[COVID-19.P3] The Point of No turning back

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Recently, I wrote about the hope for treatment and prevention of COVID-19 and the parallel complacency of the US in its management the outbreak (find the article here). As the infection escapes the border of China, we have seen both the surge and spread of cases across the world.

Now it is the time to ask, when would we completely lose this battle? When the number reaches 100 cases? 1000 cases? 1 million cases?

In short, we lose our control when the capacity of medical resources, including equipment, hospital beds, and workforce, of the entire national healthcare system outruns the demand of life-threatening cases. Imagine if you have difficulty breathing or you present with febrile convulsion, but all hospitals have run out of beds, ventilators, or caregivers, and you are left with the only option to go home. Other cases being hospitalized are as severe as yours, and unfortunately, you have arrived too late. When you walk out of the hospital, you see hundreds, or thousands of those like you, waiting for a bed, a ventilator. Inside, doctors and nurses have worked thousands of hours on end, and some of them have got infected with SARS-CoV-2 (the virus that causes the severe respiratory syndrome termed COVID-19). In the end, we lose medical staff to the virus while recording a continuous increase in the number of hospitalizations.

Without aid, this is the point of no turning back.

It is important to know how we lose, so we could know how we could prevent it from happening. Certainly, the number of infections does not reflect the proportion of severe or critical cases. Reality is, many young people have got, or would be likely to be, infected with the virus while some of them would require as much intensive medical treatment as an elderly person would. We have to be alert that the sheer presence of young age does not guarantee natural recovery. The Chinese doctor and whistleblower, Li Wenliang, was treated with combination of antibiotics and antiviral drugs and assisted with breathing through artificial lungs. Yet, he passed away at the age of 34. So, when we marvel at the high percentage of recovery, we have to be cognizant that these cases did not recover just on their own chance. This young population has also received extensive and timely medical intervention. The healthcare system, at presence, is the bloodline to fuel our battle against the outbreak. Age supremacism is not.

How not to lose?

In early January, when China arrived with an action plan, it was 3 weeks late. China would have lost control of this outbreak without timely construction of field hospitals, enforcement of large-scale containment, and civilian cooperation in community isolation. The speed, efficiency and resilience of China has finally paid off despite a tremendous loss in human and economic resources. On March 11, the country recorded only 24 new cases, with 84% recovery among all infected cases. Those 80,000 cases of China constitute a case study with a very large sample size, and the conclusion of the study has never been clearer: Containment is the only way to stop the pandemic.

If it is not clear to you, let’s look at South Korea. Back in mid-late February, COVID-19 seemed to accelerate its spread, but Korea has aggressively stopped the outbreak by its delivery of testing to its population (at its peak, 10,000 cases/day) in combination with effective containment. Within a matter of weeks, reports of new cases “flatten,” and the number of active cases is on their way to drop.

What China and Korea has accomplished is actually "flattening the curve."

Flattening the curve, or the process of systemic stabilization of new cases over time, aims to protect the medical system from a point of no turning back, like what Italy is experiencing, but also buys us time to manufacture medical supplies, develop vaccine/therapies, and for hospitalized patients to recover and reserve those hospital beds for upcoming cases.

In order to flatten the curve, the large population needs to gain access to testing such that we can quarantine and isolate positive cases, including asymptomatic individuals, while concurrently allowing the negative cases to resume their normal life. Currently, the US still restricts testing criteria to symptomatic patients, concurrently negative for the flu, or the elderly, those with underlying conditions, or those having exposed to confirmed positive individuals or returned from outbreak centers.

The US did not realize that when China and Italy offered testing en masse, the number of cases jumped exponentially. In China, there were 444 cases on January 23, just one week later the number jumped to 4903, and, one more week, 22,112. In Italy, similarly, in 3 weeks these numbers were 62, 888, and 4636 respectively.

Thus, if the criteria for Americans to access test remain as strict as they are now, 1,300 US cases are clearly just the tip of the iceberg. In particular, I would like to mention the following three recent studies:

(1) In this study in the New England Journal of Medicine, an index patient infected with Covid-19 still presented a high viral load even at end of symptoms. The article was published on March 5th on NEJM. Even though the group did not prove the viability of the virus (through in vitro culture of viral particles), but the high viral load directly suggests an active replication, and that the virus is capable of infecting others.

(2) In the case of lower viral load, another study by a group of German researchers has made similar suggestion: SARS-CoV-2 virus has a prolonged shedding pattern that exceeds the end of symptoms. They also recommend that the persistence of low viral load (<100,000 copies / ml) at 10 days after onset of symptoms are both required for assessing the risk of transmission in discharged patients.

Thus, to affirm complete recovery, the patient must get tested for his persistently low or negative viral load, and not by mere symptoms alone. Unsurprisingly, if the virus has a prolonged shredding pattern, you would expect reports of discharged patients tested positive for the virus despite their complete recovery of symptoms.

Herd Immunity

I would like to address the theory in the media about herd immunity through spreading. Essentially, they hypothesize that the United States or Europe (in reality, only the UK) has intended to allow the spread of outbreak in order to create herd immunity: a “one sick, two happy” theory. I believe that when we form a hypothesis, the first thing we need to do is to argue against our own hypothesis.

Herd immunity is accomplished through delivery of vaccination to the majority of population, through which we create a “majority immunity,” meaning (1) to protect the vaccinated ones from getting infected and (2) to protect the unvaccinated from getting infected (because the risk of transmission is significantly lowered). What happens if we do not, or have not yet to, acquire herd immunity?

According to a recent epidemiology study by Imperial College, if the absence of any intervention or behavioral change, 81% of British population would get infected, and 512,000 people are expected to die. Similarly, if the US decides to take no action, within 3 months, 2.2 million people would die from COVID-19. SARS-CoV-2 is a novel virus in which human as a species has never encountered before. Rarely, some of us would have a natural immune system against this virus. In the majority of cases, we would subdue to a viral infection which would mount a range of symptoms from mild to severe in individuals.

Herd immunity is a reflection of public health containment and is not synonymous to the concept of medical priority. On the battlefield, if two soldiers A and B are both struck down, the option to save A or B would simply depend on whoever with a better prognosis. Given scarce medical supplies, if we choose to save B and cannot save B, then the time A waits for his turn can make A as critical and severe as B, and in the end, we would lose both A and B.

This choice is clearly in no one’s favor, but to win this battle, we have to save lives. Therefore, at this time some countries are "prioritizing" resources for save-able cases, and they "surrender" on cases that would have low chance of recovery despite the same medical support. However, in parallel with medical prioritization, we must be very aggressive in containment. Herd immunity can happen only after we have effectively contained the spread of the pandemic, not “ahead of the curve” as the theory has proposed.

When do we lose?

By limiting access of the public to COVID-19 tests (because of shortage of testing kits or of strict criteria), the US might not realize that they are sacrificing a critical window of success. We lose when hospitals simultaneously record an exponential increase in the number of severe and critical cases, with a higher death rate in the US compared to global average, as in Italy at ~8.3% now. Only then would the US realize they have made a big mistake not containing the outbreak timely and effectively.

On Wednesday, China has agreed to send experts, medical supplies and equipment to assist Italy. Given the sense of American exceptionalism and Trump’s uncanny ability to burn diplomatic bridges, who would come to America's aid?

The US healthcare system is placed #1 in the world only in terms of navigational complexity and cost. Yet, the number of hospital beds per 1,000 people in the US is 2.4, lower than Italy (3.2), China (4.3) or Korea (12.3), countries that are still struggling to control the epidemic. Currently the US has about 46,500-95,837 ICU beds and ~ 160,000 ventilators according to American Hospital Association and Johns Hopkins report (embed link). If COVID-19 pandemic spreads only moderately, the healthcare system would need at minimum 1 million beds and 200,000 ventilators.

Without aggressive containment now, America will surely lose against the pandemic.

Conclusion

Community isolation is the very least a country must do to prevent the spread of epidemics, reduce deaths and protect its own healthcare system. In this battle, if you cannot fight and win quickly, you must try to survive the longest. In order to survive, you must give every one the opportunity to test for the novel virus regardless of their need for medical intervention.

Every health crisis tests the strength and resilience of a healthcare system. Hopefully the US will weather this storm, and the president of 2020 would never give public health advice based on his hunches. Never again.