Do you know what SARS-CoV-2 is? What about COVID-19?
It’s technically incorrect to refer to our current health crisis as ‘The Coronavirus’ when it’s only one strain of several in the coronavirus family. It’s also incorrect to identify the current coronavirus as COVID-19 when the latter is a disease caused by the 7th strain. After a brief history, I’ll explain the differences and correct terminology.
WHAT ARE CORONAVIRUSES
Coronavirus are a family of viruses thought to be zoonotic i.e. spread from non-human animals to human animals. They can also inflict disease on birds. In chickens and humans, the upper respiratory track becomes diseased. The most lethal diseases to humans are COVID-19, SARS AND MERS. There are no vaccines for these.
Coronaviruses were first discovered in farm chickens in the 1930s but only in humans in the 60s.
There are 7 strains of human coronavirus. 4 are considered minor, causing 15% of common colds. However, they can also cause pneumonia and bronchitis which can be lethal to patients weakened by other afflictions e.g. asthma, tuberculosis, high blood pressure.
The 3 severe strains, all worryingly new to this century, are:
- SARS-CoV (Severe acute respiratory syndrome)
- SARS-CoV-2 (Severe acute respiratory syndrome 2)
- MERS-CoV (Middle East respiratory syndrome)
‘CoV’ means ‘Corona Virus’. The name is derived from the crown of bulbous formations atop the body of the virus.
SARS-CoV-2 and CORONAVIRUS HISTORY
SARS-CoV was discovered in China in 2002, with the outbreak limited but lasting until 2004. The disease it causes is SARS.
SARS-CoV-2 is genetically similar to SARS-CoV and a bat coronavirus. It was also discovered in China, but the disease it causes is COVID-19. It’s the current crisis we face. It has a lessor mortality rate than its predecessor but is killing more because it’s more infectious.
MERS-CoV if the most frightening with a case fatality rate of 37%. Although it appears to have originated in Saudi Arabia, there were cases in Tunisia, and a large outbreak in South Korea in 2015. The South Korean government understood the danger of coronaviruses which is why they’ve responded so well to SARS-CoV-2.
The most common symptoms to these 3 are fever, dry cough and shortness of breath.
The virus is spread via coughing, sneezing and talking but secondary contamination can occur through touching surfaces covered by those infected droplets. Depending on the type of surface, the virus can last up to 3 hours in the air and as many as 3 days on metal and plastic (you’ll never look at your cellphone the same way again).
Humans have infected cats in Belgium and Hong Kong, and, more famously, the tigers at the Bronx Zoo in New York. Dogs appear to be less susceptible. I’ve been unable to find out how long SARS-CoV-2 can survive on fur but, so far, there’s no evidence to support pets passing it back to humans. Nevertheless, it’s plausible so I suggest we be careful until the science is in.
‘COVID-19’ stands for ‘COronaVIrus Disease 2019’.
The onset of symptoms is 5 days on average, but may range from 2-14 days. One reported case took 27 days but I don’t know if that was confirmed.
Recovery takes 2-6 weeks. Those who’ve died have lasted up to 8 weeks.