Climate Change and Dormant Viruses | Pavittarbir Singh Saggu

by Pavittarbir Singh Saggu*

Because of climate change, permafrost is thawing, releasing viruses and bacteria that have been dormant for thousands of years, posing potentially catastrophic risks to humans and ecosystems.

When a strange illness struck the Siberian tundra during the 2016 summer heatwave, a group of reindeer herders became ill and it also caused the loss of 2500 reindeer as well as a 12-year-old boy. Siberian plague, which was last seen in 1941 in the region, was thought to be the cause of this illness. However, anthrax was found to be the cause of the illness and found that it came from a reindeer carcass that had died of anthrax 75 years earlier and had been exposed due to melting snow as a result of rising temperatures.

As the climate catastrophe worsens, this reemergence of viruses and bacteria could become more common. A million years or more is possible for bacteria to survive in permafrost because the conditions are favorable. Cold, oxygen-free, and dark conditions make permafrost ideal for preserving bacteria and viruses. RNA fragments from the 1918 Spanish flu virus have been found in mass graves in Alaska’s Tundra by scientists and smallpox and bubonic plague are likely buried in Siberia, indicating the possibility that these agents could be released in the future due to rising temperature.

It was hypothesized in 2011 that diseases widespread in the 18th and 19th centuries could reappear as a result of melting permafrost, particularly near cemeteries where the victims of these diseases were interred. Scientists from Novosibirsk’s State Research Center of Virology and Biotechnology have tested the remains of Stone Age people discovered in southern Siberia, as well as samples from the bodies of men who died during viral epidemics in the nineteenth century and were buried in the Russian permafrost, in a project that began in the 1990s. According to the researchers, a smallpox-related DNA fragment was detected in some of the remains. In a study, the researchers in 2005 revived bacteria that had been frozen in an Alaskan pond for more than 30,000 years, back when woolly mammoths roamed the Earth. Bacteria began swimming unhindered as the ice melted. The 8-million-year-old bacterium was able to be revived two years later by scientists in Antarctica that had been frozen under a glacier. Fortunately, after being frozen in permafrost, not all bacteria can come back to life. Toxins such as anthrax produce spores that may withstand being frozen for over a century. Tetanus and the bacteria that cause botulism are two similar bacteria.

According to a 2009 study, residents in the Arctic rely on subsistence hunting and fishing for food, as well as a suitable temperature for storing food. This type of food storage involves ground air-drying, storing it underground, and storing it near permafrost. In temperatures above 4 degrees Celsius, the bacteria that causes botulism is active. Therefore, as the climate warms, the risk of food-borne botulism could increase. Due to faster temperature increases in the Arctic than anywhere else in Northern Hemisphere, further rapid melting is expected to occur soon. The Arctic has warmed by 0.75 degrees Celsius in the last decade, while the Earth as a whole has warmed by 0.8 degrees Celsius in 137 years.

The Zika Virus is a mosquito-borne virus spread mostly by Aedes mosquitos that causes fever, muscle and joint discomfort, and headaches. As the temperature warms, so will the movement of disease-carrier species. Infection with the Zika virus while pregnant can result in microcephaly in the baby and, in the worst-case scenario, miscarriage. Dengue and chikungunya fevers are also spread by these mosquitos. Although these mosquitos are mostly found in tropical regions, rising temperatures may encourage them to spread to other regions as well. The Zika Virus outbreak in Brazil from 2014 to 2016 was the subject of a 2017 study. This study claimed that around 200,000 Zika virus cases had been confirmed by the end of 2016 in Brazil. The infection was said to have been brought into the country during the 2014 World Sprint Championship canoe competition in Rio de Janeiro, which attracted people from French Polynesia into the country, causing Zika to spread. After settling in Brazil, the virus expanded throughout Latin America and the Caribbean, eventually affecting every country where the Aedes aegypti mosquito was present.

Increasing air temperature will result in faster thawing as the climate catastrophe continues. Vibrio Cholerae (cholera bacteria), multiplies at higher temperatures and spreads faster. The melting of the soil could contaminate water supplies, causing the spread of water-borne diseases such as cholera and others. There is no way for us to know the entire degree of this without experiencing it, even if we are aware of the dreadful and life-threatening diseases and viruses that could come back to life with the advancement of the climatic crisis. Before the emergence of unknown and horrifying diseases, humanity must reduce the climate problem.

* (Author: Pavittarbir Singh Saggu, Research Scholar, Panjab University, Chandigarh)