Editor’s Note: Eric Schulze, MD, PhD is the chief executive officer of Lifetrack Medical Systems (LMS), a medical software and health tech company. Madhu Vijayan is the president of Calibrated Healthcare Network, a health-care information services company that focuses on the managed care population. The opinions expressed in this commentary are those of the authors. View more opinion articles on CNN.
The novel coronavirus, like all other viruses, has a specific biology based on its genetic material.
It expresses particular proteins that have a targeted point of entry into human cells, in this case the angiotensin-converting enzyme 2 (ACE2) receptor – and this has led to some very unusual biology.
Initially, to limit the spread of disease during this pandemic, the right approach was to use a blunt force instrument: the “sledgehammer” of population-wide community quarantine.
This gave scientists and doctors the time to study this virus and try to unlock its secrets. Now, after months of research, we know a little bit more about how this virus functions – and with emerging data – who is more at risk of falling seriously ill from the virus.
We are starting to understand why some people are at a higher risk from Covid-19, the disease caused by the novel coronavirus.
We may be able to use this knowledge to inform us how to start getting those who are at a lower risk back to work and normal life.
The comorbidity factor
Early on in the outbreak, the data started to show some unusual patterns. The virus could be deadly for the elderly but seemed uninterested in children. Additionally, hypertension was found to be one comorbidity, which is the simultaneous presence of two diseases or conditions in a patient. This is atypical for an infectious disease; for example, we don’t target people with hypertension as being at great risk for the flu.
Then, in March, a study from the Instituto Superiore Di Sanita in Italy revealed that 99% of coronavirus fatalities in Italy had comorbidities including diabetes, hypertension, cardiovascular, pulmonary, renal and hepatic disease or additionally having immunosuppression of any type. The study was the first to detail this connection.
The Centers for Disease Control and Prevention, based on preliminary US data, has reported that “persons with underlying health conditions such as diabetes mellitus, chronic lung disease and cardiovascular disease, appear to be at higher risk for severe Covid-19–associated disease than persons without these conditions.”
It was also noted that people over 60 were at much greater risk of dying than the young.
That age was a risk factor was not unusual as it nearly always is a risk factor – but age risk usually applies to both ends of the age spectrum.
Covid-19 affects young people ages 19 and under at significantly lower rates than other age groups. It was starting to seem that the elderly were more at risk because they had a higher prevalence of comorbidities. This explanation better fits the data and explained why so few young people were falling ill while the elderly were affected in greater numbers.
Age, it seemed, is not an independent risk factor, but rather an association.
Expanding our understanding
As we started focusing on these unusual epidemiological motifs through our practice and research, we were also starting to learn more and more about the cell and molecular biology of this virus, in particular its targeting of the human ACE2 receptor which allows it to enter into the cell.
This receptor is part of the body system that helps maintain normal blood pressure. Because this virus might do its worst damage to those organs most intimately involved in this system – namely the lungs, heart and kidneys – it is no surprise that it may target those patients with related diseases.
The preliminary incoming data continues to build on the thesis. A study of patients in New York City showed obesity to be a risk factor among individuals who sought medical attention at NYU Langone.
Another study at NYU found that among patients under 60, those with obesity were twice as likely to need hospitalization. A clear pattern seems to be emerging: not only does this virus appear to be targeting with diseases of the organ systems well known to be intimately related to ACE2 receptors, but it also seems to be targeting the obese where ACE2 can also be a factor.
Soon after the two of us started to suspect there was a connection between obesity and Covid-19, a paper from the UK Intensive Care National Audit Center (ICNARC) came out detailing the ICU experience for patients in the UK. The ICNARC report showed those with a Body Mass Index over 30, which is considered obese, made up 37.7% of the confirmed cases of Covid-19.
Its data was consistent with identifying obesity as a significant comorbidity for this virus, especially with respect to who is most at risk for needing ICU admission if infected.
To further punctuate this linkage, Professor Jean-François Delfraissy, the chief epidemiologist for France, also warned that overweight and obese people could be at risk.
In fact, given patient demographics in the US, this could be the most common of the comorbidities in the young as hypertension, cardiovascular disease, diabetes (adult onset) and chronic lung, kidney or liver disease are illnesses of middle aged and the elderly.
Applying what we know
A primary reason for the current global panic is that a consolidated approach to managing this pandemic has eluded us. While disparate groups have noted the presence of comorbidities, the scientific community has not made any unified conclusions so far.
Based on what we’ve been able to observe in patients so far, the at-risk population seems to be largely those with specific comorbidities related to the ACE2 receptor, including hypertension, diabetes, cancer, and cardiovascular and chronic lung, liver and kidney disease, as well as obesity.
Additional risk groups that have been identified are the immunocompromised for any reason. So, it is these vulnerable at-risk groups that we must take extra precautions to safeguard from this virus.
Considering the data, we can begin to think about this virus differently. It is not like the seasonal flu which broadly affects a population. Based on the information to date, we believe that this virus is more focused, which causes great concern, particularly for those in an at-risk group.
But we can also view the highly targeted nature of this virus as its Achilles’ heel. We are developing a sharper picture of who it is targeting and can begin to deduce who we as a society need to protect.
Rather than continuing to use a sledgehammer plan to defeat this virus, there may be wisdom in using a scalpel: a targeted approach that shelters the vulnerable and clearly delineates who is not at risk. This could create a path for reentry into normal life in a carefully structured manner.
Reviving the economy
If economic activity remains curtailed for an extended period of time, the impact will be felt by companies and local, county, state and federal governments. Countless employees have been laid off, businesses have been shuttered and in-person spending has all but halted.
Even when we are told that things are “normal” and that we can go out and spend money, if left for too late, the aggregate demand will simply not be there.
A mechanic, who has been out of work for months, upon finding work again will first focus on paying off his debts. Then he will focus on building up a bigger savings buffer than he thought he needed before. This means that he is going to take a long time to get back to being the same type of active consumer he was in January 2020. Multiply this reality across the income spectrum of working American families and it is clear that demand will take a while to pick up.
One can only speculate on the kind of burden this puts on the structure of society and the risks it exposes for the population.
At this point, instead of “flattening the curve,” – which is important to note does not save lives, it merely prolongs the time it takes for the vulnerable to get sick and die – it is maybe more prudent to specifically protect the vulnerable and keep them safe until we either have a vaccine or a cure.
Meanwhile, we should begin to consider letting the rest of the population resume some activity. We can do this safely if we remember that the Achilles’ heel of this virus is its targeting of a specific profile of people who are vulnerable in our country – people we as a society can protect – and use our innovation to serve.
Given the low risk of severe or critical Covid-19 infections in those people without comorbidities, it would seem that this group could be allowed to return to work in a phased manner adjusted for risk and age – of course, with sustained focus on rigorous hygiene, wearing face masks and continuous assessment of the effects of de-quarantining.
This method could beat the results of “flattening the curve” because we are now specifically shielding the at-risk groups while healing the economy before that becomes a comorbidity for all of us.
Given the prevalence of the comorbidities in the US population, this would be a contentious message. It would, however, mean that a significant section of the workforce could go back to work relatively soon and we would have a chance at patching the hole in the economy before the damage is irreparable.
It is imperative that at the very least, we should start this conversation now.