Q. We heard from a woman who had asymptomatic COVID-19, discovered through a test, who recovered and later tested negative. Then, after every other member of her family developed symptomatic COVID-19, she tested positive again. Had her virus gone dormant or was she reinfected?
A. “There are no confirmed reports to date of a person being re-infected with COVID-19 within three months of initial infection,” says the Centers for Disease Control and Prevention. But research is ongoing, and the CDC says that data shows that someone who has recovered from COVID-19 may have low levels of the virus in the body for up to three months after diagnosis. So if the person is re-tested within three months, they could test positive, even though they are not spreading the virus, the CDC says.
Because no two people react to COVID-19 the same way, the CDC lists a few different scenarios in their guidelines. If you test positive but show no symptoms, the CDC advises that you stay away from people for 10 days. If you test positive and show symptoms that include a fever, the CDC says you can stop self-isolating after 10 days IF you go three consecutive days without a fever and your symptoms improve. If you have symptoms but no fever, you can stop self-isolating after 10 days have passed since the symptoms first appeared and you are feeling better.
If you come in contact with a person with COVID-19, the CDC recommends self-quarantining for 14 days after that exposure.
According to Harvard Medical School, it is not clear how quickly someone becomes contagious after getting infected. They may be contagious 48 to 72 hours before starting to feel sick. Symptoms can take several days to appear, and usually appear within four or five days after exposure. It is believed people are at their most contagious early in the course of the illness, but they can still be contagious for up to eight days after feeling better.
The timing of the test is also important, according to Harvard. If you are tested on the day you were infected, your test result is likely to come back negative, because there are not yet enough viral particles in your nose or saliva to detect.
If you are having COVID-19 symptoms but get a negative PCR test result, there is no reason to repeat the test unless your symptoms get worse, according to Harvard.
When a person gets a viral or bacterial infection, a healthy immune system makes antibodies, which are proteins that make it harder for the virus to infect cells, to fight the infection. It is believed that the same will be true for the coronavirus, and that antibodies will offer protection against reinfection for at least two to three months, according to Harvard. People who have recovered from the coronavirus have antibodies in their blood.
A recent study compared the amounts of coronavirus in the nose, throat and lungs of both symptomatic and asymptomatic patients, and found that both types of patients had similar amounts of the virus in their bodies throughout the infection. Asymptomatic people are more likely to spread the virus, since they are unlikely to be isolating and/or wearing a mask around others.
Those infected are thought to be most contagious early in the course of their illness, especially if they are coughing and sneezing. People who test positive but don’t develop symptoms over 10 days are believed to be no longer contagious, but there have been some exceptions, according to Harvard. So some experts are still recommending 14 days of isolation after a positive test. To determine if you are no longer contagious, have to nasal or saliva tests 24 hours apart. If both are negative, you are no longer contagious.