Coronavirus cluster grows at Tokai University rugby club

Team sports should be drastically curtailed, if not cancelled. I live near a high school and baseball and soccer are going full swing.

During the endless training, with lots of loud, en-mass shouting-based chanting, which makes the US Marines seem like librarians. A recipe for mass infection.

We’ve all been this young and we know: Kids with this age are everywhere and deal with many different people on a daily basis - even during a pandemic.

I just wonder how the contact tracing is going with this one..

The higher the ct, the more likely you'll have positive tests.

That depends completely on not having proper controls, you can go up hundreds of cycles, so every single sample would have signal of amplification and you can still discard all the false positives thanks to the controls.

Anything on the same or higher CT of a known negative sample is discarded, any sample loaded in triplicate where the 3 CTs are different is discarded, anything with a melting curve that is not the same as the positive control is discarded. Current machines actually can do all these controls automatically. And that is even without including reactions done with at least two different sets of primers to eliminate recognizing similar sequences.

The importance of the news is not about the health of young, active athletes (that likely will not have any problem) but about how the disease spread so easily even with the controls that are supposedly in place to avoid it, so things have to change.

Overdeveloped muscles with underdeveloped brains...lol You can see that everywhere, any country, any kind of amateur and professional sports. Sports is continuing almost unrestricted while all other members of society try their upmost to abide to some rules and restrictions because of the pandemic. The strong signal of continuing the Olympics is an additional amplifying trigger not to care about anything. Don’t blame them, they just don’t understand anything of other fields like math, biology, virology , statistics and the like.

Tokai University said Sunday that 20 members of its rugby club tested positive for the novel coronavirus after 170 students and staff underwent polymerase chain reaction tests following an earlier outbreak.

Baseball and other professional sports persons having regular PCR testing workers in elderly homes, teachers, medical personels, supermarket, takyubin workers undergo zero testing and we are regularly reminded even here how Japan has handled this persistent virus than many countries.

Nobody died, nobody hospitalised, so that is the good news. Also good news is that they were tested and hopefully the spread will be contained.

Yet, how many have been hospitalized?

Yet how many do not want to be infected? That's the more practical question

Because that affects everything - if people do not want to be infected, the actions the school take are determined for that purpose

@Zoroto yes, so true, in fact 'mild' is a meaningless label in Japan, as it includes a wide range of outcomes, including people who experience difficulty breathing or a drop in oxygen saturation, not to mention gives no idea how many of them are still suffering symptoms weeks or months later. It has been established that initial illness is not a clear indicator of whether or not someone will suffer 'long covid', and we do not yet know whether this can result in permanent organ damage.

It is just a reflection of the supine media here, who just churn out publicly issued press releases that show interest in three things: the impact on the Olympics, the economy and the viability of the healthcare system. The cost of the pandemic in human suffering does not even figure in the reporting. So if these generally fit young althletes have infected parents, grandparents, neighbours, friends, fellow students, coworkers who then go on to suffer serious consequences is not even touched on in these stories.

Sports are going on, even in the pandemic.

Mike Tyson vs Roy Jones Jr...

UFC fights...

UFC is testing each fighter 3 or more times before the fights.

But all events are without spectators, and this kind of sport is no team sport.

And today in "Health" there is a report that the WHO said, people should do exercise, even in a pandemic. Otherwise a new pandemic can come up.

And look at the picture in that article. That picture says everything.

Yeah a Ct of 40 is quite high. Experts worldwide have complained about their countries setting the Ct too high. I think anything above 35 is meaningless.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185831/

That opinion is the result of not understanding the test and how it is performed, a primitive reaction controlled only by their Cts, which at this point nobody does. Your reference is also completely irrelevant, since even in their abstract they mention the conclusions apply only to their own protocol, that uses only one single primer set, different from the Japanese test that uses two (or even three) sets, each for a different part of the viral genome.

It is outside of a realistic possibility that a significant number of negative samples can give exactly the same CT for all the replicates in each of the reactions with all the primer sets, with the same profile in the melting curves while the negative controls remain unchanged. It does not matter if the reaction is run for 40, 80 or 200 cycles.

For all practical purposes the number of positives for the PCR reaction is reliable. Changing the number of cycles would not affect the rate of false positive reported.

Virus amounts that are irrelevant are not the concern. The positive outcome itself is meaningless because it is because the limit of reaction identification renders it so amplified below the amount that it is more likely to be from sequences that are not unique to the virus.

Well, there are many experts world-wide that are saying the same thing I am.

For reactions controlled by duplicates, negative controls and melting curve analysis? I don't think so, you would need a reference to prove that. I would not be surprising you completely misunderstood what you found, the same as the reference you brought here, that is completely unrelated to what you think it proves.

The problem is not virus concentrations that are irrelevant. What is irrelevant is the positive result itself and that is because the limit of detection of the reaction makes it so amplification below that level is more likely to be from sequences that are not specific for the virus.

To say it more simply. If putting whole RNA in the negative control gives amplification at cycle 38, and a virus titer of 1e2 gives amplification at cycle 42, a sample that contain both things would still be positive from cycle 38. Thus it is impossible to detect small amounts of virus derived RNA without becoming first a false positive. That is why for example nobody has ever published a protocol that could detect viral contamination of a patient (opposed to actual infection of that patient).

The whole point is that even if that amplification happens it can be discarded as a false positive thanks to the controls of the reaction. If you don't understand the reasons why you can be proved wrong it is better to understand those reasons first before saying they don't apply, because they do. This means that there is no reason to doubt that in general the people reported as positive are actually infected with the virus (or have been until recently) according with the evaluation parameters of the test. Having more cycles only increase the number of positives that are discarded as false, not the ones reported.

Interesting.

Two questions I believe articles like this need to do a better job of answering and sharing:

1) Of the 20, how many had symptoms? (And what were those symptoms?)

2) What was the cycle threshold (ct) used in running this PCR test?

The higher the ct, the more likely you'll have positive tests.

1) Of the 20, how many had symptoms? (And what were those symptoms?)

All 20 show no or mild symptoms. Overall I see it's been handled swiftly and properly.

2020/11/29 新型コロナウイルス感染者発生の報告について（東海大学）

https://www.rugby.or.jp/news/article/1096/

2) What was the cycle threshold (ct) used in running this PCR test?

The higher the ct, the more likely you'll have positive tests.

This technical question seems crucial and relevant though I don't yet know a clear answer. Should be more publicly addessed.

There is no official guideline in Japan while invidual testing agecies are said to set Ct at around 40. Some claim it's too sensitive, may give rise to a false positive result. In Taiwan, for instance, Ct is arranged at 35 while several European countries set it at around 40 (That variance suggests that you may test positive in Tokyo even though you test negative and walk free in Taipei).

A Nikkei's report summarises this point well;

PCR「陽性」基準値巡り議論、日本は厳しめ？

https://www.nikkei.com/article/DGXMZO65910480W0A101C2CE0000/

For the sake of top athletes qualified to attend key international events namely the Olympics, it is suggested that Ct numbers be agreed and standardized globally. Otherwise a possible false result could rob them of a full competition opportunity. I fear it's costly, even subject to lawsuits or international disputes.

All 20 show no or mild symptoms.

Great! So I guess some players caught a mild cold. Now they can continue playing without worrying about catching it.

There is no official guideline in Japan while invidual testing agecies are said to set Ct at around 40. Some claim it's too sensitive, may give rise to a false positive result. In Taiwan, for instance, Ct is arranged at 35 while several European countries set it at around 40 (That variance suggests that you may test positive in Tokyo even though you test negative and walk free in Taipei).

Yeah a Ct of 40 is quite high. Experts worldwide have complained about their countries setting the Ct too high. I think anything above 35 is meaningless.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185831/

That opinion is the result of not understanding the test and how it is performed, a primitive reaction controlled only by their Cts, which at this point nobody does.

Well, there are many experts world-wide that are saying the same thing I am.

Everything in your long posts about the PCR test (multiple primer sets, triplicates, controls...) only addresses the possibility of a spontaneous false positive. Nothing in what you have written addresses the problem with using a Ct of 40, which detects virus concentrations that are irrelevant. You're always saying that I (or others) don't understand, but if you actually understood the PCR protocol you could certainly do a better job explaining why we (me, others on this forum, and experts world-wide) are wrong.

Yet, how many have been hospitalized?