To safely end the 2019/2020 season during the pandemic, the NBA created a special indoor campus in Orlando, where players were monitored by specialists, took tests daily and followed all precautions. The new study includes data on 3648 athletes living on campus.
If any of the players were diagnosed with an infection, he was immediately placed in isolation. The US Centers for Disease Control and Prevention (CDC) recommends quarantining for 10 days in the absence of symptoms. However, in 36 people (1%), the PCR test result was positive even after isolation, despite the fact that all of them tolerated the infection asymptomatically. One athlete has shed SARS-Cov-2 for over 100 days.
Doctors closely monitored these players and confirmed that none of them transmitted the infection to other athletes after being released from quarantine, although they were in constant contact with other basketball players, including without masks.
“Thus, our results support the observation that asymptomatic carriers who have been quarantined but have persistent positive PCR test results with high values do not appear to be infectious to those around them,” the study authors wrote.
In November last year, a major review of 98 studies was released, showing that the average duration of isolation of RNA from coronavirus is 17 days from the onset of symptoms in the upper respiratory tract, 14.6 days in the lower respiratory tract, and in feces – 17.2 days. In one case, the virus was isolated within 83 days. However, none of the studies found live viruses in tissues or secretions 9 days after the onset of symptoms. Thus, the peak of the viral load occurs in the first week of the disease, scientists say.
As the medical toxicologist, scientific journalist Aleksey Vodovozov told MedPortal, the long-term isolation of the virus may be due to several reasons.
“For example, a patient does have a virus. The specificity and sensitivity of modern tests is such that they catch a very small number of viruses. The second point is that PCR also reacts to “spare parts” of RNA, which may be from a “disassembled” virus. Immunity “disassembled” it, but PCR can react to it, we can detect them in the analysis. This does not mean that a person is sick or even a virus carrier. That is, a positive PCR does not mean that a person is contagious, ”said the expert.