NBA Study Shows Post-COVID Viral Transmission Rare, Even With Positive Test
FRIDAY, April 23, 2021 (HealthDay News) -- Isolated NBA players who recovered from COVID-19 but still tested positive for the virus didn't infect others after leaving isolation, a new study finds.
That someone who has had COVID can infect others has been a persistent fear, but these findings from the professional basketball league suggest that many who recover can return to contact with others without spreading the virus, researchers say.
"COVID-19 reinfection is possible, especially now with new variants, and every positive test should be taken seriously," said lead researcher Christina Mack of IQVIA, Real World Solutions in Durham, N.C.
This 2020 study, however, showed that sensitive tests such as RT-PCR may continue to yield a positive result after people have recovered from COVID. In the NBA campus setting, however, those folks were not infectious, Mack said.
To complete the 2019-20 season, the NBA set up a "bubble" in Orlando, Fla. -- a closed campus governed by scientific protocols to guard against COVID-19.
More than 3,500 people lived on the campus and were subject to its protocols. All had daily RT-PCR tests. Some had recovered from a previous COVID infection.
"These recovered individuals were not sick and were not observed to be infectious to others, but were instead shedding virus particles at a low level left over from their previous infection," Mack said.
"We observed that individuals could test positive up to 118 days after onset of infection, and that again, many of these individuals had tested negative on most of the days surrounding their positive test or tests," she said.
Among participants, 1% had persistent virus, most were younger than 30 and male. Antibodies were found in 92% of these persistent cases and all were asymptomatic. These people were monitored, and there was no transmission of the virus to others, the researchers reported.
Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City, wasn't part of the study but reviewed the findings.
"The results of the study support the premise that asymptomatic individuals who have met [U.S. Centers for Disease Control and Prevention] criteria for discontinuation of isolation, but who have persistently positive RT-PCR test results, do not appear to be infectious to others," he said.
This is an important finding and can help develop an approach to college and high school sports that is safe for players and athletic staff, Glatter said.
"The study also illustrates that a PCR test needs to have the degree of infectiousness attached in order to truly make an accurate assessment of COVID status and risk to others in the community," he added.
People whose infection values are high may have remnants of viral RNA but are not infectious and do not pose a risk to others, even with close contact as seen in the study, Glatter said.
Although PCR testing is the most accurate, he said rapid antigen tests may be a good alternative for gauging how infectious someone who recovered from COVID might be.
"Rapid antigen tests can be a valuable approach to detect an infection, since their utility increases with repetition, making them quite useful from a public health standpoint," Glatter said.
The study was published online April 22 in the journal JAMA Internal Medicine.
For more on COVID-19, see the U.S. Centers for Disease Control and Prevention.
SOURCES: Christina Mack, PhD, MSPH, IQVIA, Real World Solutions, Durham, N.C.; Robert Glatter, MD, emergency physician, Lenox Hill Hospital, New York City; JAMA Internal Medicine, April 22, 2021, online