By Arielle Dreher
The Spokesman-Review
State health officials are looking at about 100 cases of COVID-19 in state residents who have tested positive a second time with hopes they can learn more about reinfections..
They may face some roadblocks, however.
First, testing positive for COVID-19 and continuing to test positive for several weeks afterwards is possible. To date, a person who has had the virus and recovered could still have low levels of the virus up to three months after they were diagnosed, according to the Centers for Disease Control and Prevention, meaning they could continue to test positive even if they are not spreading the virus.
“We have heard about people who have tested positive and tested positive again, and (we) are in the process of writing up further protocol for further investigation that should be done on those individuals,” Lofy said.
To determine whether a person has become reinfected and not just tested positive again in connection with their first infection, health officials need access to each person’s samples (saliva or nasal swab samples) from both positive tests.
“In order to determine if it’s a completely new infection, you have to have the sample from the first time the person tested positive and compare the genetic material from the first and second tests,” Lofy said.
Thus far, getting access to the samples, if they are still at the labs at all, has been a challenge.
“A lot of labs are doing so many tests, they only hold those specimens for a certain period of time then throw them away,” Lofy said.
Lofy said the department is working with local academic partners as well as a CDC team to continue to study reinfection.
Researchers in Hong Kong found the first indication that a person could test positive for the virus again after already having it, according to a study published in August. Researchers found a man in his 30s who tested positive first in late March and then again in mid-August, 142 days after his initial symptoms set in.
Researchers ran a genome analysis on the man’s saliva samples taken during testing in March and in August. The two samples contained different strains of the virus, indicating his infection was likely new.
Lofy said there are about five case reports published of people getting reinfected with the virus thus far. There is still a lot left to learn, however.
“It appears people can get reinfected, but what we don’t know at this particular time is how often this could happen,” Lofy said, noting the large amount of questions still swirling about the virus and reinfection at this time.
Current CDC clinical guidance says that if a positive COVID-19 test occurs more than three months after a person’s symptom onset, that health care providers should consider the possibility of reinfection.
