When are you most infectious with COVID?

A large-scale review of 113 studies of COVID-19 from 17 countries found that if you have COVID-19, your infectiousness is highest 1 day before the start of your symptoms and begins to wane about a week later for most people. The review included several COVID-19 variants that emerged before Omicron, including Delta.

What is the incubation period for COVID-19?

People with COVID-19 have reported a wide range of issues from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus.

How long does it take to show symptoms after you have been exposed to COVID-19?

Symptoms may appear 2-14 days after exposure to the virus. If you have fever, cough, or other symptoms, you might have COVID-19.

How long are you contagious after being sick with COVID-19?

Most people with COVID-19 are no longer contagious 5 days after they first have symptoms and have been fever-free for at least three days.

Is presymptomatic transmission of COVID-19 possible?

The possibility of presymptomatic transmission of SARS-CoV-2 increases the challenges of COVID-19 containment measures, which are predicated on early detection and isolation of symptomatic persons.

What to do if I have COVID? Treatment

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.

How long should I stay in home isolation if I have a COVID-19 infection?

Positive. The test detected the virus and you have an infection. Stay home for at least 5 days and isolate from others in your home.

Tell your close contacts. Wear a well-fitted mask when around others. If available, a N95 or KN95 respirator is recommended. Watch for symptoms.

How long do I need to stay in isolation if I have symptoms of COVID-19 but my symptoms are better?

If you continue to have fever or your other symptoms have not improved after 5 days of isolation, you should wait to end your isolation until you are fever-free for 24 hours without the use of fever-reducing medication and your other symptoms have improved.

How long do I need to stay isolated if I test positive for COVID-19?

If you test positive, you should isolate for at least 5 days from the date of your positive test (if you do not have symptoms). If you do develop COVID-19 symptoms, isolate for at least 5 days from the date your symptoms began (the date the symptoms started is day 0).

What 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).

What are some of the first symptoms of COVID-19?

Early symptoms reported by some people include fatigue, headache, sore throat or fever. Others experience a loss of smell or taste. COVID-19 can cause symptoms that are mild at first, but then become more intense over five to seven days, with worsening cough and shortness of breath.

What are some of the most common presenting symptoms of COVID-19?

Initial presentation — Among patients with symptomatic COVID-19, cough, myalgias, and headache are the most commonly reported symptoms. Other features, including diarrhea, sore throat, and smell or taste abnormalities, are also well described (table 3).

What should I do if I've been exposed to a confirmed case of COVID-19 if my vaccine is not up-to-date?

Stay home and quarantine for at least 5 full days. Wear a well-fitted mask if you must be around others in your home. Do not travel. Even if you don't develop symptoms, get tested at least 5 days after you last had close contact with someone with COVID-19.

How long after COVID-19 isolation should I wear a mask?

During the 10 days after infection, persons might be infectious to others and are recommended to wear a well-fitting mask when around others, and to avoid contact with those at elevated risk for severe disease, even if ending isolation after 5 days.

What do I do if I have mild symptoms of COVID-19?

If you have milder symptoms like a fever, shortness of breath, or coughing: Stay home unless you need medical care. If you do need to go in, call your doctor or hospital first for guidance. Tell your doctor about your illness.

Do I need to isolate if I have symptoms but I have been vaccinated for COVID-19?

People who are confirmed to have COVID-19 or are showing symptoms of COVID-19 need to isolate regardless of their vaccination status. This includes: People who have a positive viral test for COVID-19, regardless of whether or not they have symptoms.

How long does isolation take after COVID-19 infection if you were severely ill or have a weakened immune system?

CDC recommends an isolation period of at least 10 and up to 20 days for people who were severely ill with COVID-19 and for people with weakened immune systems. Consult with your healthcare provider about when you can resume being around other people.

How long should I quarantine after COVID-19 exposure if I am vaccinated?

Quarantine: If you have received all vaccine and booster doses recommended by CDC, you do not need to quarantine. You should wear a well-fitting mask around others for 10 days from the date of your last close contact with someone with COVID-19 (the date of last close contact is considered day 0).

At what point after infection with COVID-19 will there be enough antibodies to be detected in an antibody test?

After infection with the COVID-19 virus, it can take two to three weeks to develop enough antibodies to be detected in an antibody test, so it's important that you're not tested too soon.

Antibodies may be detected in your blood for several months or more after you recover from COVID-19.

Can I have COVID-19 if I have no symptoms?

It is good that you have not noticed any symptoms. It can take between 1–14 days for COVID-19 symptoms to show up, and in some instances, people with COVID-19 do not show any obvious symptoms, but they can still spread the virus.

How many COVID-19 patients are asymptomatic?

The South Korean estimate of 30 percent is slightly lower than the asymptomatic figure offered by Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. He said roughly 40 percent of Americans with COVID-19 are asymptomatic.

What is asymptomatic transmission?

An asymptomatic laboratory-confirmed case is a person infected with COVID-19 who does not develop symptoms. Asymptomatic transmission refers to transmission of the virus from a person, who does not develop symptoms.

There are few reports of laboratory-confirmed cases who are truly asymptomatic, and to date, there has been no documented asymptomatic transmission. This does not exclude the possibility that it may occur. Asymptomatic cases have been reported as part of contact tracing efforts in some countries.

What are some examples of mild illness of the coronavirus disease?

Mild Illness: Individuals who have any of the various signs and symptoms of COVID-19 (e.g., fever, cough, sore throat, malaise, headache, muscle pain, nausea, vomiting, diarrhea, loss of taste and smell) but who do not have shortness of breath, dyspnea, or abnormal chest imaging.

Can the Omicron variant cause long term COVID-19 symptoms?

The possibility of long COVID. While omicron may cause less severe symptoms, this may not mean a decreased risk of long-term sickness.