The novel coronavirus, SARS-CoV-2, spreads easily from person to person. Understanding how long the virus lasts in the body, and how long it can stay alive on surfaces or in the air, can help prevent transmission.
This article explores the available research on how long the novel coronavirus lasts in the body and how long it remains active in various situations.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.
The novel coronavirus, SARS-CoV-2, is the virus responsible for causing the illness COVID-19. Most people who develop COVID-19 symptoms improve without treatment in 2–6 weeks. However, this does not necessarily reflect how long the virus itself remains active in the body.
COVID-19 has an incubation period, meaning it can be days before a person notices symptoms. In the case of SARS-CoV-2, a person can transmit the virus 48 hours before developing symptoms.
Many people experience mild symptoms, while some experience no symptoms at all. This can make it difficult to tell who has the virus.
How long the virus lasts in the body depends on the individual and the severity of the illness. The Centers for Disease Control and Prevention (CDC) advise that people who test positive for COVID-19 should isolate themselves for the following amount of time:
|No symptoms||10 days after a positive test|
|Mild or moderate illness||10 days after symptoms appear, and after 24 hours with no fever (without using medications)|
|Severe illness||Up to 20 days after symptoms appear|
These figures represent when a person is most at risk for transmitting SARS-CoV-2 to others.
However, the virus may remain in the body at low levels for up to 3 months after diagnosis. This may mean some people get a second positive test result even after they recover, although this does not necessarily indicate the virus is still transmissible.
As of October 2020, there is no evidence that a person with mild or moderate symptoms can transmit SARS-CoV-2 more than 10 days after the first positive test result.
How long do symptoms last?
Early in the COVID-19 pandemic, health organizations advised that, for most people, symptoms would last a short amount of time. However, since then, people have reported that their symptoms last much longer than this.
A July 2020 CDC report found that 35% of people who had mild cases of COVID-19 were not back to their usual state of health 14–21 days after testing positive. Among those aged 18–34 years with no chronic medical conditions, one in five had not returned to their usual state of health.
This suggests that, for some people, COVID-19 symptoms last longer than original estimates, even in mild cases. By comparison, over 90% of people with influenza, or flu, recover within approximately 2 weeks of having a positive test result.
People who require hospital treatment or who experience “long COVID” may also have longer-lasting symptoms. Long COVID, or post-COVID syndrome, is a name for a collection of symptoms that some people continue to experience months after their initial illness.
The symptoms of post-COVID syndrome can include, but are not limited to:
- severe fatigue
- trouble sleeping
- shortness of breath
- muscle weakness
- heart palpitations
- low-grade fever
- trouble concentrating
- memory lapses
- mood changes
- skin rashes
- nausea or vomiting
Researchers are still examining what causes long-lasting symptoms and how best to treat them.
A study from the New England Journal of Medicine investigated how long SARS-CoV-2 would survive on various surfaces, including plastic, stainless steel, copper, and cardboard. The findings suggest that the virus could survive for:
- 4 hours on copper
- 24 hours on cardboard
- 72 hours on plastic and steel
However, while researchers can detect SARS-CoV-2 on various surfaces under laboratory conditions, it is unclear if this corresponds to a risk of infection under normal circumstances.
A September 2020 study in The Lancet found that when researchers swabbed various surfaces in a major hospital in Italy, only one item of protective equipment tested positive for SARS-CoV-2. They conclude that, as long as people follow standard cleaning procedures, the risk of transmission from surfaces is low.
The study on surfaces also found that SARS-CoV-2 could survive in aerosol form for 3 hours. An aerosol is a fine mist of liquid suspended in a gas, such as air.
As the experiment ended after 3 hours, the total amount of time that SARS-CoV-2 survives in the air could be longer. However, some factors, such as air temperature and humidity, may also play an important role.
A June 2020 review notes that other coronaviruses survive for longer in colder, less humid air. This may mean SARS-CoV-2 will become a more seasonal virus in some climates. The study on surfaces also did not consider how the virus might travel through the air in everyday situations.
SARS-CoV-2 spreads via respiratory droplets, which are tiny drops of liquid that enter the air when a person coughs, sneezes, or talks. A May 2020 study found that loudly talking can emit thousands of these droplets into the air, remaining airborne for around 8–14 minutes in a confined space.
As speech droplets do not appear to remain airborne for very long indoors, a person’s proximity to someone with SARS-CoV-2 is an important risk factor for developing COVID-19.
Currently, there is no direct evidence a person can contract SARS-CoV-2 from food. The World Health Organization (WHO) state that coronaviruses need a live animal or human host to survive, and that they cannot multiply on food packaging surfaces.
The WHO suggest washing fruits and vegetables as normal and washing hands thoroughly before eating. People should also ensure they do not share cutlery or plates with those who may have COVID-19.
If a person believes they have symptoms of COVID-19, or they may have been exposed to the virus that causes it, they should self-isolate in their home and call a doctor. Do not visit a healthcare facility without calling ahead first.
According to the CDC, COVID-19 symptoms can include:
- shortness of breath
- new loss of taste or smell
- body aches
- nausea or vomiting
A doctor can determine if a person might have COVID-19, and if so, what to do next. If a person’s symptoms rapidly worsen, they should call 911 or their nearest emergency department.
Some signs of severe COVID-19 include:
- trouble breathing
- pain or pressure in the chest
- feeling confused
- inability to wake up or stay awake
- blue lips or face, which may appear white or grey in people with darker skin
The best way to prevent COVID-19 and stop transmission to others is to avoid exposure to the virus that causes it. The CDC recommend:
- washing the hands frequently with soap and water for at least 20 seconds
- using hand sanitizer containing at least 60% alcohol, if soap and water are not available
- avoiding touching the face, particularly the nose, eyes, or mouth with unwashed hands
- staying at least 6 feet, or 2 meters, away from people who are outside of a person’s household
- wearing a mask in public places, when around people from other households, or in situations where physical distancing is difficult
- covering coughs and sneezes with a tissue or the inside of the elbow, and disposing of used tissues immediately in the trash
- cleaning and disinfecting frequently touched objects and surfaces every day
People can transmit SARS-CoV-2 even if they do not feel sick, so it is essential to follow these guidelines at all times, wherever possible.
The CDC recommend that people wear cloth face masks in public places where it is difficult to maintain physical distancing. This will help slow the spread of the virus from people who do not know that they have contracted it, including those who are asymptomatic. People should wear cloth face masks while continuing to practice physical distancing. Instructions for making masks at home are available here. Note: It is critical that surgical masks and N95 respirators are reserved for healthcare workers.
The novel coronavirus, or SARS-CoV-2, is active in the body for at least 10 days after a person develops symptoms. In people with severe illness, it may last up to 20 days. In some people, low levels of the virus are detectable in the body for up to 3 months, but by this time, a person cannot transmit it to others.
There is currently no evidence the virus can survive in food, but early evidence suggests it may last several hours on copper, 24 hours on cardboard, and up to 72 hours on plastic and steel. However, this does not necessarily mean the virus detected on these materials can trigger an infection.
Scientists are still studying how long SARS-CoV-2 can last on surfaces and clothes, and how it can travel through the air. Following guidelines for cleaning, hand washing, and masks can help keep the risk of transmission low.