Of bats, pangolins and Covid-19

So how did it start, this "Chinese virus" our President keeps referring to? 

I hope this brief scientific review can put this pandemic into a proper perspective.

Viruses are infectious agents that cannot survive or multiply on their own. So they hijack the DNA or RNA, protein-making mechanisms of other living organisms to thrive. But they first have to attach to, then pry open the host cell membrane. This mutual affinity is very precise and specific between a virus (famously diagramed with its "spikes") and the host cell surface "binding receptor" (think of this as a "key-and-lock" match).  This determines why some species are susceptible to a specific infection while others not at all. Another characteristic of viruses is their ability to mutate, meaning changing its genetic makeup and therefore (1) acquiring ability to infect new hosts; and (2), altering the severity of the infection or resistance to treatment.

Coronaviruses have been recognized since the 1960's as common causes of respiratory and gastrointestinal infections in humans and some other animals. Genetic studies have traced coronaviruses co-existing with bats for millennia as a primary host, but recently "jumped" to pangolins as new hosts, and now to humans. What makes this human SARS-CoV2 (otherwise called Covid-19) much more dangerous to humans is its selective mutation to (1) bind to human receptor ACE2, which is abundant in our respiratory tract; and (2) to activate furin, a host-cell enzyme found in many human tissues (lungs, liver and small intestines), allowing the virus to increase its infectivity and attack multiple organs. Call this natural selection: Pure luck for the virus, bad karma for us?

So now, what about the "Chinese connection"? The first reports of novel pneumonia came from Wuhan, China. Why China first? One can only speculate that the Asian traditional obsession of consuming exotic animal tissues as medicinal remedies has invited importation of pathogens along with illegally trafficked animals. While not conclusive, most revealing is that both Chinese and Western scientists have found pangolins imported into Guangdong province contain coronaviruses with receptor binding properties identical to SARS-CoV2, potentially identifying pangolins as intermediate hosts to human disease.

It was even a more heart-breaking revelation for me as I watched the PBS Nature show on pangolins (https://www.pbs.org/wnet/nature/worlds-wanted-animal-full-episode/16258/) documenting the effort of a few compassionate individuals who had tried, with little success, to stop the killing and trafficking of these adorable endangered creatures. Had the world listened to them, would this pandemic have ever occured? Who knows, as so many "exotic" wild animals, including ferrets, are sold in open markets and pet stores around the world. Viruses don't recognize human skin colors nor nationalities, they only exploit human weaknesses or follies, wherever we are.

Zoonotic diseases are a group of infections that humans acquire from animal reservoirs. There are too many of them to list here. From malaria already present in antiquity to Lyme disease and "swine flu" of modern times, West Nile encephalitis and Dengue fever expanding with the expanding range of their mosquito carriers, these are but a few examples. We need to remind ourselves that we live in a world where animal and human microbial cesspools are interconnected, ever-evolving, as humans encroach on wildlife habitats and contribute to climate changes.

This Covid-19 pandemic is likely the mother of all zoonoses we have ever seen, now described as catastrophic, or even apocalyptic. There are already, and will be many, many more stories written about it: more scientific studies; stories of human tragedies, courage and immense sacrifices; of economic collapse; of innovative changes in the workplace, social connectivity, responsibility and community health; and of course, angry finger pointing. Let's not forget the more existentialist lesson of how the wants, greed and follies of our human species can become our own peril, as we use our dominance on the world food chain to inflict cruelty over "lower" living species with whom we share, yes share, this beautiful blue planet.

Chinh Le

(A shorter version of this essay was submitted to the Gazette Times, March 26, and published on April 2, 2020)

What Covid-19 tells us about our healthcare system.

Ms Bailey used Italy's Covid crisis as a reason to say "I don't want the government taking over our healthcare system"(April 26). May I point out that the countries that have best responded to the pandemic are Taiwan, South Korea, Ireland and Singapore, which all have government-run healthcare. Such a system allows nations to better focus on public health, universal access to preventive and medical treatment, and to allocate resources when and where needed for the common good. There are many reasons for the tragic human losses in this pandemic, but please don't blame the Italians for incompetence.

Here in the US, where we have the best concentration of scientists, innovative technology companies and the highest healthcare expenditures in the world, we failed miserably to prepare for, and still have a hard time reacting to the crisis. The reasons are obvious: a fragmented, uncoordinated system, built on social inequalities, driven mostly by profit motives; and a current leadership that puts Wall Street over public health. Yes, politics and wealth over health. American exceptionalism at its worse.

During this pandemic, not a single person in Europe or parts of Asia where there is "government-run" health system lost their insurance, and the same applies to Medicare beneficiaries in this country.  With millions of Americans suddenly un-employed, this should be a wake-up call that employer-based insurance is no healthcare security at all. There is no better time to rethink replacing private medical insurance with an equitable, universal publicly funded healthcare system.

(Submitted to the Gazette Times, April 29; published May 9, 2020)