2020-03-29

Coronavirus Overblown? Look at Some Numbers

When coronavirus first came out, we didn't know much about the virus itself. It was clearly an economic threat though, if countries followed China's example. Whether justified or not, on an individual level it made sense to anticipate a big hit. As I put it, look at how people react to the flu each year, the media hypes it and pushes everyone to get vaccinated. The early data on coronavirus said there would be a freakout. It happened.

The media and health authorities ignored the risk. The CDC wasn't looking for community spread until late February. It was only looking for China travel links until then. Media and various political figures called travel bans racist. They said masks don't work. Health authorities said masks don't work. The globalized supply chain was hit and many people learned their nation, including the supposedly power U.S. economy, couldn't produce masks or basic medicines. Then these same media and health authorities swung into panic mode and ordered China-style lockdowns in the United States. At the same time, "the mainstream" learned about the virus. Average people (and especially journalists and even doctors when it comes to statistics) are horrible at math. Insane figures were going around that projected absurd death totals. They didn't take into account that quarantine measures slow the spread, but even without quarantine, some numbers were nuts. Even Fauci is out there claiming 100,000 to 200,000 deaths now. I expect that total could be hit when this virus infects the whole population, assuming no precautions or treatments. The death rate is almost always highest to start because a novel virus has no known treatment and there is no immunity to it.

Christopher Blading runs through the numbers in a new post. The tl;dr is the R0 rates indicate higher than reported infection rates and that depresses the severity/morbidity of the virus. Evidence from some countries (excerpted below) suggest this might be where the numbers are headed long-term. There are obvious outliers such as air pollution in China and Northern Italy, or a massive intentional travel and high population density such as NYC, that could explain much worse outbreaks. There also may be a genetic component. Some ethnicities may be more susceptible than others. There is probably also a weather component and if your local area is going to end up using quarantine policies, it still makes sense to prepare for it. When the herd moves, you get out of the way.

Balding's World:How Fast is Corona Spreading and How Many Undetected Cases Are There?
Iceland has taken a broad population sample that now comprises nearly 5% of the entire population. There is not much detail about the specific testing criteria but the reports are that it was designed to test for corona in the population and not merely sick at the hospital or a medical clinic. According to Icelandic data available from the government, they recently listed 963 confirmed cases for a positive rate of 6.6%. Sounds bad right? Actually, because of the testing criteria, most people did not even know they had corona because they did not feel any worse. Out of the 963 cases only 19 needed hospitalization and only 6 needed ICU care. In other words, while there have been some tragic outcomes, corona is already much more wide spread and it has no or only mild impact on most people who tested positive.

In Holland, a similar thing happened. Hospitals in the Netherlands started seeing reports of corona and had a couple staff members fall ill from corona. To make sure their staff was protected, the conducted a broad population testing on medical staff to see how prevalent corona was among front line personnel. According to their data, after testing 1,353 they found 86 positive tests for corona a rate of (tell me if this sounds familiar) 6.4%. Only half had a fever and most positive cases continued working because they felt either no different or symptoms were so mild. Notably under existing criteria 40% of positive cases would not have been even tested because they did not have a known risk factor.

Westchester county in New York implemented an aggressive testing plan. Their tests were largely by self selected individuals and needed to pass a criteria screening protocol so it is different from Iceland and Holland in key ways. However, they have tested 29,000 people. What have they found? They registered 7,187 positive result for a 25% positive rate. This large jump in positive rate is expected from self selected individuals that pass a screening protocol. So what is the severity? 73 hospitalized and 12 deaths in county. In other words, from positive cases in Westchester county, hospitalization rate of positive cases is running at 1% and deaths are running at 0.26%.
There is another case of broad population testing. The first resident of Vo, Italy died from corona in late February. Local officials being aware of corona virus spreading in China with the help of a local university opted to quarantine and test the entire city of roughly 4,000. Now it is worth noting that Vo is a small remote town in north eastern Italy. It is not one of the major cities which would have lots of international traffic. 89 people out of 3,300 or roughly 3% of the population tested positive after they discovered one death. There is no additional data but they do not report additional tests and actually advised people against going to the hospital unless they had severe problems. Testing two weeks later revealed positive tests dropped to roughly 0.5%.
The Y2K melt-up scenario is still in play.

No comments:

Post a Comment