If you are at home with COVID, you may be wondering how long you are actually contagious. You don’t want to be isolated for longer than necessary, but you also don’t want to risk the health of your friends and workmates — or the health of vulnerable strangers for that matter.
In Australia, people with COVID are required to self-isolate for seven days unless they have significant ongoing or new symptoms (then the fine print in state and territory regulations says they should be given more time). should stay away).
So, what’s the risk of leaving the house after a week and still being contagious?
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What does the research say about the infectious period of Omicron?
Omicron’s incubation period – the period from becoming infected to acquiring symptoms – is about three days, with a person often becoming infectious for a day or two before symptoms emerge.
The average duration of Omicron symptoms is also significantly shorter – often 5–6 days, compared to 7–10 days with Delta and earlier variants. Omicron is more contagious because the increased number of mutations on its spike protein makes it better able to evade the body’s immune system.
It appears that the Omicron variant causes milder illness and more asymptomatic infections, and is better able to trick our immune systems – so a higher rate of success cases should be expected with the Omicron variant.
What if I still test positive on day 6 or 7 of the RAT?
Data from the Omicron outbreak suggest that rapid antigen tests (RATs) may not detect COVID until at least two days after exposure to the virus.
And the Therapeutic Goods Administration (TGA) says RATs aren’t as accurate if you don’t have symptoms. So it is likely that you will not test positive on the RAT until a few days after exposure. And, if you don’t have symptoms, you may get false negative results in the days to come.
PCR tests are likely to detect virus before RAT because of the high sensitivity, and PCR will also continue to detect virus particles for a longer period of time. Based on this test, the period of isolation can be extended even if the person is not infectious. That said, a PCR test is still considered the “gold standard” for detecting SARS-CoV-2 infection.
Most states don’t require a clear RAT or PCR test to be released from isolation, but say those who still have some symptoms (such as sore throat, cough, shortness of breath or runny nose) should have their own The separation should expand. If you have symptoms and you take the RAT test, a positive result may indicate that you are still contagious to others.
The goal of COVID testing is to identify people who are currently transmitting the virus. Therefore RATs are able to detect the vast majority of infectious cases and they work well in mass settings such as long-term care facilities, workplaces or schools.
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Meanwhile, emerging science (including data) [National Basketball Association’s extensive COVID testing program] Turns out that, even with the Omicron version, more than half of those infected may still be contagious at five days (the end of the recommended isolation period in the United States) — and possibly beyond.
In Australian states and territories, isolation is for seven days, provided the person has no symptoms.
It has been suggested that it may be safer to isolate for eight days and wear a mask to protect others for a total of ten days. In the northern region, those coming out of isolation are asked to wear masks for an additional seven days. People in South Australia have been asked to wear masks for three days after isolation.
What about the mask after that?
Therefore, people are likely to be infectious even after seven days of isolation if they are still symptomatic. After ten days, most people are no longer contagious. Several studies have shown that after the tenth day there is little, if any, transmission, regardless of the type.
However, for those who are immunised, it is recommended to wait 20 days to exit isolation as it has been shown that such patients leave the virus for longer.
AAP Image/Bianca De Marchi
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Once people have fully recovered from the disease and have no symptoms, they are considered non-contagious, as they have a very low virus load.
A person who has recently fully recovered from COVID does not need to wear a mask, as there is no risk for them to be re-infected with the same type. Accordingly, they do not pose any COVID threat to others.
However, they will need to reconsider this advice after 12 weeks, when re-infection is possible.
Your level of protection from vaccination or previous COVID infection can also depend on factors such as your age and immune status. It’s also worth noting that recovery from Omicron won’t protect someone from seasonal colds and flu or subsequent COVID variants – but a mask may.
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Take-home advice on when to leave the house
Protecting yourself and the community from infectious diseases, including COVID, depends on early detection of infection and the implementation of public infection prevention measures.
Until RAT tests are sensitive enough to definitively detect the absence of the virus, we need to supplement this test with preventive measures, such as isolating until symptoms subside, and indoor Wearing of masks in areas and at public events.
