It is hard to believe that we have been living our COVID-19 lives only since
about last March. It has been a shade over six months, but it seems so
much longer than that. As I pause to reflect on our shared journey over
that time, the first two words that come to mind are “pride” and “humility.”
I mean pride in the positive sense: that which is earned and justified.
Humility reflects how far we yet have to go.
But first, the recent numbers. There is little drama here this week, and
let us all hope it stays that way. Most of the national and state numbers
are improving. Regarding our Houston regional specific numbers, please
refer to prior
posts for a more complete explanation of the key TMC metrics. In short, our
R(t) value (the estimate of viral infectivity) is down below 1.0 again, which
is good. New case rates in Harris and surrounding counties are slowly
drifting down, albeit more slowly than anyone would like. Recall, we want
this number to be less than 200, about one fifth of its current level.
These two data points demand a word of caution: The R(t) and new case
numbers are not independent variables, and both are impacted by data reporting
issues from the state. I do not yet have confidence in the validity of
these two metrics. The reporting backlog seems to be improving, but there
are still open questions as to when a new case is added into the state’s
database (Date of specimen collection? Date of data entry?), and how duplicate
entries are managed.
The TMC’s third monitoring metric – test positivity percentage – currently sits
at goal at 5 percent and this is a reliable number as it is based on data
directly flowing from TMC institutions. Harris County’s positivity rate
is also trending down, currently at 9.5 percent. Test positivity rate is
a very rough estimate of disease incidence in the community. In order to
reopen schools and relax other restrictions, we need to have a low disease
incidence (rate of appearance of new disease) and prevalence (total amount of
disease in the community at any given time).
For the past couple of weeks, I have started to focus on the TMC new COVID-19
hospitalizations. From a high of about 360 admissions per day in early
July, this dropped to 88 per day two weeks ago, but inched up again last week.
It now appears to be trending back down again. Keep your eye on
this number if you are looking for a “Labor Day” effect. Recall, viral
exposure leads to a sequence of events. The virus incubates in the respiratory
tract. In at least some people it produces disease severe enough to
require hospitalization. This process from exposure to hospitalization
takes on average 7-14 days. I will be very curious to see what the new
hospitalizations are on Sept. 21, and if they are rising or falling. I
predict they will be higher. Fourteen days after Memorial Day, we saw an
increase in new community cases of about 65 percent (from 285/day to 470/day),
and they kept on growing from there. New hospitalizations were not far
behind. Two weeks after July 4th, new cases increased by an almost
identical percentage (64 percent from 1400/day to 2300/day).
In retrospect, things started to improve from mid-July forward. It is a
shame we cannot rely on the new community cases data, as this is probably our
best canary in our coronavirus coal mine, but watch the new hospitalizations.
If they are trending up, we could be headed for another disease surge.
Perhaps – hopefully – enough people have embraced masking, distancing and
safe practices at this point that it will dampen the Labor Day impact.
All projections are dicey. Like trying to predict if Hurricane Laura will
hit Houston, there is no simple model, and things can change quickly. We
all crave certainty, which no one can offer at this point. Which brings
me back to the theme of humility. But first, pride.
If you step back and reflect on the expansion of SARS-CoV-2 (the pathogen) and
COVID-19 (the disease) related knowledge over the past 6 months, it is stunning
– almost explosive. In very rapid fashion, we – scientists and clinicians
– have learned a ton about the basic genetics, lifecycle, evolution and
structure of the disease. The cellular binding receptors have been
identified, and we have some understanding of the human body’s complex and
variable response to infection. We have a well-defined understanding of
the course of the disease, and we have developed partially effective treatment
protocols and novel drug therapies. We are well down the path of
developing multiple vaccines, while systematically assessing their safety and
efficacy. We are beginning to understand the long-term complications of
the disease. And – notably – we have accomplished this while keeping
providers safe. For all our failings, and recognizing many things could
have gone better, we should be proud. Our research and care delivery
system performed admirably.
However, there is a consequence to this rapid growth of knowledge. Dr.
Charles Burwell, a former dean of the Harvard Medical School, in an address
famously told a class of new medical students, “half of what we are going to
teach you is wrong, and half is right. Our problem is that we don’t know
which half is which.” So it goes with COVID-19 knowledge. What we
think we know today may prove wrong tomorrow. Treatments that seem
promising in case reports, case series and meta-analyses fail to demonstrate
benefits in randomized controlled trials. New basic science discoveries
will drive the development of treatments not yet contemplated. This is
not a flaw in our system – it is our system working as intended and working
very well.
Now, humility. SARS-CoV-2 has humbled us along the way. As we
contemplate returning children to face-to-face classrooms, one great example of
how our knowledge has evolved relates to how the virus impacts children.
In the few months we have been battling this pathogen, the thinking on
involvement in children has changed dramatically.
When COVID-19 first appeared on the scene, the common thinking was that
children were not really susceptible to infection. They rarely contracted
the disease, and if they did, it was usually mild.
Very shortly thereafter, it was discovered children with COVID-19, as a delayed
complication, may develop a condition resembling Kawasaki’s Disease,
a rare disease of unknown etiology that results in diffuse inflammation
throughout the body and is a significant cause of acquired heart disease in
children. Although still rare, COVID-19 could no longer be considered an
entirely benign pediatric condition.
Weeks later, the thinking evolved. Children were contracting COVID-19,
and being hospitalized, with the most severe cases unfortunately rivaling the
adult experience. However, the severe cases seemed to be mainly confined
to obese adolescents.
More recently, data
from a sleepover camp in Georgia showed COVID-19 spreads with surprising ease
among children of all ages (campers were aged six and above).
Finally, today. It is clear children do contract COVID-19. The American
Academy of Pediatrics summary of state
reporting data on children clearly indicates children become infected with
the virus (over 476,000 cases to date, almost 10 percent of the total
number of documented infections). However, thankfully, hospitalizations
and death are uncommon. The risk of spread from asymptomatic children to
adults remains unsettled.
Now as we contemplate returning tens of millions of children to school –
an educational, emotional, social and economic imperative – think about the
above evolution and how reasonable recommendations may have changed from then
to now, based on what we thought we knew. Early on, it might have been
rational to reopen schools with minimal precautions. Based on current
knowledge, we need to plan cautiously, with adequate protection for children,
teachers and staff. We also must consider and manage the risk to
vulnerable adults living with school age children.
There are other examples of how knowledge has evolved. From “don’t wear
surgical masks, we need to save them for health care workers and first
responders” to “everyone should be wearing a cloth mask.” We used to
think transmission from inanimate objects was a significant risk. It is
now clear this is not a major mode of transmission (you should still wash your
hands regularly, and keep them away from your face). I will repeat.
The evolution of evidenced-based guidelines is not a flaw in our system –
it is our system working as intended.
We need to balance these two sides of our coin: pride and humility.
By embracing both, other virtues follow. We will have the
confidence to move forward, making timely decisions with incomplete
information. We will have the maturity to change our practices and
behaviors as new evidence emerges. Importantly, we will display charity
and patience with leaders in our civic, medical, educational and business
communities who are acting in good faith to protect people and mitigate the
impact of this novel global disaster.
Stay well.
James T. McDeavitt, M.D
(Here is a link to today’s message: https://bit.ly/32fT2hT.
Please feel free to share and post)
(Note: Between June 2020 through November 2021, I
wrote weekly COVID-19 pandemic updates seen through the lens of a health
sciences university. My intent was to
provide reliable information, acknowledge legitimate concerns, console, and
encourage. Each posting reflects issues
our community was experiencing at that moment in time. I have reproduced selected examples on this
site).
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