From Ancient Reservoirs

“The insidious emergence of HIV/AIDS and the lack of due attention by policymakers illustrate how some outbreaks that start subtly can grow to global proportions if they are not aggressively addressed early on.” — Dr Anthony Fauci

The Infectious Diseases Society of America recognizes climate change as a global health emergency and calls for policies responding to the intrinsic links between warming temperatures and rising sea levels and epidemic and pandemic events as well as other infectious disease threats to public and individual health. — IDSA

The climate system of our world envelopes it.

It represents the state of our atmosphere, our oceans, and the frozen regions we rely on. It interacts with and influences all things living here on Earth.

The present changes we now experience due to a climate in crisis are far-reaching. Disruptive to the balance of life itself. Harmful or even demolishing to ecosystems. Driving species of all kinds into new environments after their old safe places have been changed, disrupted, or taken away.

This is a story that we have become sadly familiar with as the burning of fossil fuels keeps dumping heat-trapping carbon into our atmosphere — resulting in rising seas, melting ice, stronger storms, worsening droughts, expanding heat, and far larger and more dangerous wildfires.

Global examples of emerging infectious diseases NIH

Global examples of emerging and re-emerging infectious diseases. Even before COVID-19, they were growing more numerous. Back in the early 1990s, this map showed just one illness — HIV. To humans, quite a few are now rather new. Others are re-emerging. Many are influenced by the climate crisis in various ways. Image source: Three Decades of Responding to Disease Outbreaks — NIH.

But there is one aspect of our changing climate that is often nuanced and overlooked — how the climate crisis can influence the spread of disease itself. How a disrupted global climate can drive sickness up out of the ancient reservoirs that have harbored it throughout the ages. How it can help accelerate the spread of new illness, make us more susceptible to sickness, or cause the re-emergence of previously well-contained diseases. Given the present context of a global pandemic caused by an entirely new illness — COVID-19 — it’s crucial to take a look at generally how harmful interactions with the natural world, particularly through climate crisis, are increasing risks of new and re-emerging diseases.

Reservoirs as Illness Havens

For what we know of as illness is also a kind of life.

Bacteria are micro-organisms. Viruses are pseudo-life and life-altering. And parasites are living things that dwell within or upon other living things. Climate change can generate or worsen such illnesses by directly affecting their environments as well. Creating the conditions that facilitate the transfer of diseases from typical ranges — called reservoirs — to new hosts. Developing pathways for expanded or new (novel) infections.

An illness reservoir is any person, animal, plant, soil or substance in which an infectious agent normally lives and multiplies. A harbor for the bacteria, viruses, or parasites that cause disease.

Human beings are reservoirs for certain diseases. These could be living humans or the dead — long buried and held dormant in ancient frozen tundra for hundreds or even tens of thousands of years. It is possible that the devastating illness smallpox (Variola virus), which was recently considered eradicated, may still be harbored by frozen dead humans entombed in the permafrost. That permafrost is now thawing as the Arctic heats up.

Animals can also be reservoirs — rabies, for example, lives in bats, raccoons, skunks, and foxes. Cholera is a bacteria that lives in water. It can also live in humans and zooplankton. And there is a link between the spread of Cholera and the loss of water security — which the climate crisis risks. Anthrax lives in herd animals like sheep and reindeer. Because it is capable of developing spores, Anthrax can survive for decades in the bodies of dead reindeer and the climate crisis produced thaw of permafrost has already resulted in new outbreaks of this illness in herd animals and, in rarer possible cases, human beings. Dengue fever is a nasty virus harbored by both humans and mosquitoes. And it is worth noting for diseases which cause illness and loss of life in human beings that mosquitoes — whose range can be greatly altered by changes in climate — weigh quite heavily.

Zoonosis — The Transfer of Illness From Animals to Humans

During recent years, human beings have unfortunately seen the emergence of numerous new or novel illnesses. Many of these illnesses have arisen as the result of mistreatment of nature. Our disruption of the natural world and harmful or abusive relationships with animals appears to have done double duty in getting us ill. For a good share of the nastier new ailments have arisen as the result of zoonosis — or the transfer of diseases that previously affected only animals to human beings — involving such harmful acts.

The harmful bushmeat trade in Africa is thought to be the origin of the novel HIV virus transferring from its original reservoir in primates as SIV before mutating into a stronger illness in humans during the 20th Century to become common from the 1980s onward. Though there is little clear and present evidence that the jump from animals to humans for HIV was directly influenced by the climate crisis, the link between harmful industry and disease transfer is a bit close for comfort here. It is also worth noting that those living with HIV are among the most vulnerable to increasing extreme weather events and related disruption of human habitat and support systems driven by the climate crisis.

SARS illnesses (of which COVID-19 is a subset) and Ebola are also novel viruses in humans. As with HIV, they are likely zoonotic illnesses. This means they originated in animal host reservoirs but, through some process of contact, transferred to human beings. These viruses are still rather mysterious in that they presently have unconfirmed reservoirs. But both are reasonably suspected to be harbored by animals — with tropical and subtropical bats relatively high on the list.

With Ebola in particular (we’ll talk about some similarities between Ebola and SARS due to suspect reservoirs in the next chapter), there is a bit of an ominous interaction with the climate crisis. New modeling produced in Nature Communications suggests that under the present pathway of global heating, Ebola epidemics in Africa could occur once every 10 years — or almost twice as often as they do at present. This is because the bats and other animals that are thought to harbor the virus are expected to be driven by warming temperatures into new areas — expanding the epidemic-prone region by 20 percent.

Expanding Heat

The heating function of the climate crisis is very well understood. And, early-on, scientific research from world health and climate agencies identified the risk that more global heat posed to expanding illness. In particular, mosquitoes which are both reservoirs and vectors (agents of disease transfer) for numerous harmful illnesses are seeing their ranges greatly expand as the world heats up.

Mosquito-borne infection is an ancient and well-known threat to humankind. But it has thankfully been relegated to warmer climates. Despite knowing little about mosquito-borne Malaria, the Roman aristocrats of antiquity did know they could avoid infection by retreating to villas in the cooler hills. Away from where mosquitoes were plentiful. Unfortunately, the climate crisis is driving heat, and the mosquitoes that come with it, both uphill and into higher latitudes.

A single populous species of mosquito — Aedes aegypti — can spread four serious illnesses. They include Dengue Fever, Zika virus, Chikunyunga and Yellow Fever. As global heating continues to be driven by fossil fuel burning, the range of this mosquito is expected to greatly expand. How much depends on how rapidly we halt fossil fuel burning and transition to clean energy (or not). But a business as usual (worst case) fossil fuel burning scenario in which the clean energy transition continues to be hobbled will bring this so-called jungle fever carrier to the Arctic by the 2080s (see image above).

There are over 3,500 species of mosquito. Most are relegated to warmer climates. In addition to the illnesses mentioned above, these insects also carry Malaria and West Nile virus among many others. And as the climate heats up, their range and their ability to transfer diseases among humans will expand.

But mosquitoes are not the only disease reservoir and disease vector species now on the move as a result of the disruption caused by climate crisis. There are many. Some which we probably don’t yet know about.

Receding Cold

If tropical heat spreading northward bringing with it flights of mosquitoes and displacing other disease carriers presents one illness expansion problem, the ongoing thaw of cold regions presents another. In particular, there is evidence that the Arctic has locked away numerous ancient illnesses that could be released in the thaw produced by climate crisis.

The Variola virus which causes Smallpox may well be sequestered in the various graves and burial mounds scattered throughout the Asian and European north. A study conducted in the 1990s detected fragments of smallpox DNA in the remains of Stone Age humans as well as people who were known to have died from smallpox during the 19th Century. Though smallpox was considered eradicated from human beings, long deceased humans frozen in the Arctic may serve as a reservoir that results in potential new infections. If such a reservoir exists, the Arctic thaw produced by the climate crisis will disturb it.

Other pathogens that may still be harbored by dead humans frozen the Arctic includes the 1918 Spanish flu (H1N1) which was found in frozen regions of Alaska. In 2007, scientists discovered Spanish flu RNA in the body of an Inuit woman who’d been buried for 75 years in the permafrost.

Anthrax is a bacteria-caused infectious disease that typically afflicts herd animals such as sheep and reindeer. But Anthrax can pass to humans that are exposed to the bacteria. In 2016, 2,000 reindeer became infected with Anthrax in the Yamal Peninsula region of Siberia. Nearby, it is thought that a reindeer killed by anthrax decades before thawed out, spreading the bacteria into the lands where the reindeer grazed. These reindeer then spread the illness to a number of human beings, including a 12 year old boy who died.

The potential for the release of both known and other as-yet unknown infectious agents from the thawing regions of our world have generated concern among top researchers. Jean-Michel Claverie a professor of microbiology at Aix-Marseilles University recently noted to BBC:

“Following our work and that of others, there is now a non-zero probability that pathogenic microbes could be revived, and infect us. How likely that is is not known, but it’s a possibility. It could be bacteria that are curable with antibiotics, or resistant bacteria, or a virus. If the pathogen hasn’t been in contact with humans for a long time, then our immune system would not be prepared. So yes, that could be dangerous.”

A Context of General Disturbance

Overall, it is likely that there are more numerous climate influences to disease transfer than mere heating and thawing. The general disturbance to the natural world generated by more extreme fires and floods, by instances of flash drought, and even by the mechanism of rising seas is likely to displace more disease reservoirs, creating previously unknown illness transmission potentials.

As far as our general scientific knowledge of illness related to or influenced by the climate crisis at this time, what we see now is likely the tip of the proverbial iceberg. And, as with all things climate crisis related, we require more research, more knowledge-sharing, more general public support of scientific discovery to pull back the veil on this particular new threat. So in conclusion of this chapter on the climate crisis relationship to human illness, we’ll depart with a statement from the World Health Organization:

Changes in infectious disease transmission patterns are a likely major consequence of climate change. We need to learn more about the underlying complex causal  relationships, and apply this information to the prediction of future impacts, using more complete, better validated, integrated, models.

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

Zika and the New Climate Dystopia — Human Hothouse as Disease Multiplier

As of today, authorities in Brazil, Colombia, Jamaica, El Salvador and Venezuela were urging women to avoid getting pregnant… It is unthinkable. Or rather, it is something out of a science fiction story, the absolute core of a dystopian future. — Bill McKibben in a recent statement on global warming and the now pandemic Zika virus.

******

There are a plethora of diseases out there. Diseases we don’t know about. Diseases locked away in far-off, rarefied corners of the world. Diseases that operate in small niche jungle environments. Diseases that live in only cave systems or within a single species. Diseases that were locked away millions of years ago in the now-thawing ice. Diseases that, if given a vector — or a means to travel outside of their little rarefied organic or environmental niches — can wreak untold harm across wide spans of the globe.

Countries with Reported Active Zika Transmission

(Countries with reported active Zika transmission. Until recently, Zika flare-ups had been isolated to Central Africa and French Polynesia. Now the virus is a global pandemic with World Health Organizations authorities concerned infections could top 4 million. Image source: The CDC.)

Such was the case with the once humble Zika virus. Discovered in 1947 in Central Africa, the disease first only existed in monkeys. The virus took 7 years to make the leap into humans in 1954. But, at first, symptoms were only mild and for most of the history of this disease it was considered to be a less harmful form of the Dengue Fever Virus — to which it is closely related. The virus, at first, appeared only to result in fever, headaches, rash and back pain — if any symptoms appeared at all. It would take much longer for the devastating and horrific after-effects of an, at first, seemingly harmless virus to begin to show up.

Until 2007, when the virus began to grow to its current pandemic levels, it was mostly isolated to Central Africa and a region of French Polynesia in the Pacific. Both areas are among the warmest and wettest in the world. Both featuring very large and persistent populations of the kinds of mosquitoes most suited for the transmission of this, now widely-feared, illness.

An Issue of The Expanding Range of Disease Vectors

In epidemiology parlance, a vector is a disease carrier. In the case of Zika, the primary carrier is the mosquito. In total, seven species of the Aedes variety of mosquitoes are known to carry Zika.

Under normal climate conditions, the ranges of these disease-bearing insects would tend to remain rather stable. But that’s not the case in the current world. Since 1880, the world has been warming and the extents of disease vector mosquitoes has been expanding. Under the current regime of 1 C temperature increase over the past 136 years, Aedes aegypti — one of the chief transporters of the Zika virus — has expanded its range on out of the tropics and into increasingly higher Latitudes.

Global_Aedes_aegypti_distribution

(Global Aedes aegypti distribution in 2015 — red indicates highest frequency, blue indicates zero frequency. Aedes aegypti is a disease vector for viruses like Dengue and Zika. As the globe has warmed, their range has been expanding into ever higher Latitudes. Image source: Aedes aegypti Distribution.)

But not only is the global extent of these disease carriers expanding — so is their persistence in the regions into which they’d previously occupied. Regions that may have seen only one or two weeks out of the year in which female, Zika infected, mosquitoes were active may now experience a month or two of exposure. And regions in which the mosquito was active for only a few months may now see active, disease-bearing populations for half of the year or more.

It is this increasing duration and expansiveness of disease vector exposure that is one of the most dangerous epidemiological impacts of climate change. Not only does climate change enable the movement of diseases out of previous isolation in remote reservoirs. It also enables an ever-broadening range of transport as the areas in which disease-carrying species are adapted to live dramatically expands both in terms of space and in terms of time of exposure.

It’s as if we decided to load up trillions of mosquitoes with what amounts to biological live rounds and then gave them the ability to unload that deadly ammunition over broader and broader expanses of the globe. That’s basically what you get when you warm the world. An expansion and global invasion of hitherto unknown illnesses spread throughout the world by vectors like the mosquito.

Zika’s Viral Explosion Occurs During Hottest Year on Record

Returning to our tale of the Zika virus’s expansion during 2007 through 2016, we find that Zika during this time-frame had leapt out of its traditional 20th Century range and expanded coincident with the spread of Aedes variety mosquitoes along the warming and moistening climate bands. In 2007, the first leap outside of Central Africa and French Polynesia occurred in Yap — a part of the Federated States of Micronesia.

The epidemic range then again expanded through 2014 into Easter Island, broader Polynesia, the Cook Islands, and New Caledonia. The geographic expansion of this illness along the Pacific Island chains indicates that Zika’s increased virulence likely sparked from the French Polynesian strain and not from the strain in Africa.

Then, in 2015, coordinate with the hottest global temperatures on record, Zika leapt out of its Pacific Island basin environmental confines and spread into Brazil and the Caribbean. The virus subsequently spread through a broad section of Central and South America. As of yesterday, travel warnings of possible exposure to the Zika virus included this list of 22 countries:

Barbados, Bolivia, Brazil, Cape Verde, Colombia, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Samoa, Suriname, and Venezuela.

By today,  the World Health Organization was issuing warnings that as many as 4 million people may end up being infected before the most recent outbreak is finished.

The New Climate Dystopia — We are Now Telling Women Not to Have Children

Like many viral fevers, Zika attacks the nervous systems of those it infects. And though initial onset symptoms may seem mild, with up to 80 percent of those infected showing no symptoms at all, the virus may cause severe longer-term damage to both the unborn and to vulnerable individuals. For as infection rates for the virus increased what were suspected to be related instances of a kind of temporary paralysis called Guillian Barre Syndrome and a terrifying shrinking of the heads of unborn infants called microcephaly also spiked.

Microcephaly

(A spike in microcephaly rates — a tragic shrinking of the heads of unborn children as a result of viral damage to the nervous system — among infants in regions of Zika virus outbreak has raised global concerns about the virus’s ongoing impact. Most particularly, women in an expanding number of countries are now being asked to refrain from having children for months or even years. Image source: The CDC.)

From BBC today:

The virus, which has no symptoms 80% of the time, is blamed for causing stunted brain development in babies. About 3,500 cases of microcephaly have been identified in Brazil so far. And medical staff in Recife, a state capital in north-east Brazil, say they are struggling to cope with at least 240 cases of microcephaly in children.The city’s Health Secretary, Jailson Correia, a specialist in tropical diseases, told the BBC he and others needed “to fight very hard”.

These are profoundly terrible impacts. Ones that were not initially expected from a virus that at first seemed so innocuous. And it’s this threat of Zika-spawned microcephaly among infants that is spurring everything from travel warnings to the hitherto unprecedented measure of some countries requesting that their human populations take the extreme step of avoiding pregnancy.

As of Monday authorities in Brazil, Colombia, Jamaica, El Salvador and Venezuela were urging women not to get pregnant. The pregnancy moratorium — which is voluntary — ranges in duration from a few months to two years in the case of El Salvador. And the reason for the requested moratorium is sadly practical. Authorities in these countries are now forced to choose between asking women to avoid pregnancy or having their healthcare systems overwhelmed by infants suffering from microcephaly.

With a vaccine likely 10-12 years away for Zika, with 4 million cases expected in the current outbreak, and with the range of Aedes type mosquitoes who carry the virus continuing to expand on the back of a human-forced warming of the globe, we are sadly just at the beginning of this particular tragedy. An event that, as Bill McKibben noted in The Guardian earlier this week, has leapt fully into the realm of dystopia.

A Profound Dislocation For Humankind

Microcephaly among infants is both tragic and terrifying. Its impact strikes at the very heart of what it means to be a human being. If a virus, driven to far-flung regions by the heating of the world through fossil fuel burning, is able to cripple our children while still in the womb, our sense of security is shattered as we witness heart-breaking brutality. It’s the kind of thing so terrible it couldn’t come from the human imagination. Which is why, when we witness it, we experience a strange sense of dislocation. A surreal sense that all is not right. Like the moment after the car hit the telephone pole, the moment you’re still flying through the air flung free of the vehicle. The moment just before the inevitable impact with the pavement.

But the impact, sadly, does come. Not only are we turning many of the species of this world into climate orphans. Into creatures without a safe space in which to live and thrive, we are also doing it to ourselves. For the children of Zika are climate orphans too. The tragic victims of an expanding range of environmental conditions that are hazardous to human life. And Zika is but one example of the deadly diseases, extreme weather, sea level rise, glacial collapse, ocean death, and crop disruption we are now forcing upon the human habitat. A habitat we are rendering less livable for ourselves and pretty much everything else.

That’s what terminal dislocation means — to be forceably ejected. To be suddenly introduced into a very hostile environment in which survival, and in this case reproduction, is suddenly a crap shoot. For human beings, this is a profound dislocation. One that makes the world we’re living in now seem all-too-alien. For we’re not living in the world we are used to. And the one we’re making is both terrible and tragic. And, in all honesty, we desperately need to stop the damage before some other very big, or terrible, or essential thing breaks free.

Links:

The Zika Virus Foreshadows Our Climate Dystopian Future

About Climate Change and Vector-Borne Diseases

The CDC

The Zika Virus

Mosquito Borne Zika Virus Spreading Explosively

Aedes Aegypti

UCAR: Climate Change and Vector-Borne Disease

Brazilian City Sees Spike in Microcephaly Cases

Facts about Microcephaly

2 C Warming Increases Mosquito Population by 50 Percent

Hat tip to Umbrios

Hat tip to Colorado Bob

Hat tip to DT Lange

Hat tip to RedSky

%d bloggers like this: