Over the next few weeks we should getting some data that in aggregate will give us a better sense of how many have actually been infected but never even sick enough to think of it, let alone officially diagnosed, in areas that are beginning to approach their peaks. It is a subject that deserves its own thread as the data comes in, both to share the data and to discuss its implications.
It will be difficult to interpret though in the context of a curve that is not yet flat. Love to see it in China or South Korea Germany is planning to do similar widespread seroprevalence testing, but not until the end of the month.
Meanwhile testing everyone in one town for the virus and active infection tells us something too. Interpret the following with the knowledge that we do not know if those who have asymptomatic to very mild infections shed for as long as those who are more seriously ill or if they stop shedding in a significantly shorter period of time. The latter makes sense but would just be a guess. In the isolated Italian of village Vo’Euganeo, population 3000, apparently, they actually tested nearly everyone. Italy so still skewing older, but more of a complete sample than the Diamond Princess. The majority who were positive were asymptomatic.
I cannot verify that those who were tested and asymptomatic were followed to verify they stayed such. And again we do not know how long asymptomatic and minimally symptomatic people test positive relative to those more ill. So interpret with caution and as part of a hopefully soon to emerge aggregate of information. But it is something.
It’s possible that people who are asymptomatic are infectious for a similar period of time, but are not sneezing, coughing, or mouth breathing, so they shed a lot less virus.
As a person who believes I had a mild case several months ago, if I hear about any antibody studies, I will be more than happy to roll up my sleeve and give them some of my blood.
For how long were the “asymptomatic” describe above followed? Until we know this it’s hard to say who is pre-symptomatic and who is truly asymptomatic.
That nursing home study really gives me pause as to how high the true asymptomatic rate might be in the general (younger and healthier) population. Those with positive test results averaged 80.7 years old and had serious health problems. They counted 23 as positive test results but are not counting two who had been transferred to a hospital before testing for COVID-19 symptoms, so let’s use 25 as the better denominator. In THAT population 3/25, 12%, were asymptomatic and stayed asymptomatic. 12% of the highest risk group, sick disabled 80 year olds, had asymptomatic infections?! Wow.
From the ProPublica article your cite cites re China and true asymptomatic infections:
One, we should take information form China in February about asymptomatic cases with several grains of salt, even if they involved the WHO. Two, from a practical POV those who developed symptoms that were so mild that they completely dismissed them are functionally in the same bucket.
If the symptoms were so mild that they were completely blown off and changed nothing, then there is almost certainly confirmation bias in asking about it after the fact after diagnosing an illness that has been constantly in the news.
The asymptotic rate must be higher than reported, even leaving out the paediatric populace, perhaps, portending problematic prevalence probabilities.
I suppose the distinguished Qadgop is referring to the China coronavirus? Or maybe the Corelle virus, or the Smith-Corona? Any one of those can leave you pyrextic.
At the height of their testing in SKorea, they found 30% of those testing positive, had no symptoms.
(Testing, protocols, data, all high quality for this particular location is a plus!)
Yes but in South korea, about 3% of cases end in death and 97% end in recovery. Thats still pretty bad. Granted I"m sure they’re missing a lot of less clinical cases but thats one of the best tested nations out there and 3% of people still seem to die.
