April 16, 2020
New preamble: The data is starting to look even better as 99.6 percent of us (that get infected) are going to see the year 2021. I like those odds better than what has been believed and projected to date.
The United States is definitely experiencing this pandemic in very regional ways. Major cities like NYC, New Orleans and Detroit are seeing the lion's share of the case fatalities and severity. Other states like North Carolina and many midwestern states are mildly suffering. This is likely primarily due to early and sustained exposure to travelers from across the globe to these crowded urban areas and also close
quarter events like Mardi Gras which amplify transmission for those that are asymptomatic viral shedders. These will be hard lessons learned for the urban centers moving forward. This is not the last pandemic and we need to be more prepared for the next one especially if it is a bad influenza type with a high CFR in young children.
From A Nature Medicine article yesterday: Abstract: We report temporal patterns of viral shedding in 94 patients with laboratory-confirmed COVID-19 and modeled COVID-19 infectiousness profiles from a separate sample of 77 infector-infectee transmission pairs. We observed the highest viral load in throat swabs at the time of symptom onset, and inferred that infectiousness peaked on or before symptom onset. We estimated that 44% (95% confidence interval, 25-69%) of secondary cases were infected during the index cases' presymptomatic stage, in settings with substantial household clustering, active case finding and quarantine outside the home. Disease control measures should be adjusted to account for probable substantial presymptomatic transmission. (He et. al. 2020)
This is inline with what many believed to be happening with the R0 as high as it seems to be for SARS2. There is a lot of asymptomatic or presymptomatic trtansmission occurring.
Opinion time: As the world moves more and more toward virtual events, this maybe another silver lining to be gained. When another outbreak occurs anywhere in the world, it makes prudent sense to shut down travel completely to this area and move business virtual. The problem is, as we saw in the COVID19 experience, if the virus has already jumped to Europe or another industrialized highly mobile country, then we are in trouble unless we expand the travel restrictions rapidly. It seems high time that the CDC and the WHO get more serious about real time tracking and testing rapidly when these events occur. We need nation states to sign on to rapid dissemination of data when an outbreak starts. There is sufficient concern that the Chinese governmental response was very questionable outside of genetic information sharing. A one week delay in action is a one week viral head start that allows a pandemic to travel and exponentially grow. What really transpired is hard to truly know. The next viral pandemic could be a real killer and our response this time was not adequate as a global community. This event was the wakeup call for national stockpiles of PPE, ventilators and products needed for testing. They should be sourced here in the United States to protect the supply chain. COVID19 has shown that infectious pandemics are a national security issue.
We may need to start treating SARS2/COVID19 as a seasonal event like influenza until a vaccine is developed or herd immunity materializes, assuming it does. The overall damage to the US economy this time may turn out to be far more negative and daunting than the virus itself but next time could be dramatically different for both our physical and mental health and the economy. National poverty and unemployment driven by a viral pandemic will have lasting repercussions on children's mental health and likely lead to countless adverse childhood events that we do not want. This is my pure opinion as a Monday morning quarterback pending further data.
Now back to the current data.
Latitude appears to be playing a role in which countries/regions are more at risk for viral spread and case fatality/infection rates. The University of Maryland has just published data that shows that the virus prefers the latitude ranges of 30 to 50 degrees on the globe (1 / 2). This is roughly the northern border of Florida west to San Diego, California and then the northern border of the United States. Essentially, the whole US carving out Florida. A friend recently shared some statistics with me: 95% of the infections are occurring between 22 degrees and 57 degrees North Latitude where roughly 60% of the world's population lives. The common denominator here is that SARS2 seems to like dry and cold air and not humidity. This may be the first glimpse that this coronavirus may have a seasonal activity predilection like influenza.
Let's look at some of the data discussed by Drs. Peter Attia and Amesh Adalja on the Drive podcast #106. Dr. Adalja is a pandemic infectious disease expert and states that the data is leaning strongly towards a case fatality rate between 0.3% and 0.66%. Germany's latest CFR is 0.37%. To put this into perspective again, seasonal influenza is an annual killer at 0.1%. The most recent influenza season to be severe was the 2017/18 season with 44 million or 13.5% of Americans were infected and 61000 deaths. (CDC data) We are currently at over 22000 deaths in the US from COVID19. Dr. Adalja states that hospitalization rates appear to be roughly 5% of known infected individuals. That means that if we add in the asymptomatic unknowns, hospitalization rates are very small nationally.
A recent analysis of pregnant women in NYC noted a huge asymptomatic group. From the NEJM correspondence piece: "Between March 22 and April 4, 2020, a total of 215 pregnant women delivered infants at the New York-Presbyterian Allen Hospital and Columbia University Irving Medical Center . All the women were screened on admission for symptoms of Covid-19. Four women (1.9%) had fever or other symptoms of Covid-19 on admission, and all 4 women tested positive for SARS-CoV-2. Of the 211 women without symptoms, all were afebrile on admission. Nasopharyngeal swabs were obtained from 210 of the 211 women (99.5%) who did not have symptoms of Covid-19; of these women, 29 (13.7%) were positive for SARS-CoV-2. Thus, 29 of the 33 patients who were positive for SARS-CoV-2 at admission (87.9%) had no symptoms of Covid-19 at presentation." (Sutton et. al. 2020)
As we get further and further down the rabbit hole we are realizing very quickly that SARS2 is a bad viral player but only marginally worse than the seasonally problematic influenza and much more contagious because so many individuals are asymptomatic shedders. One hard hit region in Germany is already showing a 14% immunity to the virus. (webpage) This is a great piece of information. They are 2 months into the disease spread and already hurtling toward herd immunity with a low CFR.
When antibody testing becomes the norm, we will likely realize that many of us have already been exposed, infected and immune. This will be a great realization for the rest of society. Once 60% of Americans are immune, then this disease moves towards a rare concern in small events, or so we presume. We will need to follow a subset of the population for the length of immune status. From a Science article this week, Dr. Kissler and colleagues at Harvard have a slightly different view. They write, "we used estimates of seasonality, immunity, and cross-immunity for betacoronaviruses OC43 and HKU1 from time series data from the USA to inform a model of SARS-CoV-2 transmission. We projected that recurrent wintertime outbreaks of SARS-CoV-2 will probably occur after the initial, most severe pandemic wave. Absent other interventions, a key metric for the success of social distancing is whether critical care capacities are exceeded. To avoid this, prolonged or intermittent social distancing may be necessary into 2022". (Kissler et. al. 2020)
Until we know which path to be true, we as a society will need to continue to be smart about our actions. Reducing direct contact, i.e. handshakes and hugs, will need to be the norm for a while. Self quarantining pending a COVID test result will be necessary. Avoiding high risk individuals in general is a great idea. Individuals over 60 years of age and people with cancer, hypertension, diabetes, obesity and other risk factors need to seriously consider staying quarantined for a while as it is hitting these groups hard.
Most importantly, we need to continue to follow the directives of the individuals with the most knowledge, the CDC.
It is just data sprinkled with some opinion,
Dr. M
SARS2 Severe adult respiratory syndrome coronavirus is the viral name
COVID 19 is the disease name
Sajadi SSRN article
Sutton NEJM Article
Kissler Science Article
He Nature Medicine Article
