by Fernando Caracena ©Fernando Caracena 2020
The COVID-19 virus, known as the Corona Virus, started in the city of Wuhan China sometime before Christmas and by the time of the Chinese New Year, Wuhan the city of eleven million people was in total lockdown. Since then, the virus has spread worldwide chiefly by air travel, but in some cases by ships. For those interested in following the spread of the virus using information from a credible source see the Coronavirus COVID-19 Global Cases by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. The more mathematically minded readers might want to model the spread of the virus for themselves. The spread of the virus has exponential growth characteristics. See a past post on "Modeling Technological Growth". To see an in depth discussion the go to the web page, The mathematics of diseases by Matthew Keeling. An article about analyzing the spread of the virus in China appeared in the journal Science, Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2). Dr. Francis Boyle Creator Of BioWeapons Act Says Coronavirus Is Biological Warfare Weapon is the title of an article in the journal geopolitics and International Relations, GreatGameIndia.
At the moment, some scientists believe that the Wuhan virus is especially deadly to the Han people and to the older people around the world, particularly those who have underlying health issues. Note however that Note however that a 103-year-old Iran woman has survived the Coronavirus. Earlier reports stated that a man over 100 years old also similarly survived. This disease is spread very easily among humans. It is airborne and the virus can rest for hours on some surfaces. It totally obliterates modern life if it is also as deadly as some claim. Everywhere that people gather and touch things is prime transmission territory for the virus. From studying videos leaked out of Wuhan, it is my opinion that Chinese officials applied the Hoof and Mouth disease model to the growing epidemic. The following is a quote from Keeling's article:
Foot and mouth disease can again be described by a simple SIR model. However, because its spread within a farm is so rapid, most models classify the entire farm as either susceptible, infectious or recovered. These farm-level models have an R0 of around 50. Control of the disease is a difficult problem - very stringent measures need to be taken to overcome this large value of R0.
Foot and mouth disease can again be described by a simple SIR model. However, because its spread within a farm is so rapid, most models classify the entire farm as either susceptible, infectious or recovered. These farm-level models have an R0 of around 50. Control of the disease is a difficult problem - very stringent measures need to be taken to overcome this large value of R0. Vaccination is not a useful policy as it only offers partial protection and must be repeated every 4-6 months. Instead, by destroying all infected animals and limiting the movement of livestock it is hoped that the transmission between farms can be reduced sufficiently that the disease will die out.
We saw in videos from Wuhan that the response to COVID-19 was draconian. In that case, one million people were locked down and contained within the city. I will not dwell on the details, but watching Japanese news, I heard the commentator saying that Japan had to find the way to control the virus the Japanese way rather than the Chinese way. Now we have to find a way to control the virus in the USA the American way and not the Chinese way.
Many of the characteristics of the virus are being actively debated by experts in the field. This includes the value of R0, initially estimated to be 2.2 to 2.7, but which some now think to be between 4.7 and 6.6. The city council of Seattle, WA, one of the hardest Coronavirus-hit cities in the US, put out a report, "What we know now about the coronavirus, and the response", in which they discuss these issues. A study, reported in PUBMED [Int J Infect Dis. 2020 Feb 22;93:201-204. doi: 10.1016/j.ijid.2020.02.033.] that is based on the spread of the virus in the quarantined Diamond Princes cruise ship ["Estimation of the reproductive number of novel coronavirus (COVID-19) and the probable outbreak size on the Diamond Princess cruise ship: A data-driven analysis"] came to the following conclusions:
The median with 95% CI of R0 of COVID-19 was about 2.28 (2.06-2.52) during the early stage experienced on the Diamond Princess cruise ship. The future daily incidence and probable outbreak size is largely dependent on the change of R0. Unless strict infection management and control are taken, our findings indicate the potential of COVID-19 to cause greater outbreak on the ship.