Coronaviruses are a large family of viruses that cause illnesses ranging from the common cold (some seasonal viruses are coronaviruses) to more serious diseases such as MERS or SARS. The virus that has been identified in China is a new coronavirus called SARS-CoV-2. The disease caused by this virus has been named COVID-19.

What are the symptoms of COVID-19?

The main symptoms are:

• Sore throat
• Dry cough
• High temperature
• Shivering
• Feeling faint
• Muscle aches
• Breathing difficulties

One of these symptoms is sufficient to prompt a diagnosis.

The elderly and those with existing health conditions (diabetes, immune deficiency, chronic respiratory disease, cancer, etc.) are more likely to develop a severe form of the disease.

As with many infectious diseases, people with chronic underlying conditions (people with respiratory disease, those who are frail or elderly, etc.) have a higher risk of developing a more severe form of the disease.

Close contact (within less than 1 metre) with an infected person is required for the virus to be transmitted, and the longer the contact, the greater the risk.

Transmission occurs via respiratory droplets containing the virus which are expelled when people cough or blow their noses.

There are two ways of becoming infected:

• If droplets directly reach the mouths or noses of people nearby (within a radius of 1 metre)
• It is also possible to become infected by touching a surface or object which has been contaminated with respiratory droplets (door handles, when shaking someone’s hand, etc.) and then touching your mouth, nose or eyes with your hand

According to current understanding, the incubation period for COVID-19 is between 2 and 14 days, which means that if someone who has been exposed does not develop any symptoms within 14 days, they have not contracted the disease.

The disease is diagnosed by identifying the virus using a complex, non-automated technique, RT-PCR. In France, only university hospitals have this capability.

No specific treatment for this new coronavirus has so far been identified. Several treatments currently used against other viral diseases are now being evaluated to see if they could be used to treat COVID-19. In the meantime, treatment focuses on symptoms.

Available information suggests that the virus can cause symptoms similar to those caused by a mild case of flu, as well as more severe symptoms.

The disease can also progress over time in the same patient.

Patients with chronic pre-existing conditions such as high blood pressure, cardiovascular disease, diabetes, liver disease and respiratory disease, as well as the elderly, appear to be more likely to develop severe forms of COVID-19.

If you have no symptoms of the disease following two weeks of self-isolation, this could mean two things:

• You are not infected
• You have the virus, but you will not develop symptoms of the disease (these generally appear five days after contamination but can take up to fourteen days in some cases).

Either way, this does not mean that you can confidently end your period of self-isolation with no risk.

• If you have not yet been infected, then you still run the risk of contracting the virus if the epidemic is ongoing.
• If you are an asymptomatic carrier, then that’s great for you but please note that you are still potentially contagious to others.

This is why the general lockdown of the population may be extended beyond the two weeks required to know if you are sick.

In light of available data on the ability of coronaviruses to survive outside (3 hours on dry, inert surfaces) and given transport times and conditions, the risk of becoming infected by the new coronavirus by touching an imported item is considered to be nil.

Apply standard hygiene measures (washing hands, cleaning surfaces) after opening a package.

Modelling work is underway. The health authorities are carefully monitoring developments in the situation around the world.

Under the right conditions, traces of the virus can survive for between several hours and several days on a surface contaminated with droplets.

However, some experts say that the viral load of the virus diminishes very quickly in an external environment. Within a few minutes, the surface is no longer contaminated.

As a precaution, it may be useful to clean surfaces frequently and after they have been touched, particularly if they are visibly dirty.

If you have touched a potentially contaminated surface (lift button, door handle, supermarket trolley, etc.), the most important thing is to comply with barrier measures:

• Avoid touching your eyes, nose and mouth
• Wash your hands thoroughly

To date, there are no sufficiently robust scientific arguments to support this. Research is currently under way to better understand the virus.

It is worth remembering that the vast majority of virus mutations are neutral, and the remainder are more often than not beneficial to humans. In the majority of epidemics, viruses evolve to become less dangerous but more easily spread.

After encountering a virus, our bodies develop immune defences known as antibodies which enable them to protect themselves against the virus. Although we are still at an early stage in terms of being able to answer this question, scientists consider initial data to be reassuring since there do not seem to have been any genuinely confirmed cases so far where re-infection has occurred.

There is always a risk, and the longer and closer the contact (more than 15 minutes, less than 1 metre), the higher the risk of infection. This is why social distancing and barrier measures should be applied. It is possible to live with a case of COVID-19 in your home if you comply scrupulously with barrier measures.

No, there is no evidence that the virus can be transmitted by mosquitoes or any other animal for that matter. The COVID-19 coronavirus is transmitted between humans, via respiratory droplets.