PANDEMIC | 2. What Affects the Spread of the Coronavirus?

This is the second of a series of posts on the subject of the coronavirus death rates by country. See also posts on March 19 (#1, Why is Germany's death rate so low?) Virus Deaths Tracker (FT).

March 20, 2020–The New York Times has an informative article today showing the growth of COVID-19 cases in each country. A sample of the charts is at right, for the United States. It is illuminating to see the same exponential pattern occurring in virtually every country that has a significant number of cases. (It would be easier to compare countries' data if all of the countries were on the same chart, preferably logarithmic, so that the rate of change is easier to gauge.)

The charts show a series of daily snapshots of the progress of the novel coronavirus in each country. The chart shows the number of confirmed cases of infection by the virus. What are the factors that determine the spread among countries like Italy on the high-mortality end and Germany on the low end? Here are some early theories:

1. How quickly a country created social distance. Hand-shaking (until this pandemic) has become a world-wide custom. But some countries are used to even closer social greetings, such as hugging and kissing. Amsterdam is proud of its three-kiss greeting (that is the meaning of the three Xes in its shield). Self-isolation may be harder to enforce in some countries. The closeness of families in Italy is viewed as a problem in getting more vulnerable age groups in the population to keep their distance from socializing younger generations.
2. A city's density, as an indicator of how much of a magnet it is. If, as most people believe, the virus started in Hubei, China, then the virus somehow made its way from there to each country, probably carried by human beings. Travelers on busses, trains and airlines are likely carriers, and one can be a carrier with no symptoms. Hubei is center of transportation and manufacturing system in China, which made it an easy place to spread to virus. New York became an epicenter because of its central role in communications, finance, fashion and technology.
3. How much testing is done, when it is done, and when it is reported. New York State has authorized a range of manual, semi-automated and automated testing approaches and the numbers of confirmed cases of the SARS-CoV2 has been rising rapidly. The State says it is now testing 10,000 people a day, has tested 32,000 people in total, many more than any other state, and has found 7,100 cases of positive readings, nearly 40 percent of the total for the nation (19,624). 

The Times story references the need to "flatten the curve," i.e., the need to take quick action to test people with symptoms of the virus and quarantine them and provide hospitalization for the very sick, who will suffer from exacerbation of respiratory, heart or other immunity problems they have.

Additional Data to Get. The charts show the "curves" themselves in each country, indicating confirmed infections, so that we can better understand the number of people who are hospitalized or quarantined, and the coming demand for medical facilities. Now we need to put these numbers together with other data:

• Hospitalization and death ("case-fatality") rates. It would be useful to know how many are hospitalized in each phase, since the greatest concern is about a likely shortage of intensive-care-unit (ICU) hospital beds, ventilators and respirators. New York State reportedly (as of the Governor's press conference on March 21) has only 3,000 ICUs, 80 percent of which are occupied. It will need at a minimum twelve times that number based on the experience in Italy and other countries. A survey of more than 200 U.S. cities by the U.S. Conference of Mayors shows great concern about running out of supplies of masks and ventilators. The cities need collectively 28 million surgical (N95) masks, 8 million test kits and 139,000 ventilators. Reminds me of a play by Shaw that I first saw at the Abbey Theater in Dublin, The Doctor's Dilemma; read it here free–https://www.gutenberg.org/files/5070/5070-h/5070-h.htm.
• Names of those who have developed immunity. This could be the base for treatments that could save lives and slow spread. Dr. David Posnett says: "If we only knew who had developed immunity to the virus.  Immunity may occur in someone who had the virus (either with symptoms or without), got better and developed IgM and IgG antibodies.  We know that happens.  If you are declared immune, you can safely go back to work which might help the economy.  You are safe as a healthcare worker.  You are safe to go buy groceries. You are safe to be around your loved ones.  You could donate plasma at the local Blood center and plasma with lots of antibodies could be administered to patients dying in the ICU (passive immunotherapy used previously against the Spanish flu and against Ebola for example)."