut down. They have advised sensible preventative measures, but they remain open. Compare their “attack rate” to neighboring Belgium, a country similar in size and culture. I’m not assigning any statistical significance to any of these differences, but the Netherlands doesn’t have a higher rate than Belgium
Similarly, the countries with the lowest rates – South Korea and Japan have also not shut down. They are countries that have long routinely used masks – especially Japan. They have traced contacts and advised behavior appropriate for a highly contagious epidemic. Japan, an island nation has imposed strict limits on the entry of foreigners.
Of course, the disease could pivot and get worse in countries that remain open, but these observations suggest that when all this havoc is over we may wonder why we acted with such force. Could we have handled this disease in an effective way, but one less damaging to the well being of our country’s infrastructure, institutions, and the material benefit of its population?