April 20 2020
No, it is not.
The Phoenician: Birx (Dr. Birx) just claimed that flu doesn’t have asymptomatic cases and that they are basically unique to Covid-19. Wow! The question I asked you in our last podcast - I literally laughed out loud!
Dr. Why: I listened carefully what she had to say.
The question from a reporter was: “The University of Southern California in LA County … put out a report today that suggests that the penetrance of the virus is …. as much as 40 times what it was believed to be … that as many as 420,000 people in LA county may have been affected … which suggests two things … that suggest that you have a lot more people out there who could be spreading the virus … but it also suggests that the case fatality rate is more in line with the 2017-2018 flu than what we have seen in some other areas of the world … but I am wondering if you have seen that … what your thoughts may be?”
Dr. Birx answered: “So, we are looking at all of those studies very carefully and I think you will remember over the last three weeks I have been talking about the level of asymptomatic spread and … my concern about asymptomatic spread because … with flu and other diseases when people are sick it’s easy to contact trace … when people are not sick and shedding virus you have to have a very different approach … a very different sentinel surveillance approach of sentinel monitoring approach (Dr. Why: I feel like an English professor when I listen to this!) which we outlined in the guidelines and it is why the guidelines took that very seriously … we knew that was unique for respiratory diseases but it was because we were very concerned about the level of asymptomatic and … if you remember we used to … we talked about younger age groups may have more asymptomatic disease … and your asymptomatic disease may decrease with your older age groups and that your symptomatic disease might increase with age groups … this is still a working hypothesis … we have no data right now still to support that but it is these kind of studies that help … that we know that New York and Detroit and other cities are very interested which we want also support them in testing frontline responders first responders and health care workers because we think their exposure was the greatest…” She proceeded to elaborate that the tests are not very accurate and therefore we cannot trust them in general population….
Here is my take on this:
Dr. B failed to answer reporter’s question;
She proceeded to “trash” the tests as not sensitive and not specific enough outside of “first responders” population therefore implying that, studie(s) reporter eluded to, are not to be believed … because we do not know yet…;
She implied that “respiratory diseases” and “flu” in particular are somehow different from COVID-19, otherwise why would we act differently?
She did acknowledge the importance of contact tracing;
The truth is:
Asymptomatic carriers play an important role. As many as 50% of infections with normal seasonal flu may be asymptomatic, which may in part be due to pre-existing partial immunity;
Asymptomatic patients shed virus and can transmit the disease, but not at the same rate as symptomatic individuals, which creates an invisible “reservoir” for the virus;
The implication of this is that public health disease containment measures and infection control measures, alone, may slow but cannot stop a flu epidemic;
The typical incubation period for influenza is one to four days (average two days) The time between onset of illness among household contacts among whom transmission has occurred (termed the serial interval) is three to four days;
This is shorter than incubation period for SARS-CoV-2 which is claimed to be up to 14 (or even 21) days, although most people get sick within 5 days;
It does not change the fact that asymptomatic spread exists in both infections;
In a small influenza transmission study, the secondary attack rate was 25 percent among healthy individuals who socialized for 30 hours over a two-day period with volunteers who had been infected with influenza via intranasal drops;
Duration of shedding — in otherwise healthy adults with influenza infection, viral shedding can be detected 24 to 48 hours before illness onset. The average duration of shedding was 4.8 days (95% CI 4.3 to 5.3 days). Shedding ceased after 6 or 7 days in most studies but occurred for up to 10 days in some;
Among secondary influenza infections in the household setting, the duration of viral RNA shedding was shorter and declined more rapidly in asymptomatic and paucisymptomatic infections than in symptomatic infections;
Longer periods of shedding can occur in children, older adults, obese adults;
In one study, immunocompromised patients shed virus for a mean of 19.0 days, whereas immunocompetent patients shed virus for a mean of 6.4 days;
Among 147 inpatients >16 years of age with H3N2 influenza A infection, systemic glucocorticoid use and comorbidities such as chronic lung disease or diabetes were associated with slower viral clearance;
In a study that evaluated eight immunocompromised patients (seven with hematologic malignancy) who had shedding of influenza virus for ≥2 weeks (median 30 days), lymphopenia was associated with prolonged shedding in all patients.
Got the point?
If not, Dr. Why’s conclusion:
Although finite differences between influenza virus(es) and SARS-CoV-2 virus might exist, it does not change the fact that both infections have a large (>50%) number of asymptomatic cases. Why are we treating these differently? When was the last time we implemented a lockdown in an influenza epidemic?
The answer is NEVER!
The really good news is that there are lots of infected people walking around which means:
Case fatality ratio is low, and;
Herd immunity development is in progress.