Falsehoods not Facts: Asymptomatic Spread
Recently Pandemic Data Analysis (PANDA) has started spreading "infobites" under the heading "Facts Not Fear". Here I address these and show how they are misrepresenting facts. Number 4/13 addresses asymptomatic spread of the virus.
PANDA quote Dr. Fauci:
In all the history of respiratory-born viruses of any type, asymptomatic transmission has never been the driver of outbreaks. The driver of outbreaks is always a symptomatic person.
They point to a source that essentially just has that quote but a source that gives the context is more useful. It starts at 43:58. He says firstly they'd like to see data that confirm asymptomatic transmission and then goes on to state the quote above.
Dr. Fauci later updates his estimates. In August 2020 he is quoted as saying:
Whereas when you have community spread, it's insidious. There are people who are spreading it who have no symptoms at all, and we know that definitely occurs. It's difficult to identify it, and it's difficult to do identification, isolation and contact tracing.
So clearly there had been updated information, but, PANDA insist on quoting Fauci's comments from January 2020. So technically they are correct, but this is very misleading as Fauci had updated his assessment as more information became available.
PANDA then says:
A systematic review and meta-analysis from 2020 showed that asymptomatic spread is not a key driver of disease. Asymptomatic ‘cases’ transmit a very low viral load, facilitating population inoculation, which is protective, rather than causing severe disease.
They refer to this article which states that:
Estimated mean household secondary attack rate from symptomatic index cases (18.0%; 95% CI, 14.2%-22.1%) was significantly higher than from asymptomatic or presymptomatic index cases (0.7%; 95% CI, 0%-4.9%; P < .001), although there were few studies in the latter group. These findings are consistent with other household studies28,70 reporting asymptomatic index cases as having limited role in household transmission.
A later study from January 2021 concluded that:
In this decision analytical model of multiple scenarios of proportions of asymptomatic individuals with COVID-19 and infectious periods, transmission from asymptomatic individuals was estimated to account for more than half of all transmissions.
This piece summarises multiple studies as follows:
All of these studies agree that AIC transmit SARS-COV2 to contacts, although to a somewhat lesser extent than SIC.
Not clear what a key driver would be but definitely important enough for many to study it.
The article referenced by PANDA does not support the statement that "asymptomatic ‘cases’ transmit a very low viral load, facilitating population inoculation, which is protective, rather than causing severe disease." They need to reference that if they believe it to be true.
PANDA then claims:
Testing and quarantining healthy people and preventing them from working or travelling is unscientific and must end.
This is clearly not supported by the evidence. It makes sense that testing and quarantining those that are infected (even without symptoms) can protect others because they can transmit the virus as confirmed by:
- Dr. Fauci himself.
- The article linked to by PANDA.
- And other studies.