COVID-19Common question

What does pre-symptomatic transmission of COVID-19 mean?

The incubation period for COVID-19, which is the time between exposure to the virus (becoming infected) and symptom onset, is on average 5-6 days, however can be up to 14 days. During this period, also known as the “pre- symptomatic” period, some infected persons can be contagious. Therefore, transmission from a pre-symptomatic case can occur before symptom onset.

When do you start being contagious with COVID-19?

A person with COVID-19 is considered infectious starting 2 days before they develop symptoms, or 2 days before the date of their positive test if they do not have symptoms.

What does presymptomatic mean in relation to COVID-19?

Presymptomatic means you're infected, and you're shedding the virus. But you don't yet have symptoms, which you ultimately develop. Unfortunately, the evidence suggests that you may be most contagious in the presymptomatic stage before you have any symptoms.

What is the difference between presymptomatic and asymptomatic cases of COVID-19?

A presymptomatic case of COVID-19 is an individual infected with SARS-CoV-2 who has not yet exhibited symptoms at the time of testing but who later exhibits symptoms during the course of the infection.

An asymptomatic case is an individual infected with SARS-CoV-2 who does not exhibit symptoms at any time during the course of infection.

What does it mean to be asymptomatic and pre-symptomatic for COVID-19 infection?

There has been a lot of news coverage about COVID-19 and asymptomatic and pre-symptomatic spread.
Someone who is asymptomatic has the infection but no symptoms and will not develop them later. Someone who is pre-symptomatic has the infection but don't have any symptoms yet.
Both groups can spread the infection.

What you should know about the coronavirus incubation period

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How long should I quarantine if I'm asymptomatic with a positive COVID-19 test?

If you continue to have no symptoms, you can be with others after 10 days have passed since you had a positive viral test for COVID-19.

If you develop symptoms after testing positive, follow the guidance above for “I think or know I had COVID-19, and I had symptoms.”

Can you get the COVID-19 from someone who has no symptoms?

Both flu viruses and the virus that causes COVID-19 can be spread to others by people before they begin showing symptoms; by people with very mild symptoms; and by people who never experience symptoms (asymptomatic people).

What percentage of COVID-19 transmissions are from asymptomatic cases?

In the first mathematical model to incorporate data on daily changes in testing capacity, the research team found that only 14% to 20% of COVID-19 individuals showed symptoms of the disease and that more than 50% of community transmission was from asymptomatic and pre-symptomatic cases.

What is an asymptomatic case of COVID-19?

An asymptomatic case is an individual who has a laboratory confirmed positive test and who has no symptoms during the complete course of infection.

How long can you spread COVID-19 after testing positive?

People with COVID-19 can spread the virus to other people for 10 days after they develop symptoms, or 10 days from the date of their positive test if they do not have symptoms. The person with COVID-19 and all members of the household should wear a well-fitted mask and consistently, inside the home.

How long should I wait to get tested for COVID-19 after being exposed if I am fully vaccinated?

- If you have been fully vaccinated and around someone who has COVID-19 (close contact), you do not need to stay away from others (quarantine), or be restricted from work unless you develop COVID-like symptoms. We recommend that you get tested 3-5 days after your last exposure to someone with COVID-19.

What does it mean that someone is asymptomatic?

Someone who is asymptomatic has the infection but no symptoms and will not develop them later. Someone who is pre-symptomatic has the infection but does not have any symptoms yet.

Why asymptomatic patients are more likely to spread COVID-19?

In fact, people who are infected may be more likely to spread the illness if they are asymptomatic, or in the days before they develop symptoms, because they are less likely to be isolating or adopting behaviors designed to prevent spread.

How does COVID-19 mainly spread?

Spread of COVID-19 occurs via airborne particles and droplets. People who are infected with COVID can release particles and droplets of respiratory fluids that contain the SARS CoV-2 virus into the air when they exhale (e.g., quiet breathing, speaking, singing, exercise, coughing, sneezing).

What should you do if you have been around a person with COVID-19?

For Anyone Who Has Been Around a Person with COVID-19

Anyone who has had close contact with someone with COVID-19 should stay home for 14 days after their last exposure to that person.

Should I get tested for COVID-19 if I have no symptoms and I've been exposed?

Even if you don't have symptoms, you should get tested 3-5 days after your exposure. If you need help, health department staff can provide information about the best time to get a vaccine and resources for COVID-19 testing in your area. If your test result is positive, you have COVID-19 and should isolate for 10 days.

Should I get tested after a close contact with someone who has COVID-19 if I am fully vaccinated?

• If you've had close contact with someone who has COVID-19, you should get tested 3-5 days after your exposure, even if you don't have symptoms. You should also wear a mask indoors in public for 14 days following exposure or until your test result is negative.

Should I be tested if I have been in close contact with someone who has COVID-19?

If you have been in close contact with someone who has COVID-19, you should be tested, even if you do not have symptoms of COVID-19. The health department may be able to provide resources for testing in your area.

What should I do if I've been exposed to a person with COVID-19 and I have fully recovered from a COVID-19 infection in the previous 90 days?

Someone who tested positive for COVID-19 with a viral test within the previous 90 days and has subsequently recovered and remains without COVID-19 symptoms does not need to quarantine. However, close contacts with prior COVID-19 infection in the previous 90 days should:
• Wear a mask indoors in public for 14 days after exposure.
• Monitor for COVID-19 symptoms and isolate immediately if symptoms develop.
• Consult with a healthcare professional for testing recommendations if new symptoms develop.

How long do COVID-19 patients continue to shed the virus?

The duration of viral shedding varies significantly and may depend on severity. Among 137 survivors of COVID-19, viral shedding based on testing of oropharyngeal samples ranged from 8-37 days, with a median of 20 days.

When can you be around others after being severely ill with COVID-19?

People who are severely ill with COVID-19 might need to stay home longer than 10 days and up to 20 days after symptoms first appeared.

Are recovered persons with persistent positive test of COVID-19 infectious to others?

Persons who have tested persistently or recurrently positive for SARS-CoV-2 RNA have, in some cases, had their signs and symptoms of COVID-19 improve. When viral isolation in tissue culture has been attempted in such persons in South Korea and the United States, live virus has not been isolated. There is no evidence to date that clinically recovered persons with persistent or recurrent detection of viral RNA have transmitted SARS-CoV-2 to others.

Despite these observations, it’s not possible to conclude that all persons with persistent or recurrent detection of SARS-CoV-2 RNA are no longer infectious. There is no firm evidence that the antibodies that develop in response to SARS-CoV-2 infection are protective. If these antibodies are protective, it’s not known what antibody levels are needed to protect against reinfection.

What steps should you take after coming into close contact with someone who tested positive for COVID-19?

• Stay home for 14 days after your last contact with a person who has COVID-19.
• Watch for fever (100.4◦F), cough, shortness of breath, or other symptoms of COVID-19.
• If possible, stay away from others, especially people who are at higher risk for getting very sick from COVID-19.

Am I considered a close contact for COVID-19 if I was wearing a mask?

A person is still considered a close contact even if they were wearing a mask while they were around someone with COVID-19. You can call, text, or email your contacts. By letting your close contacts know they may have been exposed to COVID-19, you are helping to protect everyone.

Who is considered a close contact of someone with COVID-19?

For COVID-19, a close contact is anyone who was within 6 feet of an infected person for a total of 15 minutes or more over a 24-hour period (for example, three individual 5-minute exposures for a total of 15 minutes). An infected person can spread COVID-19 starting from 2 days before they have any symptoms (or, if they are asymptomatic, 2 days before their specimen that tested positive was collected), until they meet the criteria for discontinuing home isolation.