Reader question: If I catch Covid and self-isolate for the required time period but then still return a positive test result after the allotted time, am I allowed to go out as normal?
If you are fully vaccinated, you must self-isolate immediately and carry out an antigen test on the fifth day after your symptoms appear or – if you are asymptomatic – after you took your positive test.
If the test result is negative and you have not had any symptoms for the last 48 hours you are free to leave quarantine.
However, if you do not do a test on the fifth day or the result is positive, you must continue to self-isolate until the seventh day after your symptoms began or after you took a test.
It is not necessary to do another test on this seventh day, and you may leave quarantine even if you still test positive.
In general, the medical research institute Institut national de la santé et de la recherche médicale (Inserm) states that a person becomes infectious two to three days before their symptoms begin, and is normally capable of passing on the virus until five to eight days after infection.
Test results will generally go back to being negative between five and 10 days after infection, as a person’s viral load drops, but some can remain positive for longer.
It is possible that you could still test positive for Covid up to two months after having had the virus, especially if you have a condition which means that your immune system is compromised.
However, test results are not always an indicator of how infectious a person is.
Positive results more than eight days after infection will often be caused by PCR or antigen tests detecting dead virus cells which can no longer infect anyone else, explained Pierre Tattevin, who leads the infectious diseases department of the Centre Hospitalier Universitaire in Rennes.
What are the rules for unvaccinated people?
Unvaccinated people must self-isolate and then take a test on the seventh day. If it is negative and you have not had symptoms for two days, you may leave quarantine. If not, you must continue to self-isolate until the tenth day.