Coronaviruses are RNA viruses which, in most humans, cause mild, in most cases, and severe respiratory infections only rarely.
Supplied with capsules and between 80 and 160 nm in size, coronaviruses are among the main causes of colds, together with rhinoviruses, flu viruses and parainfluenza viruses.
When they infect humans, coronaviruses usually cause symptoms such as runny nose, sore throat, cough, headache and fever.
There are no specific therapies against coronaviruses, but only symptomatic remedies; however, there is not even a vaccine.
In the past two decades, coronaviruses have gained worldwide attention for three reasons: the SARS epidemic, between 2002 and 2003, the MERS epidemic, between 2012 and 2013, and the recent SARS epidemic- CoV-2, which started in late December 2019.
Symptoms and Complications
How do Coronaviruses manifest?
Coronavirus infections induce symptoms of the type showed on the Ministry of Health website:
“[…] the most common symptoms include fever, cough, breathing difficulties.In severe cases, the infection can cause pneumonia, acute respiratory syndrome severe, kidney failure and even death. “
We invite you to read the details on the symptoms on the official website of the Ministry of Health.
In most cases, coronavirus infections present the classic symptoms observed on the most common respiratory tract infections, namely:
- Stuffy nose and runny nose;
- Sore throat;
- Fever between 38 ? C and 39 ? C;
- Inflammation of the nasal mucous membranes, throat and bronchi;
- Loss of appetite;
- Sense of general malaise.
Coronavirus infections concern the upper respiratory tract (from the mouth and nose to the excluded trachea); however, it is not excluded that the viral infectious agent can also reach the lower respiratory tract (from the trachea to the lungs) and cause bronchitis or, worse, viral pneumonia.
The risk of coronavirus pneumonia is higher in older people, in people with heart disease and in people with weak immune systems; this risk also depends on the aggressiveness of the infecting coronavirus: for example, the coronaviruses of MERS, SARS and COVID-19 have proven to cause pneumonia even in people in good health (and this is the reason are feared).
What are Coronaviruses?
Coronaviruses are RNA viruses that, in humans, mostly cause mild respiratory infections limited to the upper airways (nasopharyngeal tract, paranasal sinuses and throat), and only in rare circumstances serious and extensive respiratory infections lower airways (bronchi and lungs).
Together with rhinoviruses, flu viruses and parainfluenza viruses, coronaviruses are among the main cold-triggering agents.
Origin of Coronaviruses
Coronaviruses are viruses that normally circulate among animals.
However, some of them can infect humans too, which naturally makes them the subject of scientific studies.
Infections resulting from viruses capable of spreading from animals to humans are better known as zoonoses.
Why are they called Coronavirus?
Coronaviruses owe their name to the fact that, under the electron microscope, they present themselves as a fringed bulb, very reminiscent of a royal crown or the solar crown.
To make up the fringe surrounding the bulb – which is the viral element within which the RNA genome resides – are the peplomers protein structures necessary for the tropism (i.e. movement) of the infectious agent.
The term “coronavirus” is the result of the union of the Latin word “corona” – which in Italian means “corona” or “halo” – and of the word virus.
Coronaviruses are viruses that are widespread in the human population and, except for special cases (such as the coronavirus SARS or the Novel Coronavirus), do not cause particular concern.
According to an investigation into the viral causes of colds, coronaviruses are responsible for approximately 10-15% of the cases of colds found in the general population.
It is highly probable that many of us, without knowing it, have contracted, even more than once in a lifetime, some coronavirus infection.
How are Coronaviruses made?
Belonging together with toro viruses to the viral family of Coronaviridae, coronaviruses are capsulated viruses (i.e. with envelopes) with helical symmetry, ranging in size from 80 to 160 nm.
The RNA genome (or genetic material) of coronaviruses has a single helix and can be between 26 and 32 kilobases in size.
Among RNA viruses, coronaviruses are the viral agents with the largest genome.
Most Common Coronaviruses
- Alfa coronavirus 229E
- Alfa coronavirus NL63
- Beta coronavirus OC43
- Beta coronavirus HKU1
- SARS coronavirus (SARS Co-V)
- MERS coronavirus (MERS Co-V)
- Novel Coronavirus (SARS Co-V2)
How are Coronaviruses transmitted?
The transmission of coronaviruses in the human population (i.e. between person and person) occurs mainly in two ways:
Through the inhalation of volatile droplets emitted by individuals infected with the virus, when they speak, sneeze, cough or breathe.
This mode of transmission is the most common and the one that causes the greatest number of infections.
Through physical contact with contaminated hands, surfaces, foods or objects.
For example, it can be crucial: touch buttons, telephones, handles or toilets or share crockery, cutlery, etc.
That’s why it’s important to know the rules for preventing coronavirus infection.
For coronaviruses, the incubation period – i.e. the time between exposure to an infectious agent and the appearance of the first symptoms – can vary from 1 to 14 days; on average, however, it stands at 5-7 days.
During the incubation period, several coronaviruses, including the SARS coronavirus and SARS-CoV-2 are contagious; in practical terms, this means that an infected person can transmit the infection to others, when the symptoms of it have not yet appeared (and the individual who is incubating it is apparently healthy).
In general, coronavirus infections are more likely during the fall or winter season; however, it is good to remember that coronaviruses can infect humans all year long.
Another risk factor that strongly affects the possibility of developing a coronavirus infection is the close proximity to a contaminated individual.
To know the exact type of coronavirus that has infected an individual, it takes a few laboratory tests on the blood and nasopharyngeal swabs.
However, it should be noted that these tests are carried out only if there are particular reasons; normally, in fact, doctors rely only on physical examination, followed by anamnesis (or clinical history).
How are Coronaviruses treated?
There is no specific treatment against coronaviruses and the infections they cause.
Typically, to a healthy patient with a common coronavirus infection, doctors recommend:
- Stay at complete rest until the symptoms disappear.
- Drink lots of fluids (rehydration), to avoid dehydration.
- Take an anti-inflammatory and analgesic drug against sore throat and fever. One of the most used drugs is paracetamol, followed by ibuprofen and aspirin (N.B: remember that aspirin is absolutely contraindicated for subjects under the age of 16, due to the danger of Reye’s syndrome)
Considering the consequences deriving from the global spread of SARS-CoV-2 (the coronavirus responsible for COVID-19), many countries of the world, including Italy, are looking for a drug that is able to fight the infection.
Remdevisir (an antiviral initially thought to manage Ebola) and RoActemra (also known as Tocilizumab, is a medicine used against rheumatoid arthritis exclusively in hospital and intravenously).
Is there a vaccine against Coronaviruses?
There is no vaccine against coronaviruses.
However, there are behaviours – also recommended by the WHO and the ISS – which effectively reduce the risk of infection.
These behaviours include:
- Careful (40-60 seconds) frequent washing of hands with soap and hot water or with alcohol-based solutions, specifically designed to not irritate the skin. Washing your hands, in fact, eliminates the virus;
- If you are unable to wash your hands, do not touch your eyes, nose and mouth;
- Avoid contact with people with a coronavirus infection or with suspicious symptoms as much as possible;
- In case of sneezing or coughing, cover with the inner crease of the elbow or with a tissue, mouth and nose;
- Clean the surfaces most in contact with the hands with a certain frequency using a solution based on chlorine or alcohol (there are special disinfectants).
How to Avoid Infecting Other People?
Stay at home until the end of the infection, avoid contact with other people, cover your mouth and nose with a tissue at each sneeze or cough (and of course throw the tissue immediately after), take care to disinfect objects and the most touched and accessible surfaces are the main precautions that a person with a coronavirus infection must follow, to avoid contaminating someone else.
Coronavirus: map and numbers of contagions in real time
To know the updated data about the spread of Coronavirus in Italy and in the world, you can consult the official WHO website and the official website of the Ministry of Health.
WHO has made available interactive maps that allow you to select the different geographical areas to know the data of each of them.
On the website of the Ministry of Health, however, the data referring to the number of positive, deaths and healed are reported and the detail of the infections by region is also reported.
- Coronavirus Situation in Italy
- Coronavirus map of the Situation in Europe
- Coronavirus map of the Situation in the World