General notions and epidemiology:

COVID-19 is an infectious respiratory disease caused by the virus called SARS-CoV-2 belonging to the coronavirus family.

It is believed that the responsible virus is of zoonotic origin (i.e. transmitted, directly or indirectly, from the animal to man), but in February 2020 the predominant mode of transmission results from man to man, generally through infected water and mucus particles (droplets of Flügge) which people release by sneezing or coughing and which are then inspired by another individual.

Around mid-December 2019, health authorities in the city of Wuhan in China (about 11 million inhabitants) found the first cases of patients showing symptoms of “pneumonia of unknown cause”.

Following some investigations it was discovered that this first group of patients was somehow connected to the local wholesale market where fish, chickens, pheasants, bats, marmots, snakes, spotted deer and rabbit organs were sold in addition to others wild animals.

It was immediately assumed that it was a new coronavirus from an animal source (a zoonosis).

The strain responsible for the outbreak was identified in early January 2020 and designated as SARS-CoV-2 (also known as Wuhan’s New Coronavirus), while its genome was released on January 10.

In February 2020, the mortality and morbidity rates due to the disease are not yet clear, although WHO suggested that this value could be around 2%.

Epidemiologically, SARS-CoV-2 is a respiratory virus that mainly spreads through close contact with a sick person.

Contagion can therefore occur through coughing, sneezing, direct personal contact.

Another way of contagion is the hands, that is, touching the mouth, nose or eyes with contaminated (not yet washed) hands.

In rare cases, infection can occur through faecal contamination.

Normally respiratory diseases are not transmitted with food, which in any case must be handled respecting good hygiene practices and avoiding contact between raw and cooked food.

Symptoms:

Patients experience flu-like symptoms: fever, fatigue, dry cough and sometimes shortness of breath accompanied by difficulty breathing and a runny nose.

In more severe cases, often found in subjects already burdened by previous pathologies, pneumonia develops, acute renal failure, up to even death.

In most cases, vital signs appear generally stable at hospitalization, while blood tests commonly show a low white blood cell count (leukopenia and lymphopenia).

Generally the symptoms are mild and slow in the beginning.

Diagnosis:

On January 15, 2020, the World Health Organization – WHO published a protocol concerning the diagnostic test for SARS-CoV-2, developed by a team of virologists from the Charité University Hospital in Berlin (Germany).

Subsequently, WHO published several additional diagnostic protocols.

Current diagnostic practice involves a first test performed on a pharyngeal swab.

The test uses real-time reverse polymerase chain reaction (rRT-PCR).

The reverse polymerase chain reaction technique is a variant of the polymerase chain reaction (PCR) technique.

This technique consists in the synthesis of a double-stranded DNA molecule from an RNA mold.

Once a sample of genetic material has been taken, the swab is immersed in a gel and sent to the analysis laboratories, which have the task of checking whether the virus is positive or not.

Once arrived at the laboratory, the technicians analyze the sample, to determine the possible presence of bacteria and portions of the generic code of the coronavirus.

The test result can take, in standard conditions, from 4 to 6 hours.

If the pharyngeal swab is positive for COVID-19, a further check is made, as required by the protocol, to definitively confirm the infection.

Prognosis:

The incubation period of the virus is approximately 14 days.

As we have already said, the mortality rate is currently around 2%.

The virus affects people of all ages, both male and female.

Many people either recover spontaneously or thanks to supportive therapies.

Treatment:

There is currently no official treatment for COVID-19 disease.

Supportive therapy can be very effective, as well as some antivirals similar to those used for the Ebola virus (Remdesivir) and HIV (Lopinavir and Ritonavir in combination, Darunavir) have proven effective in association with oxygen therapy.

Chloroquine, used for malaria, is also under study.

Various research centers around the world are working hard to find an effective vaccine for the virus.

Prevention:

For preventive purposes, the World Health Organization recommends:

– wash your hands often with soap and water or with alcohol-based solutions to eliminate any contamination with the virus.

– keep a certain distance (at least one meter) from other people, especially when they cough or sneeze or if they have a fever, because the virus is contained in the droplets of saliva and can be transmitted by breathing at close range.

– avoid touching your eyes, nose and mouth with your hands not yet washed or when you are in areas where people are present (e.g. plane, train, meeting rooms, etc.).

– Do not drink from the same bottle or glass of others.

– Cover your mouth and nose with a tissue (preferably disposable) or with your arm (with your elbow bent), but not with your hand, if you cough or sneeze.

– Ventilate all rooms as often as possible.

– Avoid staying as much as possible in areas where there are crowds of people in closed places (for example airplanes, trains, subways, couriers, entertainment venues, etc.).

– Use protective masks of type Ffp2 and Ffp3, which have a filtering efficiency of 92% and 98%.

The masks have a dual function: they protect against the risk of contagion and should be worn if you have a cough or a cold to protect others.

The masks, however, do not ensure total protection as you have to be careful of the eyes (another way of contagion) and hands, which must be washed frequently and carefully.