The coronavirus is spreading – Is it possible to become a pandemic?
A new virus is spreading, with confirmed cases on four continents and thousands infected. Currently, there is no cure, and as the virus can mutate further now, the fear of a global disease outbreak is growing. But is it a realistic fear, and what is needed for the virus to become a real killer virus?
Infectiousness can create a pandemic
One of the most important parameters of a virus spread is its ability to infect. This applies to both the transmission capacity of animals to humans and those between humans.
1. Isolated case - virus infects only from animals to humans
The microorganism only infects from animals to humans. It is transmitted from animals, and humans get sick, but it cannot continue, and man is a "dead end". Such is the case with, for example, West Nile Fever, rabies, and Borrelia.
2. Limited outbreaks - viruses are limited to humans
The microorganism transmits from animal to human and limited between humans. The microorganism is transmitted from animals, and humans become ill. Few of the ill infect other people, but not effectively, which is why the chain of infection is broken. The disease is close to developing into human disease and lacks only the last. This applies to bird flu and nipah virus.
3. Epidemic - Viruses are effectively transmitted between humans
The microorganism transmits from animal to human and then between humans. The microorganism is transmitted from animals, and humans become ill. It manages and can infect new people, resulting in a completely new disease. This is the case, for example, of swine flu (H1N1), plague, SARS, ebola, yellow fever, and dengue fever.
The epidemic becomes a pandemic if it spreads on a global scale.
Mutation type 1 (antigenic operation):
Small mutations occur in the virus
A viral gene is less altered.
The mutations create a new variant
Therefore, over time, it accumulates more and more mutations and may, at some point, develop into a new variant of the original virus.
Mutation type 2 (antigenic switch):
Viruses attack cells
Two or more viruses attack a cell.
The virus's copy is copied
Inside the cell's core, the virus's copy is copied
A new virus occurs
This creates a new virus with properties from the original viruses.
In December 2019 came the first reports of a mysterious virus that flourished in the Chinese millionth city of Wuhan, giving symptoms such as cough, high fever, difficulty breathing, and pneumonia.
Since then, the disease has appeared in North America, Europe, and Australia, and the latest figures show that 6,000 people have been infected and that hundreds of people have died.
So there is no doubt that the virus is spreading, but how serious is it really? And is there a risk of a global pandemic?
From peaceful to a dangerous virus
The new virus, named 2019-nCoV, was identified in early 2020 as a so-called coronavirus.
Coronavirus is an extremely common type of virus that is behind most of the winter’s colds and respiratory tract infections.
But in rare cases, a coronavirus can develop into a particular infectious disease, a so-called zoonosis, which means that the virus begins to spread from animal to human.
The first people infected by the new coronavirus worked on or often visited Wuhan’s meat and fish market, a place where people and animals have close and regular contact.
The market has the right conditions for infection to be spread between animals and humans, and there is also broad agreement that 2019-nCoV has arisen here. Chinese scientists currently suspect that snakes are behind the first infection, but that has not yet been confirmed.
Ebola and SARS also infected animals
Many of the most deadly diseases of modern times stem from animals, such as Ebola, HIV, and SARS and MERS. The latter two are, just like the 2019 nCoV, coronavirus.
So far, only elderly people and people with impaired health have lost their lives due to the new coronavirus. And even though the virus seems to be infected between people, you must have been in close contact with the infected to get the disease yourself.
The World Health Organization WHO has not assessed the situation as an ‘international health crisis’ but only a crisis that is limited to China, where most of the infected are also found.
Also, the European Center for Disease Prevention and Control (ECDC) considers the risk of a greater spread of infection in Europe.
The risk of a fatal pandemic is currently low since the coronavirus infectivity is moderate, and mortality is low. But the risk picture can change quickly.
New studies show, for example, that the spread of infection can take up to 14 days before the symptoms appear, making it difficult to detect the infection and isolate the virus. The long incubation period becomes especially dangerous if the new virus mutates further.
Mutations can create a killer virus
The new coronavirus has already mutated as it moved from animal to human and then began to infect humans. It is likely to continue to mutate, which could pose a danger.
Coronaviruses belong to the group of RNA viruses, which are somewhat more unstable than DNA viruses.
This is because the enzyme that helps the RNA virus to reproduce is harmful at correcting errors that can occur in the process – and it causes a very high degree of mutations.
Mutations in an RNA virus can occur in so-called antigenic operation or antigenic alteration.
Antigenic activity is characterized by small natural mutations in the virus, which over time, develop into a new variation and confuse the immune system. For example, an antigenic operation is a reason why many people can get the flu several times during the same season.
Antigenic paralysis is another type of mutation where two or more viruses are combined and form a new type of virus.
The genetic change is the reason for new diseases that our immune system does not recognize and can protect us from.
The pandemic with the swine flu H1N1 in 2009, for example, arose as a result of a genetic change with viruses from pigs, humans, and birds. The swine flu had many similarities to the Spanish disease, and an estimated up to 203,000 people died of the disease.
However, mutations due to a genetic change do not occur as frequently as mutations of a genetic shift.
If the coronavirus mutates, it can change two critical parameters, regardless of the type of mutation: its infectivity and its mortality. Mutations can at best weaken the virus’s properties – but it can also strengthen them and make them more dangerous.
However, it is impossible to predict, and therefore it is crucial to monitor and learn more about the new virus so that you can get it under control
The researchers tame SARS
SARS was a new form of coronavirus that emerged in 2002. The virus hit the respiratory tract, among other things, and had a high mortality rate of ten percent, prompting the World Health Organization to sound an alarm quickly.
In the fight against SARS, the surveillance of the disease in both humans and animals was put into systems.
Also, WHO coordinated modern technology, communication, and laboratories in an international network of experts. Besides, at airports, heat scanning is often used to reveal the disease.
Day by day, they shared data and laboratory tests that quickly made it possible to identify the source of SARS and then constantly monitor developments closely.
The last major SARS outbreak came in 2003.
The infection spreads from animal to human
Three factors determine whether an infectious disease that occurs in an animal can be transmitted to humans and developed into a disease that infects humans. The microbe will come into contact with a pet host, from where it will find humans, to eventually overcome the species barrier and our immune system.
1. Pet host
The decisive factor is whether the microorganism is present in one or many animal species, the density of the hosts, and whether the disease is transmitted directly at, for example, bites or if it is transmitted indirectly.
2. Human contact
How and how often we encounter the microorganism determines if it is transmitted. It can happen by penetrating into its habitat, increasing the density of disease-carrying blood-sucking insects, or changing behavior and eating more meat, for example.
3. Probability of infection
If the organism can overcome closely related mammalian immune systems, we should be on our guard, while we do not have much to fear from diseases of distantly related animals. The duration and frequency of contact are essential, as well as good hygiene is crucial for whether animal microorganisms can make contact.