Sunday, March 25, 2018

Global Warming and the Resurrection of Dormant Diseases

When one thinks of climate change and its consequences, images of floods and droughts come to mind, soon followed by those of rising seas that engulf coastlines and cities.  These events are, of course in the future.  It is necessary that we be reminded that although climate change is a gradual thing, its effects are evident here and now.  Areas in southern Florida are already seeing chronic flooding at high tides.  The disappearance of sea ice on Alaska’s coast is destroying the habitat for those who live there.  The more extensive melting of permafrost with rising temperatures is causing a great deal of damage to the state’s infrastructure.  An article in Harper’s Magazine, Cursed Fields, by Noah Sneider points out that melting permafrost can do more than just ruin the foundation of a building or a road, it can release the agents of diseases that have long lay dormant in the ice.

Sneider tells of an incident that occurred on the Yamal Peninsula which extends north from Russia’s northern border.  This area has long been inhabited by a people who have based their existence on tending herds of reindeer.  The products harvested from these animals provide food, clothing and shelter, as well as articles for trade.  In the long cold winters, the region freezes solid.  During the summer months the temperature can get up to about 60 degrees Fahrenheit.  However, warming of the environment is proceeding faster at the northern reaches of our planet and in 2016 a troubling event occurred.  The summer of 2016 was especially warm with temperatures reaching to about 100 degrees Fahrenheit.  This causes much more than normal melting in the surface permafrost layer.

“Normally, the upper layer of permafrost melts about twenty to thirty centimeters; in 2016, it receded more than a meter and a half in certain areas of Yamal.”

These unusual conditions were accompanied by an illness that began killing reindeer.  The Russian government sent experts up to investigate.  What they discovered was that the animals were dying from anthrax, a disease that they thought had been eradicated from the region because its last known instance occurred about 75 years ago.  Anthrax is a nasty, durable, bacterial spore that can lie dormant for long periods.  It was once a major threat to herd animals until Louis Pasteur developed a vaccine that was effective against it.  In Yamal, vaccination is difficult and expensive and fell out of practice.

“In Yamal, the authorities were certain that they had defeated anthrax long ago. The last major outbreak took place in 1941. Surveys of some 250,000 soil samples over the past twelve years had revealed no signs of dormant spores. The regional government had stopped vaccinating reindeer in 2007 — it was a costly process that required wrangling the vast herds across a territory larger than France. ‘An extended period of good fortune leads people to let their guard down, their sense of worry and danger disappears, and they think that since everything has been good, it will continue to be good,’ mused Yuri Selyaninov, the microbiologist whose laboratory confirmed the anthrax diagnosis.”

The official explanation for the reemergence of anthrax in the region places the blame on climate change and the warming of the local environment.

“Climate change also lies behind the most credible explanation for anthrax’s return. You might call it the zombie theory. It goes something like this: The corpses of reindeer infected with the disease decades or centuries ago were preserved in the upper layers of the peninsula’s permafrost, keeping the resilient spores alive. As temperatures have soared, the permafrost has begun to thaw ever deeper, exposing the ancient grave sites and giving the spores a pathway back to the surface, where they can once again rise up to infect the living.”

Sneider points out that a warning was issued in 2011 that this sort of event was likely to occur.  Boris Revich, an environmental epidemiologist at the Russian Academy of Sciences made this statement.

“As a consequence of permafrost melting, the vectors of deadly infections of the eighteenth and nineteenth centuries may come back, especially near the cemeteries where the victims of these infections were buried.”

In case one chooses to ignore events occurring in the farthest reaches of northern Russia, Sneider points out that excessive melting of permafrost is also happening in Alaska, and numerous scientists and agencies are concerned.

“Recent research has uncovered a number of specific threats. From mass graves in the Alaskan tundra, scientists have uncovered fragments of the virus that caused the 1918 outbreak of the Spanish flu. In 2013, the French microbiologists Jean-Michel Claverie and Chantal Abergel discovered still-active viruses in a 30,000-year-old slice of Siberian permafrost. Though their sample could not affect humans, their study suggests that other, more infectious viruses may be lurking. Some frozen microbes may even carry diseases that our immune systems no longer know how to fight. Specialists also caution that devastating eradicated diseases such as smallpox could be preserved in the ice. Many researchers see the Yamal outbreak as a sign of things to come. ‘It’s a warning of sorts that the situation with preserved infections infiltrating our modern world may get much worse if we do not address the problem,’ argued Boris Kershengoltz, the chief of research at the Russian Institute for Biological Problems of the Permafrost Zone.”

The Spanish Flu of 1918 has been of particular interest because it was so deadly.  Gavin Francis provides some relevant background in an article in the London Review of Books: The Untreatable.

“This year marks the centenary of Spanish flu, the most deadly pandemic in human history. It is estimated that five hundred million people contracted it – a third of the global population in 1918 – and that between fifty and a hundred million of them died. Asians were thirty times more likely to die than Europeans.”

“The spread of Spanish flu was quickened by the railway and steamer lines that girdled the planet, starkly illuminating global inequalities in security, nutrition and access to medical care. In India 6 per cent of the population died; in Fiji 5 per cent; in Tonga 10 per cent. In Western Samoa, for reasons that aren’t entirely clear, more than 20 per cent of the population died. Even harder hit were the Alaskan Inuit, with a death rate between 25 and 50 per cent: in some small Alaskan communities everybody died.”

There has long been interest in studying this flu virus and trying to understand why it was so incredibly contagious.  The logical place to look for samples of the virus was within corpses of those who had died and been buried within Alaska’s permafrost.  Finally, success came and scientists could study it in detail.

“….a Swedish-Iowan pathologist, Johan Hultin, travelled to Alaska and sampled lung tissue from graves at Brevig Mission, one of the Inuit communities badly affected by Spanish flu. The graves were relatively well preserved in permafrost….[he] exhumed an obese woman whose lungs had been preserved in fat. Enough flu virus was recovered from the lungs to be sequenced, and the results, published in Nature in 2005, suggested that the 1918 virus was avian in origin, but that a mutation had rendered it fatally adept at infecting mammals.”

Curious scientists would also wish to verify the virus’s lethality.

“When the reconstituted virus was given to mice under barrier conditions the mice lost 13 per cent of their body weight and produced forty thousand times more infectious particles than mice with ordinary seasonal flu. Six days after infection, all the mice were dead.”

The deadly virus is now being stored at a facility in Atlanta, Georgia.  Should it reemerge in the population, modern healthcare would limit its effects, but tens of millions of people are estimated to die.

“The virus is currently held in a high-security facility in Atlanta, Georgia. In 2016, around 1.7 million people died from tuberculosis, around a million from HIV/Aids, and around half a million from malaria. Computer modelling suggests that if the 1918 H1N1 virus were to break out of the facility in Atlanta it would cause around thirty million deaths.”

There are two things one should take from this discussion.  First, influenza is dangerous, and it is only a matter of time before a similarly lethal strain arises.  Second, climate change is already having serious consequences.

The interested reader might find the following articles informative:

Global Warming Comes to Alaska

Putting Climate Change in Perspective

Ground Zero for Sea-Level Rise: South Florida

Global Warming and the Holocaust’s Warning: It Can Happen Again

Disease and the Human Outbreak

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