In the first of the series, I looked at how the SARS-CoV-1 virus that caused the short-lived SARS (severe acute respiratory syndrome) epidemic of 2002/2003 looks, from an Intelligent [sic] Design perspective (if you believe that superstitious nonsense), to have been a prototype which Creationism's divine malevolence built on to produce the much more devastating SARS-CoV-2 virus. This virus causes COVID-19 (Corona VIrus Disease 2019) and is still posing a serious threat to life, long-term health, health services and economies world-wide, almost 3 years after it was first detected, at the end of 2019.
SARS-CoV-2 is a member of the coronavirus family, so-called because they have prominent 'spike' proteins on their surface which give the virus particles a crown-like (corona) appearance under sufficient magnification. They are all RNA viruses that have a single strand of RNA as their functional genome. The spike proteins are used by the virus to lock onto the surface of cells, prise them open and inject their RNA into the cell, where it uses the cell's own metabolic processes to make more virus particles and kill the cell.
In this article reprinted from The Conversation under a Creative Commons license, reformatted for stylistic consistency, Lindsay Broadbent, a Research Fellow at the School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, explains the history of coronaviruses. The article is undated but reads as though it was written during the first lockdown in about April or May 2020.
The original article can be read here.
Coronaviruses – a brief history
Credit: Master1305/Shutterstock
Most of us will be infected with a coronavirus at least once in our life. This might be a worrying fact for many people, especially those who have only heard of one coronavirus, SARS-CoV-2, the cause of the disease known as COVID-19.
There is much more to coronaviruses than SARS-CoV-2. Coronaviruses are actually a family of hundreds of viruses. Most of these infect animals such as bats, chickens, camels and cats. Occasionally, viruses that infect one species can mutate in such a way that allows them to start infecting another species. This is called “cross-species transmission” or “spillover”.
The first coronavirus was discovered in chickens in the 1930s. It was a few decades until the first human coronaviruses were identified in the 1960s. To date, seven coronaviruses have the ability to cause disease in humans. Four are endemic (regularly found among particular people or in a certain area) and usually cause mild disease, but three can cause much more serious and even fatal disease.
The first coronavirus discovered was in chickens.
Source: Pieter/Shutterstock
Common cold
Coronaviruses can be found all over the world and are responsible for about 10-15% of common colds, mostly during the winter. The coronaviruses that cause mild to moderate disease in humans are called: 229E, OC43, NL63 and HKU1.
The first coronaviruses discovered that are able to infect humans are 229E and OC43. Both of these viruses usually result in the common cold and rarely cause severe disease on their own. They are often detected at the same time as other respiratory infections. When several viruses, or viruses and bacteria, are found in patients this is called co-infection and can result in more severe disease.
In 2004, NL63 was detected for the first time in a baby suffering from bronchiolitis (a lower respiratory tract infection) in the Netherlands. This virus has probably been around for hundreds of years, we just hadn’t found it until then. A year later, in Hong Kong, another coronavirus was found – this time in an elderly patient with pneumonia. It was later named HKU1 and has been found to be present in populations around the world.
Deadlier strains
But not all coronaviruses cause mild disease. Sars (severe acute respiratory syndrome) caused by SARS-CoV was first detected in November 2002. The cause of this outbreak wasn’t confirmed until 2003 when the genome of the virus was identified by Canada’s National Microbiology Laboratory. Sars bears many similarities to the current pandemic of COVID-19. Older people were much more likely to suffer severe disease and symptoms included fever, cough, muscle pain and sore throat. But there was a much greater chance of dying if you had Sars. From 2002 until the last reported case in 2014, 774 people died.
A decade later, in 2012, there was another outbreak involving a newly identified coronavirus: MERS-CoV. The first case of Middle East respiratory syndrome (Mers) occurred in Saudi Arabia. There were two further Mers outbreaks: South Korea in 2015 and Saudi Arabia in 2018. There are a handful of Mers cases every year, but the outbreaks are usually well contained.
So why did Sars or Mers not result in pandemics? The R0 of both Sars and SARS-CoV-2 is about two or three (although some more recent estimates of the R0 for SARS-CoV-2 are around five), meaning that every infected person is likely to infect two or three other people. The symptoms of Sars were more severe, so it was much easier to identify and isolate patients.
The R0 of Mers is below one. It is not very contagious. Most of the cases have been linked to close contact with infected camels or very close contact with an already infected person.
One of the main challenges in containing the SARS-CoV-2 outbreak is that symptoms can be very mild – some people may not even show any symptoms at all – but can still infect other people. SARS-CoV-2 is not as deadly as either Sars or Mers, but because it can spread undetected, the numbers of people it will infect and the numbers that will die will be higher than any coronavirus we have ever encountered. So please, stay at home.
Lindsay Broadbent,Research Fellow, School of Medicine, Dentistry and Biomedical Sciences,
Queen's University Belfast
Copyright: © 2022 The Conversation Trust (UK) Limited. Open accessReprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
You have to admire such determination even if you find its obsessive mendacity repugnant and worthy only of utmost contempt.
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