Leaving quarantine before the full 14 days is up might not always be a good idea, as a new study shows that COVID-19 can still be passed on between 7 to 14 days after a person in a household falls sick. So, whenever possible, it is always best to stick to the full two-week quarantine.
If you live with someone or come into close contact with anyone who has COVID-19, the US Centers for Disease Control and Prevention (CDC) says you should stay home for 14 days. But there is a loophole that says people can come out of quarantine after 7 days if they receive a negative test result on day 5 or later.
However, new research suggests there is still some risk of the disease being passed on in the second week after their housemate first becomes sick. A new Morbidity and Mortality Weekly Report by the CDC studied 185 people who had household contact with someone infected with COVID-19. They found that one in five of these household contacts would become symptomatic or receive positive COVID-19 test results between day 7 and 14 after the person in their house fell ill, despite not appear to have the infection in the first week.
“Among persons exposed to COVID-19 in the household who were asymptomatic and had negative laboratory test results through 7 days after symptom onset in the index patient, 19 percent experienced symptoms or received positive test results in the following week,” reads the report.
In other words, it might seem like you avoided the virus in the first week, but you could still find yourself with the infection in the second week.
Of course, it’s hard to strike the right balance in regards to controlling the virus at a population level. While health authorities clearly want to reduce the spread of COVID-19 as much as possible, they realize that quarantining for two weeks might not be possible for those who need to get back to work or have other responsibilities. As such, they argue that people should be aware there is still a risk of leaving self-isolation after just 7 days.
“A shorter quarantine after household exposure to COVID-19 might be easier to adhere to but poses some risk for onward transmission. Persons released from quarantine before 14 days should continue to avoid close contact and wear masks when around others until 14 days after their last exposure,” the study authors conclude.
Generally speaking, it’s thought people with mild or moderate COVID-19 are no longer infectious 10 days after their symptoms first emerge. For severe COVID-19 cases, that rises to no longer than 20 days. It’s possible that some people may shed traces of the virus for up to 3 months after recovery, although they are in such small quantities, they are highly likely to make anyone else ill.
There are other extremely rare circumstances where a person might stay infectious for a surprising amount of time. A case study from November 2020 detailed a woman with leukemia who was infected with COVID-19 for at least 105 days and remained infectious for at least 70 days while remaining asymptomatic the entire time. However, this unusual case can be explained because the woman was immunocompromised and it’s highly unlikely to be a common problem.