in yesterday's Cycling Podcast, Jumbo DS Engels said that they were informed about the Kruijswijk positive during the night, and that a 2nd test was done in the morning. He didn't specify what kind of test those were, but RCS definitely did two of them. So I would assume that they handled it in the same way as for Yates?
I'm not sure they are following the same procedure as for Yates, although the Kruijswijk second test confuses the issue. In this article,
https://www.cyclingnews.com/news/si...talia-after-testing-positive-for-coronavirus/ , the procedure is described as a rapid test and then a PCR for Yates, but I think this might only be for people who present with symptoms during spot checks (temperature testing etc.) or who develop symptoms and request a test.
"Following the team's RACESAFE COVID-19 policy, he was isolated in his room and we immediately requested a rapid test using the services offering by the RCS [Giro organisation], which has returned positive."
The team reported that "a second, RT-PCR, test was later taken, which has confirmed the positive result"
In this article,
https://www.cyclingnews.com/news/mi...o-ditalia-after-four-positive-covid-19-cases/ , discusses the mandatory testing and only mentions a PCR test, no rapid testing.
Race organiser RCS Sport carried out a total of 571 tests on the riders and team staff at the Giro d’Italia. The testing was split across Sunday evening and Monday morning, with all the RT-PCR swab tests then sent to Milan for testing in a private laboratory. Further tests are due to be done on race staff on Wednesday.
My assumption would be that RCS protocols are rapid test when someone presents, followed up by PCR testing, and only PCR testing for the mandatory tests. This would make more sense, as the rapid tests are very likely to be biased towards specificity, so they're going to be more likely to return a false positive, and therefore need to be followed up with a PCR, but they do allow for fast results. PCR tests will need to be sent to a lab, so using these for those presenting may cause difficulties as you may not have any result back before the start of the next stage. If this is correct, it does mean there's a higher chance of someone being excluded from the race because their rapid test is positive and the PCR test hasn't come back yet, when they may actually be negative. I guess that's something they have to accept in this situation.
If this is the case, it only really follows that Sunweb carried out an additional PCR on Matthews, it would be ridiculous to use a less sensitive test when a more sensitive one has already returned a positive. Not all PCRs are equal, so there's a chance either one is wrong, and without knowing the specifics it's just guess work which is, or there's a chance he has been asymptomatic for a while and the first test picked it up but by the time of the second test the viral load was too low to measure. This second scenario could also explain two positive tests and the subsequent negative one.
Essentially we don't have enough information to make a hard conclusion, but the case does highlight some of the issues around testing, it's fallibility, and the risk riders are being asked to take. Many are no doubt assuming that testing is 100% accurate, or at least one form of testing is, with extremely low limits of detection, when this isn't the case. There's still a good chance riders and staff who tested negative are positive, either through inaccurate testing, or limit of detection depending where they are on the viral load curve.