Add Newly Discovered Ancient Giant Viruses To List Of Pathogens Benefiting From Climate Change

CREDIT: AP/ Julia Bartoli, Chantal Abergel

This electron microscope image provided by researchers in March 2014 shows a section of a Pithovirus particle, dark outline, inside an infected Acanthamoeba castellanii cell. The length of the particle is about 1.5 microns with a 0.5 micron diameter. Researchers have revived the virus, which is more than 30,000 years old, after finding it in the permafrost of northeast Siberia.

After at least 30,000 years trapped in time, a frozen virus has thawed from a deep layer of Siberian permafrost. This is no ordinary virus — it is the biggest virus ever found on Earth, and thought to be part of a new type of “giant virus” that can be larger than many bacteria or even cells, and is visible in a normal microscope. With climate change warming the planet and taking the “perma” out of permafrost in many polar regions, scientists may begin to unearth more previously undiscovered viruses, not all of which will be as benign as this new one, dubbed Pithovirus sibericum. It poses no danger to people, infecting only one-celled creatures known as amoebas.

A team led by Jean-Michel Claverie and Chantal Abergel of Aix-Marseille University in Marseille, France, published their discovery in an article in the Proceedings of the National Academy of Sciences.

“Familiar viruses are tiny and have few genes,” reported the New York Times. “The influenza virus, for example, has 13 genes and is about 100 nanometers across. But giant viruses, which typically infect amoebae, can be 1,000 times bigger and have more than 2,500 genes.”

According to Abergel, sixty percent of the new viruses’ gene content doesn’t resemble anything on earth. The scientists working on the research suspect that the virus may have been been a parasite to life forms more common in earlier days of life on earth.

However, Claverie is worried about the implications of this type of discovery for present-day life on Earth. “It is a recipe for disaster,” he told BBC News. “If you start having industrial explorations, people will start to move around the deep permafrost layers. Through mining and drilling, those old layers will be penetrated and this is where the danger is coming from.”

For example, Claverie said that ancient strains of smallpox, supposedly eradicated for over three decades, could resurface, wreaking havoc. “This might be the Gulag’s revenge,” he said. “Many of those people died from disease and they weren’t buried very deep.”

Curtis Suttle, a microbiologist at the University of British Columbia who did not participate in the study, told The Verve that climate change is the real threat. “I would be much more concerned about the hundreds of millions of people that will be displaced by rising sea levels than the risk of being exposed to pathogens from melting permafrost.”

Climate change is impacting pathogens in other ways than melting permafrost. A new study by a team of researchers from the Center for Tropical Research at UCLA’s Institute of the Environment and Sustainability found that as the climate warms West Nile virus will continue its recent spread across the globe. The results suggest that higher temperatures and reduced precipitation will lead to a higher probability of West Nile Virus spreading. The virus first left Africa about 15 years ago, and in 2012 there were more than 5,500 cases reported in the U.S. — though 80 percent of infections are subclinical, meaning they yield no symptoms.

“In California, we estimate approximately 68 percent of the state’s area will have an increase in the probability of West Nile virus by 2050,” said Ryan Harrigan, a postdoctoral researcher who worked on the report.

According to experts interviewed by the USA TODAY, three trends contribute to America’s changing disease map:

“The first is overall warming, which makes new areas hospitable to the animals and bugs that can carry disease. The second involves increased extreme weather events such as drought, rainstorms and flooding, which create situations where diseases and insects that carry them can flourish. Finally, Americans are increasingly moving to areas close to wilderness, where they are more exposed to these disease-carrying creatures.”

Melting permafrost releasing previously undiscovered pathogens is not the primary threat of that phenomenon either — rather the greenhouse gas emissions released by the process that contributes to climate change and associated heat waves, droughts and other extreme weather events.


CREDIT: National Snow and Ice Data Center

“Nearly a quarter of the Northern Hemisphere’s land surface is covered in permanently frozen soil, or permafrost, which is filled with carbon-rich plant debris,” wrote Michael D. Lemonick at Climate Central, last month. “Enough to double the amount of heat-trapping carbon in the atmosphere if the permafrost all melted and the organic matter decomposed.”

Previous studies estimated that melting Arctic permafrost will release enough greenhouse gases to boost global temperatures by up to an extra half a degree Fahrenheit by 2100, but a new paper published in Science has found that the melting could come sooner and be more widespread than previously thought. The study found that if temperatures rise 2.5°F (1.5°C), permafrost across much of northern Canada and Siberia could start to weaken and decay.

The impacts of permafrost thaw are already being felt on the ground in Alaska where the changing surface temperatures are causing earth to shift and disturb building and road foundations. Alaska’s temperatures are rising about twice as fast as in the contiguous United States.

Vladimir Romanovsky, who runs the University of Alaska’s Permafrost Laboratory in Fairbanks, told USA TODAY that the pace of permafrost thawing is accelerating, and that he expects widespread degradation to start within a few decades.