The new coronavirus is an environmental issue arising from human disruption of our planet's wildlife. We thoughtlessly proliferate our numbers; blast highways through jungles; eat wild animals; clear forests for suburbs, farms and industries; and are surprised when nature bites us back. Pulitzer-winning science writer Laurie Garrett's 1995 book The Coming Plague warned us, but it took the 2002-2003 SARS (severe acute respiratory syndrome) epidemic for us to take "zoonoses"--infectious diseases arising from contact with wild animals--seriously.
Viruses are biological structures standing somewhere between non-life and life. Unlike living cells, they reproduce only inside the cells of living hosts. Upon infecting a cell, a virus forces the cell to produce thousands of identical copies of the virus. Being made of DNA, viruses quickly evolve and adapt to changing circumstances.
The new disease, dubbed covid-19, arose in cave-dwelling horseshoe bats in China. Bats come in sundry varieties, comprising 25 percent of all mammalian species. They make convenient viral hosts because their immune systems, evolved to tolerate the unique stresses on the only mammal that flies, allow them to endure viruses. All mammals easily share their diseases with humans because of their genetic similarity to us. It's not surprising that another zoonosis, Ebola, originated in Africa probably from bats that infected monkeys that humans consumed.
According to David Quammen, author of Spillover: Animal Infections and the Next Human Pandemic, "live markets" selling living wild animals for immediate butchering, are "very, very dangerous." Cages full of live bats, civets, chickens, porcupines and other creatures, stacked up with animals defecating on one another, are a viral mixing-bowl. Researchers trace the covid-19 outbreak to a live market in Wuhan, China, where evidence points toward civets (a cat-like mongoose) or pangolins (armadillo-like, the world's most illegally marketed mammal, valued for its presumed healing power) as the likely "amplifiers" for covid-19. The virus jumped from bats to either civets or pangolins in the market, adapted to its new host, multiplied, and was then consumed by humans.
Like flu and SARS, covid-19 is a respiratory illness characterized by fever, cough, and shortness of breath. Highly communicable, it is transmitted not only by droplets during sneezing or coughing but also, more dangerously, directly through the air like SARS, so you can catch it simply by breathing exhaled air.
Covid-19 probably kills 1 to 3 percent of its victims -- a dangerous number but less so than the 10 percent deaths-per-patient rate of SARS. For comparison, 45 million Americans contracted the flu during the 2017-2018 flu season, of whom 61,000 died for a deaths-per-patient rate of 0.1 percent. So covid-19 is 10 to 30 times more deadly than the flu and five times less deadly than SARS.
Will covid-19 go pandemic (global)? For perspective, the 1918 Spanish flu pandemic infected 500 million, one-third of the world's population, and killed 50 million. As of this writing, there are more than 60,000 confirmed cases and 1,367 deaths from covid-19. These remain largely confined to China, which to its great credit is going all out to contain and extinguish the disease, even though China foolishly ignored its early signs. If containment works, we'll see big reductions in new cases during February. But China has many international connections such as its belt-and-road infrastructure initiative. Africa, with 47 multi-million-population cities and underprepared medical infrastructure, is fertile ground. If the disease becomes pandemic, humanity might be stuck indefinitely with this new more virulent flu-like disease.
The United Nations' World Health Organization, U.S. Centers for Disease Control and similar organizations worldwide are working toward a cure and a vaccine. Unfortunately, according to Quammen, the Trump administration is trying to reduce the CDC, cutting billions from its annual budget and hamstringing its operating ability. Public investment and education are essential. A possible cure, remdesivar, is being tested. Covid-19's genetic sequence was obtained and published weeks ago. Projects to develop a vaccine that attacks this sequence are under way in China, Belgium and Germany, with clinical trials in three months and real-world tests this summer. Vaccine mass production will present a huge challenge.
If we cannot stamp out covid-19, the planet will inherit another endemic, highly communicable flu-like disease that is perhaps 10 to 30 times more deadly (per patient) than flu.
Note well: Other outbreaks will occur and could be far more deadly. We must be better prepared than China was for covid-19. Live markets must be banned or tightly controlled and governments must take early warning signs seriously. Our best long-term defense is to support health education, health research and health infrastructure.
Commentary on 02/18/2020
Print Headline: Understanding the new coronavirus