The Emergence of Severe Acute Respiratory Syndrome (SARS)

“The message we are getting is if we don’t take care of nature, it will take care of us.” — Elizabeth Maruma Mrema, Acting UN Executive Secretary on the Convention on Biological Diversity.

“It boggles my mind how, when we have so many diseases that emanate out of that unusual human-animal interface, that we don’t just shut it down. I don’t know what else has to happen to get us to appreciate that.” — Dr. Anthony Fauci on live animal markets, aka wet markets, in Asia and elsewhere. 

“The term wet market is often used to signify a live animal market that slaughters animals upon customer purchase.” — X. F. Xan

“This is a serious animal welfare problem, by any measure. But it is also an extremely serious public health concern.” — Kitty Block, President and CEO of the Humane Society of the United States.

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As we come closer to the present time, to the present COVID-19 Climate of Pandemic, we run into illnesses that are more mysterious. HIV, for example, has been the object of intense investigation and scrutiny for many decades now. So the level of knowledge about how HIV emerged is quite rich. Less so with Ebola, but that infection is still moderately well understood.

SARS — Another Novel Illness

With the newer SARS illness — short for severe acute respiratory syndrome, the well of scientific understanding from which we can draw is far more shallow. But it is certainly relevant. For the present global pandemic which now has paralyzed our entire civilization and which threatens to take so many of our lives resulted from the second strain of human SARS to emerge in our world.

What we do know is that the SARS virus is another new zoonotic illness. The first strain of SARS broke out in a 2002 epidemic in China that then rapidly spread. It emerged from a family of coronaviruses. A set of viruses that typically cause mild respiratory infections in humans. But SARS virus is not mild. It is quite often severe — resulting in hospitalization in a high proportion of cases. It also shows a much higher lethality rate than typical illness.

SARS comes from a lineage, like HIV and Ebola, that had previously thrived in the hotter regions of the globe. It was harbored in tropical and subtropical animal reservoirs. It emerged at a time when animal sicknesses were likely amplified by direct environmental stresses caused by forest clear cutting, human encroachment, and the broader sting inflicted by the climate crisis. The novel awakening of SARS was, finally, yet another case where harmful contact with sick animals resulted in a transfer of a new illness to human beings. 

Coronaviruses in Hot-Bodied Bats in a Hot Weather Region

The first strain of human SARS illness was genetically traced back to a coronavirus ancestor in horseshoe bats — a tropical and subtropical bat species — in 2002 by Chinese researchers. Like the Ebola Virus and HIV before it, SARS-like illness circulated through various species in tropical and sub-tropical environments in a traditional reservoir long before transferring to human beings.

 

Horseshoe bat primary range

The primary range of horseshoe bats is paleo-tropical. Horseshoe bats, according to genetic research, are an animal reservoir of SARS virus. Image source: Paleo-tropical environment.

Studies note that bats are a reservoir for a great diversity of coronaviruses. The bat anatomy is a warm one in a hot weather environment — subject to constant exercise and exertion in regions where it’s not easy to cool off. Elevated body temperature is a traditional mechanism for fighting infection. So these viruses have to constantly adapt and mutate to keep hold in the bat population.

At some point, one particular strain of coronavirus jumped out of the bat population and into another animal species. A paper in the Journal of Virology suggests that the genetic split from bat cornaviruses and SARS occurred some time around 1986 or 17 years before the 2002-2003 outbreak. At that time, it is thought that this hot weather illness from hot-bodied bats had moved to another, intermediary, animal host.

SARS in the Little Tree Cats — Palm Civets

The first emergence of SARS is thought to have occurred when palm civets — a kind of Southeast Asian tree cat — consumed coronavirus inflected horseshoe bats. The civets typically dine on tree fruits. But as omnivorous creatures they also eat small mammals. In this case, civets are thought to have eaten sick bats and become sick themselves.

Himalay_Palm_Civet
The Palm Civet of Southeast Asia — hunted as bush meat for the Asian wet markets. A practice suspected for transferring SARS from bats to humans. Image source: Black Pearl, Commons.

Palm civets live throughout much Southeast Asia. Inhabiting a swath from India eastward through Thailand and Vietnam, running over to the Philippines and southward into Indonesia. A tree-dwelling creature, they prefer primary forest jungle habitats. But they are also found in secondary forests, selectively logged forests, and even parks and suburban gardens. All of which overlap the environment of horseshoe bats and their related coronavirus reservoir.

The leap from bats to civets and its development into SARS probably didn’t occur suddenly. Many civets probably consumed many sick bats over a long period of time before the coronavirus changed enough to establish itself. But at some point in the 1980s, this probably occurred.

From that point it took about 17 years for the virus to make its first leap into humans. How the virus likely made this move is eerily familiar — taking a similar route to the devastating HIV and Ebola illnesses.

Wet Markets — Butcheries For Asian Bush Meat

A major suspect for the source of this particularly harmful contact is the Chinese wet market system. A wet market is little more than a trading area that contains, among other things, live and often exotic animals for sale as food. A person entering a wet market is confronted with thousands confined live animals. They can point to a particular animal and a wet market worker will butcher the creature on the spot.

It’s literally a very bloody business. The butchering occurs in open air. Blood and body fluids can and often do splatter anywhere. As a result, the floors are typically wet from continuous drippage and, usually partial, cleaning — which is how the market derives its name.

Palm civets can often be found in wet markets as food in China. Trappers for the wet markets range the Southeast Asian jungles bringing in civets by the thousands. The civets were reservoirs for SARS virus. They were slaughtered in the messy markets. People were exposed. In 2002 and in 2019 they got sick.

Though palm civets have been identified by many avenues of research as a likely source of SARS, raccoon-dogs — whose meat was sold in wet markets — were also shown to be SARS type virus carriers. These animals have a similar diet to that of civets, share their habitat and were similarly vulnerable to infection from the bats. In addition, pangolins — a kind of scaly anteater — have been identified as a possible carrier of the SARS-CoV-2 virus. And pangolin meat is also sold for consumption in Vietnam and China.

Given our knowledge of how zoonotic illnesses move in animal populations, it’s possible that multiple species are involved in the ecology of SARS and related coronaviruses. In essence, there is a strange and ominous similarity between wet markets in Asia and the bush meat trade in Africa. They are both means of moving jungle meats from animals (who may be reservoirs for novel illnesses) in tropical regions into the human population. Often in a fashion in which the treatment and preparation of the meats to be consumed is haphazard and unregulated.

First SARS Outbreak — 2002-2003

Ultimately, the disease percolating through likely stressed natural systems found its way into the human population in late 2002. The epicenter was Guangdong Province in China where the highest proportion of early SARS cases by a significant margin (39 percent) showed up in people in the live animal food trade. In other words, people who butchered animals or worked closely with those who butchered animals.

The initial infections, which were traced back to November in China, resulted in spikes of pneumonia incidents in local hospitals. The cause — a then unknown illness that was later called SARS. SARS was another terrifying illnesses. Its symptoms could emerge rapidly or slowly over a couple of days or weeks. It could mimic flu-like symptoms before suddenly surging into a terribly lethal illness that attacked the lungs — rendering victims unable to breathe under their own power. At first, case fatality rates (the percentage of people who died as a result of SARS) ranged from 0-50 percent. The ultimate recorded fatality rate from the initial outbreak in 2002 would settle at 9.6 percent or about 100 times more lethal than seasonal flu.

SARS cases 2002 2003 outbreak

Cumulative reported SARS-CoV cases during the 2002-2003 outbreak. Note that early case reporting was incomplete. Image source: Phoenix7777 and WHO.

From the point of early infections, patients then passed on the virus to healthcare workers and others. Though SARS was not as crazy lethal as HIV and Ebola on an individual basis, it was quite infectious. Meaning it was much easier to pass on to others than either of those earlier emerging zoonotic illnesses. This higher transmission rate resulted in a greater risk that more people would fall ill from SARS over a shorter period of time — exponentially multiplying the virus’s lethal potential.

Transmission to workers in hospitals and care facilities was notable as typical sanitation procedures were not enough to limit virus spread. In hospital settings, the transmission rate for this first SARS illness (the number of people each infected person then got sick) was between 2.2 and 3.7. Outside of sanitized settings, the transmission rate ranged from 2.4 to 31.3. A particularly highly infectious patient, called a super-spreader, resulted in a mass spread of illness to workers at Sun Yat-sen Memorial Hospital in Guangzhou during January of 2003 and subsequently to other parts of China’s hospital system. Masks and protective gowns (PPE) were ultimately shown as necessary to contain SARS infection in hospitals.

China’s early failures to report on the 2002 SARS outbreak resulted in a somewhat delayed international response. But by early 2003, the World Health Organization was issuing warnings, advisories and guidance. Disease prevention agencies within countries issued their own responses including diligent contact tracing and isolation protocols. The containment response both within and outside of China was thus in full swing by early 2003. This action likely prevented a much broader pandemic. That said, a total of 8,096 cases were reported — 5,327 inside China and 2,769 in other countries. With the vast majority of cases occurring in China, Hong Kong, Taiwan, Canada, Singapore and Vietnam. In total, out of the 8,096 people reported infected during this first SARS outbreak, 774 or 9.6 percent, perished.

SARS-CoV-2 Tsunami on the Way

Unfortunately, infectious diseases show no mercy to fatigued and degraded infectious disease responses. They lurk. They mutate. In their own way, they probe our defenses. They are capable of breaking out to greater ranges when diligence, ability, or will to protect human life wanes among leaders. And a smattering of SARS cases reported during the 2000s following the 2002-2003 outbreak continued as a reminder of its potential. So as with HIV and Ebola, we face waves of illness with SARS. With the next outbreak resulting in a global pandemic that will likely infect millions and kill tens to hundreds of thousands during 2019-2020.

Up Next: COVID-19 First Outbreak — Viral Glass-Like Nodules in Lungs

 

Harmful Contacts with our Living Earth and Redounding Shots Across the Bow

About two-thirds of all infectious diseases in humans have their origins in animals. Scientists say the ability of a virus to mutate and adapt from animals to the human system is very rare, but the expansion of the human footprint is making that rare event much more likely. — Jeff Berardelli

Contact — the state or condition of physical touching.

Harmful or unwanted contact — an assault.

Redound (archaic) — to come back upon; rebound on.

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How do you get sick from a virus? In the most simple sense, the virus touches your skin, your eye, the inside of your mouth, your blood or some other part of your body. It makes contact. Then it gets inside to do its damage. Often, this is through some action that you take. Some voluntary, some involuntary. Breathing, moving, picking up objects, putting contaminated clothes or blankets on or venturing into environments where other carriers of the virus can touch you. Or even, in a broader sense, disturbing the virus carriers and changing their environment is such a way that makes it easier for them to literally come to your home community to roost.

Contact.

In the last chapter we briefly explored how the world houses many, many potential, new, and re-emerging illnesses. Kept away from humans in mostly safe or remote places. We also briefly looked at how those illnesses are expanding. In this chapter, we will take a deeper dive into the second part. To look at how some harmful elements and activities within of our civilization have wrecked some of those safe places, how they’ve gotten us into what amounts to a brutal embrace with the places and beings in living nature that are reservoirs to those illnesses. How in this epic and global struggle, often bad actions and behaviors have shaken some illnesses loose. How it’s all gotten many of us sick.

That’s our present and recent history. One of harmful contact. Of touching and grasping for things best left undisturbed. And how it’s getting worse. How the general disturbance is rippling outward and bounding back.

We’re living in a time of an explosion of new illness or the re-emergence of old illnesses previously thought contained onto the global scene. How this has happened first became a major part of the discussion among health and epidemic experts since around the 1980s. For at the time, we experienced one of our initial major warnings that diseases may be dedounding onto expanding global civilization. And this first warning came from a terrifying new illness. For HIV humbled a global health corps that until that point had seen a long string of victories arising from the advances in medical science during the 19th and 20th Centuries.

HIV — Major Warning Shot to the Global Health System

HIV heralded an ominous new era. One where victory against infectious illness was less certain or at least came much slower and at a much higher price than earlier medical science victories might have given us hope for. One in which disrupted, damaged, or harmfully contacted life (and its supports) appears to return a toll on humankind as various enormous and harmful activities spread — burning, deforesting, killing and eating, and polluting their way across the globe.

virus3d rendering of a virus

3D rendering of HIV. Image source: National Foundation for Infectious Diseases.

Since its first outbreak as a pandemic during the early 1980s, HIV has infected over 75 million people of which around 32 million have died as a result of an illness that jumped to human beings from primates. Many deaths occurred early in the pandemic outbreak as first treatments were mostly ineffective. But even today HIV kills between 500,000 and 1,100,000 people each year (770,000 during 2018).

HIV originated in the broader African rainforests. There its progenitor reservoir existed as semian immuno deficiency virus (SIV) in the great apes and monkeys of the jungle for more than 10,000 years. All without transferring to humans until very recently. Our best present understanding is that the ultimate zoonosis occurred due to the bush meat trade in Africa which produced multiple contacts between SIV in apes and the blood of humans.

Hunting, Rubber and Bush Meat

The story of the bush meat trade is one that should be eerily familiar to those researching the climate crisis. Because it is also a story of forced displacement of human populations which then results in a harmful interaction with the natural world and subsequent damaging upshots. In the period from around the 1880s to the 1920s, sub-saharan Africans were forced from their native rural homes in droves as waves of Europeans descended on the jungles of Africa.

The Europeans wanted elephant tusks from the hunting trade to be sent home to Europe. They wanted rubber vine sap for industrial uses. They wanted to commoditize the jungle for these and other products. But often the Europeans didn’t have the manpower or local knowledge to conduct effective hunting expeditions into the jungle without the help of native populations. And they needed a local labor force for the rubber vine trade. Tribal Africans were pressed into service for the expeditions and the industrial exploitation of jungle plant products, often at the point of a gun.

This was a kind of mass invasion of the jungle in which abused and often under-nourished natives needed a new food source to survive. Rural subsistence agriculture wasn’t a possibility for a constantly mobile porter in an elephant hunting expedition. Nor was it for rubber plant harvesters or those newly impressed into factory work in burgeoning cities.

Bushmeat

“At this bushmeat market in Pointe Noire, a butchered chimpanzee is shown in the middle of the photograph, along with other smoked and fresh meat. It has been theorized that SIV moved from chimpanzees and sooty mangabeys to humans—evolving into pathogenic HIV-1 and HIV-2 respectively–through exposure to primate blood, most likely as a result of the bushmeat trade. The HIV-1 group M epidemic likely began in the region of Kinshasa, Democratic Republic of Congo. Although wild chimpanzees are not found in the immediate vicinity of Kinshasa, the city is situated on the Congo River, which allowed for the easy transport of SIV-infected bushmeat and of infected humans from rural to urban areas.” Image and caption source: Physicians Research Network and the Goldray Consulting Group.

So a kind of shadow trade in bush meat arose. Porters on hunting expeditions would opportunistically kill and butcher the jungle animals they came into contact with to supplement their diets. It was an ironic and ominous outgrowth of the abuse handed down to the native Africans by the Europeans. It was almost as if they’d been corrupted by the hunting and killing they were forced to take part in such that it became a new means of survival for them.

The Monster that Lives in the Jungle and the Monster that Lives in Us

Various strains of SIV lived in the blood of apes and monkeys in Cameroon and Sierra Leone. Porters and laborers driven into the jungle killed and ate their hominid relatives to survive the European expansion into Africa and its subsequent exploitation. Hunted chimps and monkeys fought back. They bit. They flung feces. Tired porters and laborers hunting chimps after endless hours of work made mistakes. They missed when cutting chimp meat off of bones. They under-cooked bloody meat. They cut themselves with bloody knives containing the blood of their hominid fellows. The SIV living in the blood of the monkeys and apes its way into the blood of the porters and laborers. It happened many, many times.

At first, SIV was a mild virus in humans. It didn’t live well in the new host. But viruses are weird. Like life, they mutate. They change. They adapt to new environments. If there is one prime directive a virus has in its intrinsic design it is to self-replicate. At some point in all the butchering and eating and messy cutting or in the conflicts between the people hunting the apes and monkeys for food and the fighting creatures struggling for very existence, there was an SIV transmission into humans that caught fire. Changing from the mild SIV to the raging and lethal human immuno-deficiency virus that we know today.

It had to have happened multiple times. We know this, in part, because there are not one but two progenitor strains of HIV — HIV 1 which links back to apes and chimps in the Cameroon region and HIV 2 which links back to Sooty Mangabays in the Sierra Leone and Ivory Coast region. A grim bit of evidence pointing to how widespread the harmful contact was that resulted in the virus’s leap into humans. The point in time at which the consistent leap was made is thought to have occurred in the pre-World War 2 period — possibly as early as 1908.

Once the leap happened, the machine of exploitation in Africa that the colonialists had set up then served to help spin the virus out into the broader human population. Industrial centers and related communities had sprung up around the animal products and jungle harvesting trades. And in those centers prostitution of various kinds was rampant. Already established human illness such as syphilis, chlamydia and gonorrhea became widespread in Africa. These illnesses assisted the spread of HIV into hundreds of people by the mid 20th Century. This created a consistent viral HIV reservoir in humans from which the major pandemic later emerged.

Ebola — Novel Jungle Hemorrhagic Fever

If HIV was the first known serious illness to arise through harmful human interactions with ancient tropical and subtropical disease reservoirs, it became sadly apparent early on that it would not be the last. More human beings were coming into contact with the old animal disease reservoirs moving from previously sequestered habitats than before.

Ebola cdc

An electron microscope image of Ebola virus. Image source: CDC.

Cities were extending into the jungles, animals carrying illnesses foreign to humans were moving into those cities. Deforestation and slash and burn agriculture was displacing them, driving them. And in most new places that the animals moved there were human beings as well. A new harmful interaction, the climate crisis driven by fossil fuel burning, was also beginning to heat up the world. This served as a new pathway for expansion — increasing the habitable range for creatures used to hot weather and typically averse to cooler climes. This greatly increased and continues to increase the spatial range of tropical and semi-tropical illnesses capable of infecting people.

Of the jungle fevers that arise from the hot regions of the world, that are carried by animals that live in this heat, the viral hemorrhaigc fevers are perhaps some of the most terrifying. Like HIV, they are seriously lethal — tricking the body’s immune response in a way that enables them to multiply out of control. Directly attacking the body’s linings, they thus cause such great cell death that they effectively blow holes in tissue. This breaks down the body’s integrity causing loss of fluid and ultimately bloody hemorrhage.

From Viral Brush-fire to Conflagration

The first instances of Ebola occurred in 1976— in Sudan and then in Zaire. These initial infection outbreaks were highly lethal and terrifying to the local populations effected. Of the 284 people suffering from the Sudan strain of the virus, 151 died. In Zaire, 280 out of the 318 infected souls (88 percent) perished. For a relatively short-lasting infection, Ebola was amazingly lethal. Though later, less deadly strains emerged, many of the outbreaks to follow would continue to kill a surprising number of those afflicted. Presently, the World Health Organization estimates the lethality rate for Ebola, overall, at 50 percent. Sudan and Zaire both hosted different strains (SUDV and EBOV) of the same virus — Ebola — which was named after the river region from which it emerged.

It is still not fully known how the deadly Ebola virus first made its leap into humans from animals. But it is well known that tropical fruit bats, porcupines, and primates — yes our poor hominid relatives again — can carry the virus. As with HIV, the harmful bush meat trade is one of the key suspects. Although with Ebola, there are many other possible modes of zoonosis from animals to humans.

The virus is more transmissible than HIV, though less so than many other illnesses, such that direct contact with blood, secretions, organs or other bodily fluids of infected people or animals, and with surfaces and materials (like bedding and clothing) contaminated with these fluids can result in sickness. It is thought that eating fruits partially eaten by fruit bats, food contaminated by bat or other infected animal feces, or consuming bush meat are all means of animal to human transfer of the illness.

Ebola Jungle Ecology CDC

Initially, the bush meat trade was a prime suspect for transmission of Ebola to human beings. Presently, it’s understood that other contacts with infected animals or their bodily fluids may transmit the virus. Also, at first, Ebola primarily impacted areas bordering the jungle. But in recent outbreaks, major population centers have been impacted. Image source: Ebola Virus Ecology — CDC.

Notably corpses of both humans and animals who were killed by the illness remain infectious for some time — requiring special burial. The disease typically spreads from human to human through direct contact with the blood, semen, saliva, vomit or other body fluid of infected persons. Surfaces contaminated by these fluids are also a means of infection. The virus is thankfully fragile in air, but splashing with droplets can transfer illness. And the virus is known to live in droplets on surfaces for up to 3 days.

After Ebola first burst onto the scene in 1976, there was a long hiatus of epidemic outbreaks in humans. Some thought, hopefully, that the disease had faded back into its tropical environs. But in 1995, nearly two decades after its first emergence, the virus broke out among humans in Zaire again — this time infecting 315 and killing 254. Subsequent outbreaks occurred every five years or so leaping to Uganda in 2000 (425 cases, 224 deaths), the DRC in 2003 (143 cases, 128 deaths), again in DRC in 2007 of a less lethal strain (149 cases, 37 deaths) and in 2012 in both Uganda and DRC yet again in three separate outbreaks (Uganda — 31 cases, 21 deaths; DRC — 57 cases, 29 deaths).

Thus far, outbreaks of the novel illness had been relatively small if intense viral brushfires. And, though lethal, the virus was thought be inhibited in transmission. A major outbreak spanning from 2013 through 2016 would belie that impression. Looking back, the illness had mostly been confined to small settlements bordering jungle regions in the 1976 to 2012 timeframe. But in 2013 and 2014 the virus, possibly through the enlarging span of its animal reservoirs, penetrated into more densely populated urban and city environments. From these more packed regions the virus would explode to rage out of control for years — consuming many thousands of human lives.

The West African outbreak which would hitherto dwarf all previous episodes of Ebola began in late 2013. Then, a one year old child perished from Ebola infection from an unknown source. Afterward, the disease rapidly spread through her community in Guinea, out into the local region and then on through the nearby countries of Liberia and Sierra Leone. What precipitated was a global health emergency that reached catastrophic proportions by summer of 2014 with the virus overwhelming the medical capacity of impacted countries. At this point the illness threatened to go global — with a handful of cases leaping to neighboring countries in Africa and even transferring overseas. But intense contact tracing and strict isolation both inside and outside the virus hot zone was largely responsible for preventing further spread.

By the end of the outbreak in 2016, an estimated 28,646 infections had occurred of which 11,323 were reported to have died. Ebola had risen from the ranks of a fringe if rather scary illness cropping up on the outer edges of society to an illness striking directly at the bones of global civilization. It had shown its ominous potential.

Subsequent outbreaks in 2017 and 2018 in DRC and Equateur Province mirrored previous less widespread infections. But a new outbreak that began in 2018 in the Kivu region of DRC and extends to today is considered a global health emergency by WHO. This particular outbreak as of 29 March, 2020 is reported to have infected 3453 people of which 2273 have died.

Warning Shots Across the Bow

Both Ebola and HIV served as early warning shots across the bow of global civilization. Visible signals that the risk of catastrophic emergence of new infectious illness was on the rise. That our harmful contacts with the natural world were the primary source of this rising risk. And that many, many more human souls may be at stake. These two novel illnesses were not the only major emergences to occur in this time. In fact, a plethora of new and re-emergent sicknesses have come onto the global scene over the past four decades. But they both represented the ominous character of the larger risk human beings now faced. They also foreshadowed the follow-on emergence of SARS into a major global pandemic — which we’ll be talking about in the next chapter.N

(Up Next — The Emergence of Severe Acute Respiratory Syndrome)

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