Dear Janus, Earth Angel and Poet:

I want to correct a couple of things, having read Wikipedia’s entry on SARS-CoV-2:

1. it is an RNA virus, not a DNA virus.

2. It does not stay on surfaces for around thirty days, but around three das (“Preliminary research indicates that the virus may remain viable on plastic and steel for up to three days, but does not survive on cardboard for more than one day or on copper for more than four hours”, Wikipedia.

Everything else that you explained in your recent two posts seems to be true and it is very useful to me. To add, having looked at Wiki’s entry: “SARS-CoV-2 belongs to the broad family of viruses known as coronaviruses. It is a positive-sense single stranded RNA virus. Other coronaviruses are capable of causing illnesses ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS). It is the seventh known coronavirus to  infect people, after 229E, NL63, OC43, HKU1, MERS-CoV, and the original SARS-CoV…. Its RNA sequence is approximately 30,000 bases in length

– what is important to remember regarding RNA viruses vs DNA viruses is that “RNA viruses generally have very high mutation rates compared to DNA viruses” (Wiki, on RNA viruses).

Back to the wiki entry I started with, it reads: “Based upon the low variability exhibited among known SARS-Cov-2 genomic sequences, the strain is thought to have been detected by health authorities within weeks of its emergence among human population in late 2019”, the earliest case of infection thought to have been on Nov 17, 2019 in China, spread to more than 100 countries, then, on Jan 11, 2020 WHO designated it as a “Public Health Emergency of International Concern”, and on March 11, 2020, WHO declared it a pandemic.

“The basic reproduction number of the virus has been estimated to be between 1.4 and 3.9. This means that each infection from the virus is expected to result in 1.4 to 3.9 new infections when no members of the community are immune and no preventative measures are taken”.

Regarding “basic reproduction number”, wikipedia: “In epidemiology, the basic reproduction number of an infection can be thought of as the expected number of cases directly generated by one case in a population where all individuals are susceptible to infection..(where there is) absence of ‘any deliberate intervention in disease transmission”.

anita