The Public Health Agency of Sweden
Updated 19 February 2020

Spread of infection

Spread of infection

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    The coronavirus causing COVID-19 (SARS-CoV-2) is mainly transmitted person-to-person via respiratory droplets. This means that the virus reaches the inside of your eyes, nose or mouth from droplets that are dispersed in the air when someone sneezes or coughs. The droplets fall to the ground within approximately one meter (3 ft) from the source.

    There are reports of transmission of COVID-19 from people without any symptoms of illness. However, only a few studies describe the role of this type of transmission in relation to the overall spread of COVID-19 in the community. Based on the available knowledge about COVID-19 and similar diseases, the current understanding is that this route of transmission represents a minor part.

    To reduce the spread of COVID-19 in the community, it is important to limit the transmission of the virus from people with symptoms of illness. This is one of the objectives of the Public Health Agency's ongoing efforts.

    Updated: 5/18/2020 1:41:15 PM

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    It is not yet clear how long the virus can survive outside the body. Research on related coronaviruses shows that they can live for several days on surfaces and items, under particular conditions. Their survival depends on temperature, humidity, and sunlight. Coronaviruses are sensitive to dehydration.

    The amount of virus particles present also determines how long a surface or an item is contagious. Such studies are done under controlled conditions in laboratories, and are not directly transferable to other environments, for example in the community.

    A recent study from a healthcare setting where patients with COVID-19 had been isolated shows that small amounts of genetic material from the virus can remain in the environment. Further studies will clarify the role of indirect contact transmission for the spread of COVID-19.

    It is important to maintain good hand hygiene. By washing your hands with soap and water you can decrease the risk of getting infected and infecting others. If water and soap are not available, alcohol-based hand rub can be used instead.

    Updated: 5/18/2020 1:41:52 PM

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    There is no data indicating that people have been infected from food or water. The coronavirus causing COVID-19 (SARS-CoV-2) is mainly transmitted person-to-person via respiratory droplets. This means that the virus reaches the inside of your eyes, nose or mouth from droplets that are dispersed in the air when someone sneezes or coughs. It is also unlikely that COVID-19 is transmitted via water in swimming pools or other types of baths.

    Wash your hands often with soap and warm water; before cooking and eating and after using the toilet. Alcohol-based hand rub is an alternative when you do not have access to hand washing facilities.

    More information is available from the Swedish Food Agency (in Swedish).

    Updated: 5/14/2020 1:19:32 PM

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    The virus causing the disease COVID-19 was most probably transmitted from animals to humans at a market with live animals in China. The possible animal source of COVID-19 has not yet been confirmed but research is ongoing.

    There is no evidence that the virus can spread from humans to pets.

    More information is available from the National Veterinary Institute, SVA (in Swedish).

    Updated: 5/14/2020 10:06:42 AM

  • Do I need to clean my house or handle household waste in any particular way?

    In a household where someone is ill with COVID-19 it is enough to clean as usual, using products available in supermarkets. Household waste, including paper tissues from infected persons, can be disposed of in your normal way.

    Updated: 3/20/2020 7:21:14 PM

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    Face masks are not needed in everyday life. The best way to protect oneself and others is to keep at a distance from other people and to maintain good hand hygiene.

    Read more here about how to protect yourself and others from transmission.

    Updated: 5/14/2020 9:12:45 AM

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    The scientific evidence around the effectiveness of face masks in combatting the spread of infection is weak, which is why different countries have arrived at different recommendations.

    Some countries have chosen to view face masks as a form of security and hope that universal use of face masks will reduce the risk of infection spreading from people who are in the incubation period, before the symptoms are apparent, or who have such mild or unspecific symptoms that they do not consider themselves ill.

    The Public Health Agency of Sweden does not recommend the general use of face masks, as a face mask that itches or slips down below the nose may mean a person is regularly touching their mouth, eyes or nose with their hands, which can increase the risk of the infection spreading.

    Use of a facemask may also encourage people with mild symptoms to go out into the community, which might increase the spread of infection.

    The Public Health Agency of Sweden is constantly assessing the state of knowledge in this area and reviews new information from various sources.

    Updated: 7/13/2020 12:46:38 PM

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    You should avoid using a fan or portable air conditioning  in any room where there are several people together, and in particular avoid directing the fan at groups of people.

    Viruses will normally only travel a short way through the air before they fall to the ground. However, if you have a fan on in a room, it is possible in theory for the fan to blow droplets containing the virus a longer distance.

    This may apply to COVID-19, although scientists have not looked specifically at how its virus particles are affected by fans.

    Therefore, the advice from the Public Health Agency of Sweden is that if there is a large group of people in the same place, they should not have a fan directed at them. However, a fan can be used in a room where there is only one person.

    Updated: 7/13/2020 12:47:29 PM

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    Our general guidelines state that people should maintain a physical distance from other people to reduce the risk of spreading COVID-19, particularly outside their immediate circles. Closeness, intimacy and sex promote well-being and a general good state of health. In a steady relationship, where people are already seeing each other and are close, sex is not precluded provided you or your partner/s are not showing any symptoms of illness. However, dating and casual sexual relationships with new partners put you at risk of being infected or of infecting others.

    Updated: 7/13/2020 12:49:23 PM