ORLANDO, Fla. (NewsNation Now) — A study last summer of National Basketball Association players and staff, as well as local vendors they interacted with, found that all 36 people who continued to test positive long after their COVID-19 symptoms subsided did not transmit the virus to anyone else.

The study, published Thursday in JAMA, was conducted while the NBA was playing in its “bubble” in the summer of 2020. The players were quarantined in Orlando, Fla. and did not have contact with anyone other than league personnel and the resort staff.

JAMA editors Dr. James Salazar and Dr. Mitchell Katz called this “an ideal experiment.”

The data shows 36 “persistent positive” individuals out of 3,648 people who were routinely tested. They define persistent positive as someone who tested positive, completed the CDC’s suggested quarantine, and tested positive again at least once afterwards. It could also mean someone who tested positive for COVID-19 antibodies while testing negative for the virus itself, only to then test positive sometime later.

One persistent positive case who had antibodies tested negative for 48 days before testing positive without symptoms. All but two of the persistent positive individuals were men.

They say those 36 people accounted for 1,480 “person-days of close-contact activities.” That means they could have been spreading the virus for a combined total of 1,480 days.

But, despite being involved in a close contact sport, none of them transmitted it to others.

“Our results support observations that asymptomatic individuals who have met CDC criteria for discontinuation of isolation, but who have persistent positive RT-PCR test results… do not appear to be infectious to others,” the study reads.

RT-PCR stands for reverse-transcription–polymerase chain reaction, which is regarded as the most accurate type of coronavirus test. It can be done via nasal swab or spitting in a tube.

The study was born out of a desire to know when someone who tested positive could safely end their isolation. In the beginning of the pandemic, the CDC recommended isolating until there were two negative PCR tests within 24 hours. In July 2020, they changed their recommendation to 10 days after symptoms began or a positive test, assuming the patient was feeling better.

The study’s authors say their findings back the updated recommendation.

However, there are caveats. The study says the players’ elite fitness makes it hard to apply the results to everyday Americans.

It also said the league’s COVID-19 protocols were almost too good to simulate normal life. Players and staff were tested daily, and anyone that tested positive was kept away from others for at least two weeks.

“These results should not be generalized to those who are immunocompromised or those with severe COVID-19 infections,” the study’s editor’s note says.