When is Covid contagious? How long you’re infectious with coronavirus and when you can test positive

The BA.2 sub-variant of Omicron is continuing to cause high Covid case numbers in the UK.

It comes at a time when restrictions have all but ended and the Government has scrapped the universal provision of free Covid tests.

The legal requirement to self-isolate after testing positive has also been dropped, with Boris Johnson instead asking people to exercise personal responsibility.

Here’s what you should do if you catch the virus, and how long you can be contagious for.

When are you most contagious with Covid?

For previous variants of Covid-19, such as Alpha and Delta, the World Health Organization (WHO) has said symptoms could begin to develop anywhere between two days and two weeks after infection.

However, the incubation period – the time between infection and symptoms appearing – for Omicron and its offshoots is believed to be much shorter: between three and five days.

Harvard University says: “People are thought to be most contagious early in the course of their illness.

“With Omicron, most transmission appears to occur during the one to two days before onset of symptoms, and in the two to three days afterwards. People with no symptoms can also spread the coronavirus to others.”

Health Secretary Sajid Javid said in December: “Recent analysis from the UK Health Security Agency (UKHSA) suggests that the window between infection and infectiousness may be shorter for the Omicron variant than the Delta variant.”

Data shows that the majority of people are no longer infectious seven days after beginning to experience symptoms or first testing positive, particularly when vaccinated, and the vast majority are no longer infectious after 10 days.

How long can you test positive for?

Most people will stop testing positive within 10 days of starting to experience symptoms, or receiving their first positive test.

However, it is possible to continue testing positive for weeks or even months after having the virus.

The good news is that even if you are continuing to test positive after a long time, it is highly unlikely you are actually contagious.

The Gavi Vaccine Alliance explains: “The time taken to test negative after contracting Covid-19 depends on the severity of the case, and also on the test itself.

“PCR tests that hunt out parts of viral genetic material (RNA in the case of Covid-19) in our bodies and amplify it so we can detect it are extremely sensitive and can even pick up the presence of few viral fragments. This is because fragments of viral RNA can remain in our bodies long after the infection is over and the virus has been cleared from our system.”

What are the symptoms of Covid?

The NHS now lists the following as official Covid symptoms:

  • High temperature or shivering (chills) – a high temperature means you feel hot to touch on your chest or back (you do not need to measure your temperature)
  • New, continuous cough – this means coughing a lot for more than an hour, or three or more coughing episodes in 24 hours
  • Loss or change to your sense of smell or taste
  • shortness of breath
  • Feeling tired or exhausted
  • Aching body
  • Headache
  • sore throat
  • Blocked or runny nose
  • loss of appetite
  • Diarrhea
  • Feeling sick or being sick

For most of the pandemic, only the first three symptoms above were listed by the NHS.

However, it added a further nine signs at the start of April, explaining: “The symptoms are very similar to symptoms of other illnesses, such as colds and flu.”

More on Covid-19

What should you do if you have Covid?

In England and Wales people are no longer legally required to self-isolate after experiencing Covid symptoms or testing positive. Scotland and Northern Ireland still have mandatory isolation in place.

However, the UK Government is continuing to advise people with Covid to stay at home and avoid contact with others.

If you test positive or experience symptoms, the NHS advises taking the following steps:

  • Try to work from home if you can – if you’re unable to work from home, ask your employer about options available to you
  • Stay at home if you can – this helps reduce the number of people you have contact with
  • Avoid contact with people at higher risk from Covid-19, especially if their immune system means they’re at higher risk of serious illness from Covid-19, even if they’ve had the vaccine
  • Follow advice on how to avoid spreading the virus to people you live with
  • Let people who need to come into your home know that you’ve tested positive or have symptoms – they can then take steps to protect themselves, such as wearing a face covering that fits well, staying away from you as much as they can, and washing their hands regularly
  • Contact your healthcare provider and tell them about your positive test result or symptoms if you’re asked to attend a medical or dental appointment in person
  • Ask friends, family or neighbors to get food or other essentials for you

If a child or person aged 18 or under tests positive they should try to stay at home and avoid contact with other people for three days. This starts from the day after they did the test.

Previously, people were advised to leave isolation after five full days if they tested negative two days in a row, or after 10 days if they were continuing to test positive.

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