Coronaviruses such as the newly discovered (SARS-CoV-2), which causes COVID-19, cause respiratory infections of moderate to severe severity, and can even lead to death. The best prevention measures are frequent hand washing with soap and water, avoiding people showing signs of respiratory infections, avoiding touching the face with unsanitised hands and maintaining a healthy lifestyle.
Coronaviruses are a family of viruses that cause respiratory infections in humans. Their name comes from the Latin corona (crown), which refers to the microscopic appearance of the virus. Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and common cold are examples of infections caused by coronaviruses. The new type of coronavirus was first reported in China in December 2019, from where it has spread to all continents except Antarctica.
How the new coronavirus is transmitted
SARS-CoV-2 is transmitted in the same way as other viruses that cause respiratory infections:
- Respiratory, through droplets of secretion produced when the infected person sneezes or coughs
- Through close contact with the infected person (touching, shaking hands)
- By touching contaminated surfaces, after which unsanitized hands are brought to the mouth, nose or eyes.
Once inside the body, the virus reaches the back of the nasal passages and attaches itself to mucosal cells, multiplies and reaches the lungs. From there, it spreads to other tissues in the body.
How long is a person with COVID-19 contagious?
Scientists are still learning new things about SARS-CoV-2. What is currently known is that people with COVID-19 can transmit the virus before they have symptoms (they are asymptomatic). That's why social distancing, wearing a mask, frequent hand washing and home isolation are recommended for those with symptoms suggestive of COVID-19.
How soon after infection do symptoms appear?
The incubation period - the time between infection and onset of symptoms - is up to 14 days. The average duration of symptoms is 5 days.
Who is at higher risk of infection?
Some people are at higher risk of developing complications associated with COVID-19. These include older people and people with various chronic conditions, such as heart disease, diabetes, lung disease, diseases that weaken the immune system, or patients undergoing immunosuppressive treatment. Cancer patients in general are also more susceptible to infections, due to the body being immunocompromised by the tumour and anti-cancer treatments, as these weaken the immune system.
After cure, is reinfection with the new coronavirus possible?
According to the US Centers for Disease Control and Prevention, "the immune response to COVID-19 is not fully understood". Existing opinions are conflicting, however, so far there is not enough scientific evidence to support that infection once acquired will protect against possible subsequent reinfection.
What are the signs and symptoms of COVID-19?
The most common symptoms of COVID-19 are fever, dry cough and fatigue. Other symptoms that are less common and may occur in some people are: pain, nasal congestion, conjunctivitis, headache, sore throat, diarrhoea, loss of taste and smell, rash and redness of fingers and toes (appear as if they are frostbitten). These symptoms are usually mild and come on gradually. In other infected people, only very mild symptoms appear.
Most (80%) affected people recover without needing hospital treatment. About 1 in 5 people with COVID-19 have a severe form with respiratory problems. Older people and those with other health problems (high blood pressure, heart disease, diabetes, cancer) are at risk of complications. However, anyone can get a severe form of COVID-19. Regardless of age, people who have fever and/or cough associated with breathing problems (dyspnoea), chest pain or pressure and impaired movement and speech should seek specialist medical help.