From person to person
You can become ill if you are infected with SARS-CoV2, the novel coronavirus that causes COVID-19. Your body defends itself against the virus in different ways. The first line of defence is your skin. It forms a kind of wall around your body that is impenetrable to many pathogens. In addition, there are numerous other lines of defence that a pathogen must pass through before you can become ill, such as your immune system. For that reason, a single virus particle is rarely enough to make you sick. You will (usually) have to come into contact with many virus particles before you become ill.
A person who is ill from the novel coronavirus produces millions of copies of the virus inside their body. The virus is mainly found in the lungs, but also in other ‘moist’ parts of your body, such as your throat or nasal cavity. When you sneeze or cough, you are not just pushing out air: lots of droplets also come out of your lungs, throat or nasal cavity. The novel coronavirus spreads through these droplets.
Coughing or sneezing
If other people inhale those droplets, or get them in their mouth, nose or eyes, for example via their hands, they may become infected with the virus. The sicker you are, the more you will cough and/or sneeze – and that means that you will be spreading the virus more.
Large or small droplets
Although the novel coronavirus is still a fairly new virus, and there is much we still do not know about it, we do know that other people are mainly infected via the somewhat larger droplets. The larger droplets do not travel as far (rarely making it beyond 1.5 metres). Under normal circumstances, it would appear that there is a minimal risk of spreading the novel coronavirus through the small droplets that remain suspended in the air (known as aerosols). This is also supported by various scientific articles on this subject. This information also shows that ventilation systems (like air conditioners) do not seem to play a role in spreading the novel coronavirus. (Read the document on ‘Aerogenic spread of SARS-CoV-2 and ventilation systems’ – only in Dutch). It seems as though the virus may be in the small aerosolised droplets, but that the dose of virus in these smaller droplets is usually not enough to infect someone, except in very high concentrations, such as when ventilating a COVID-19 patient in intensive care. The clearest indication for this is the reproduction number (R0) for the novel coronavirus. This number indicates how many people will be infected by a sick person without any preventive measures. The novel coronavirus has a reproduction number between 2 and 4. Diseases that spread through tiny droplets and remain ‘suspended’ in the air for a long time have a higher reproduction rate. Well-known examples include tuberculosis and measles. A person who has the measles virus will infect about 17 other people (without measures such as isolation or vaccination).
Athletes and musicians
It is not yet known whether sports activities increase the spread of the virus, for example because vigorous exercise produces more droplets. The same applies to musicians who play wind instruments, and to choral singers. Sports and singing certainly do release big droplets, similar to shouting and talking, but not as much as coughing or sneezing.
It also seems unlikely that the novel coronavirus is spread via parcels or surfaces (such as a door or shopping cart). Although it has been demonstrated in the laboratory that this is possible, that experiment was done under ideal conditions that will rarely occur in actual practice. The most important thing is: minimise your risk and wash your hands regularly.
How to prevent the novel coronavirus from spreading
- Wash your hands often with soap. This will remove the virus from your hands, making it harder to infect yourself or others.
- Avoid touching your face with your hands as much as possible. This reduces the risk that you will become infected if you have the virus on your hands, and makes it less easy for you to infect others.
- Cough and sneeze into your elbow, to keep the virus off your hands.
- Use paper tissues to blow your nose and discard them after use.
- Do not shake hands. Avoiding hand contact makes it harder for the virus to spread via hands.
- Stay 1.5 metres (2 arm lengths) apart from others. This makes it harder for the virus to spread via (accidental) coughing or sneezing.
- Work from home as much as possible. If people have less contact with each other, the virus cannot spread as easily.
- Avoid crowds and try to avoid travelling during rush hour.
The government has implemented measures to prevent the novel coronavirus from spreading. See the Dutch response and coronavirus measures
Questions about how the virus spreads
Can I become infected with the novel coronavirus from food?
When preparing food, it is important to always follow the hygiene measures. This prevents infections with all kinds of pathogens, such as salmonella. There is no evidence that the virus spreads through eating or preparing food. Also, coronaviruses need a living animal or human to grow and reproduce, in contrast to bacteria such as Salmonella. That means that the novel coronavirus cannot grow in food.
Can the novel coronavirus spread through glasses, crockery or cutlery?
It is possible to contract an infection involving bacteria or viruses via surfaces. The chance of getting a glass that has been used by someone that is currently shedding the virus is small right now. This is because people with symptoms have to stay home. The risk of contracting the virus by drinking from a glass that has been used by someone who does not have any symptoms yet, but still turns out to have the virus, is small, but present. To minimise that risk as much as possible, it is important to ensure that the glass is properly cleaned. The same goes for crockery and cutlery. In most cases, infection occurs via droplets from sneezing / coughing and via hands. For that reason, you should follow the current hygiene guidelines and measures which apply to everyone.
Can you get infected by using the shower or toilet area at such locations as a campsite / swimming pool?
The risk that the novel coronavirus will spread by using a communal shower or toilet at the campsite or swimming pool is minimal. The virus may possibly be present in faeces or urine, but there is no evidence of infection via a toilet.
The virus is transmitted through small droplets released when an infected person coughs and sneezes. If you are standing nearby and you inhale those droplets, or get them on your hands and then into your mouth, nose or eyes, you may become infected with the virus.
You should therefore stay at least 1.5 metres apart from others and wash your hands regularly with soap and water – including right before you leave the shower or toilet area.
Also, it is important that public toilets and shower rooms are cleaned regularly according to the general hygiene guidelines and that these indoor spaces are well ventilated.
Can I use a fan or air conditioning?
The page on Heat and COVID-19 offers an answer to this question and other questions about warm weather and COVID-19. Or take a look at the document addressing the role of ventilation in spreading the novel coronavirus (only in Dutch).
Is it safe to make music (e.g. singing or playing a wind instrument) with a band/choir/ensemble/music society?
There may be an increased risk of spreading the novel coronavirus if people sing or play wind instruments in a group setting. This possibility is still being investigated. A guideline is being drawn up for choirs and (amateur) singers in groups. Go to government.nl for more information about the measures and possibilities.
Can people pass on the novel coronavirus before they have symptoms?
The latest scientific insights (in Dutch) show that people may be contagious as soon as they develop the very first symptoms. Because those symptoms are sometimes very mild, it is unclear whether people are contagious even before they start showing symptoms. That is why contact tracing includes a patient’s contacts starting two days before the first clear symptoms.
What is herd immunity?
A person who has already had COVID-19 will probably be immune to the novel coronavirus afterwards. That means that this person can no longer become ill from this virus. The more people that are immune to the virus, the less the virus will be able to spread. This also reduces the risk that the virus will reach vulnerable people. Herd immunity (also referred to as group immunity) builds a ‘protective wall’ around vulnerable people.
Can I get infected by cigarette smoke from a COVID-19 patient?
Blowing out cigarette smoke is probably no different than exhaling normally. The risk of infection is therefore the same as the risk from a non-smoker. However, smokers may cough more than people who do not smoke. Regardless, people should stay 1.5 metres apart at all times to avoid infecting each other.
People who smoke should be aware of the increased risks. Smokers are more vulnerable to the novel coronavirus.
Can I have sex?
You can have sex with a steady partner. In the following situations, the advice is NOT to have sex:
- You have (mild) symptoms that may indicate the novel coronavirus. Are the symptoms getting worse? Then contact your family doctor.
- You have a confirmed COVID-19 infection and are in isolation.
- You are a household member or partner of someone with a confirmed COVID-19 infection or with (mild) symptoms.
- Have the symptoms been gone for 24 hours? Then you can have sex again.
Can you kiss your partner?
You can kiss your partner. However, you can contract the novel coronavirus from kissing, and pass it on to your partner the same way. If your partner has symptoms that could indicate COVID-19, then do not kiss. The advice to stay 1.5 metres apart from others also means that you should not kiss other people.