Just in case you’ve been getting too much sleep, you may be interested to know that researchers have uncovered a new potential danger: the effects of climate change on deadly, disease-causing microbes. There are millions of different types of microbes. Most are harmless to humans, or even helpful to us, but many are pathogenic. Pathogenic microbes can be bacteria, viruses, parasites, fungi, or protists (an amoeba is an example of a protist) and they are responsible for some of the most terrifying illnesses on the planet, like cholera, salmonella, malaria, and anthrax. While each species has specific requirements for the environment they like to live in, many pathogens like warm, humid climates, especially in places with poor sanitation and drinking water. They can live in water, food, soil, fecal matter – pretty much anything moist and warm.

For example, you may have heard of Vibrio cholerae, the bacterium that causes cholera, a diarrheal disease.

A cholera bacterium. Cute little guy, no?

Cholera kills you via dehydration, but before you go, you will expel vast amounts of liquid poop. Cholera killed at least 143 million people per year during a 26-year period. But what about a viral disease that causes diarrhea? Perhaps you have heard of Norovirus, a virus that spreads when you ingest fecal matter – most people hear about outbreaks on cruise ships. Yeah, I mean that you get Norovirus by eating food or drinking water contaminated with infected poo.

Definitely not.

Many of these kinds of pathogens are spread in contaminated food or water. In fact, the World Health Organization estimates that in developing nations, more than 50% of the people who live in urban areas are eventually affected by diseases related to unsafe drinking water. Poor sanitation, unsafe drinking water, and a warm moist environment, will make many of these buggers super happy and any humans that encounter them super… likely to poop.

Enter climate change. As the planet warms, we can expect that the warm parts of the planet are going to expand outward from the equator, meaning that the climate that our microbe friends enjoy is going to be moving more northerly and southerly. If you were a pathogenic microbe, and you were suddenly able to migrate into new areas – you know, find new stompin’ grounds – wouldn’t you? Especially if your old territory became much too hot for you to survive there. Diseases, like cholera and malaria, that typically live in warm, developing nations could be moving into Europe and the lower part of the United States. However, that doesn’t mean we will all die of dysentery, like in The Oregon Trail.

Oh no!

One important reason we don’t see these diseases in industrialized countries is because we have modern water treatment and sanitation facilities. Industrialized nations also have treatment plans for critters that carry diseases, like ticks or mosquitos.

Moving day.

Water treatment doesn’t always get every pathogenic microbe, but our climate is inhospitable to most of them which helps keep them under control. For now. If that isn’t enough to save us, we have modern medicine. Antibiotics and anti-viral medicines that may not be readily available in poorer nations, but they can be prescribed by your doctor in industrialized nations.

Now let’s head to the icy north. The second of those potential new climate change/pathogenic microbe threats I mentioned at the beginning is the possibility of emerging zombie pathogens. Pathogenic microbes that were frozen in soil and water (or in long-dead carcasses) thousands of years ago could become viable again if the conditions are right. Temperatures are warming at an alarming rate, from one perspective, but from a microbe’s perspective, the temperatures are warming just slowly enough for a gentle thaw. That’s exactly what most pathogenic buggers need to become viable again once exposed to the environment. When an infected human or animal dies and is buried in a cold climate, the ground freezes and layers of sediments, snow and ice are deposited on top of the grave. As the climate warms, the ice and permafrost thaw, releasing any microbes that survived.

In an article from National Public Radio, Zac Peterson described his research, which involved working with perfectly frozen seal carcasses in northern Alaska. The seals thawed into a gooey mess and Zac spent time kneeling in that goo. The knee that was in contact with the goo became red and inflamed. He had contracted a case of seal finger disease, a bacterial infection known to infect seal hunters. Zac had only been working with 800 year old, previously frozen seals. There have also been cases of frozen reindeer dying from anthrax in Siberia and becoming buried in the permafrost. 70 years later, the ice thawed during a heat wave in 2016. The infected reindeer were also able to thaw, decompose, and release the Anthrax spores into the environment. Lot’s of people got sick and one young boy died from the infection.

It sounds pretty dire, but don’t worry! The wonders of modern science and medicine will save us again! Or at least they should. Modern drugs and medical techniques should be able to contain any of pathogens that are viable. Couple that with good hygiene and modern water and sanitation facilities and those nasty buggers don’t stand a chance! Unless the emerging pathogen is something we don’t have an available vaccine or a current treatment for….

Variola Virus – The cause of smallpox

For example, one pathogen known to be in the Siberian tundra is smallpox. Smallpox is caused by the highly contagious variola virus. It hasn’t infected a human since 1979, when the World Health Organization listed it as an eradiated disease. There is worry that, should a viable variola virus find its way from its thawing grave into a warm host, we may not have any defense against it at first. We have not needed to vaccinate people against smallpox in decades, so young populations in many parts of the world don’t have any immunity. People still die from the flu and we distribute vaccines for that virus. If smallpox found its way into a human host, millions of people could die before we are able to get enough people vaccinated to slow the spread.

The possibility of disease-causing microbes migrating into new territory or emerging from their graves in the frozen tundra may sound like a premise of a new outbreak movie, but  given that the probable (and currently observable) effects of climate change are dramatic enough on their own, this new problem is sort of like throwing a diseased match on a burning planet. There is cause for concern, but we also have science and human ingenuity on our side. And since we know the threat, there is yet time to defeat it!

References

Climate change and infectious diseases. (n.d.). Retrieved January 30, 2018, from http://www.who.int/globalchange/climate/summary/en/index5.html

Doucleff, M. (2018, January 24). Are There Zombie Viruses In The Thawing Permafrost? Retrieved January 30, 2018, from https://www.npr.org/sections/goatsandsoda/2018/01/24/575974220/are-there-zombie-viruses-in-the-thawing-permafrost

Frequently asked questions and answers on smallpox. (n.d.). Retrieved February 22, 2018, from http://www.who.int/csr/disease/smallpox/faq/en/

Meyer, R. (2017, November 06). The Zombie Diseases of Climate Change. Retrieved January 30, 2018, from https://www.theatlantic.com/science/archive/2017/11/the-zombie-diseases-of-climate-change/544274/

University of Liverpool. (2017, August 2). Europe’s most dangerous pathogens: Climate change increasing risks. ScienceDaily. Retrieved January 30, 2018 from www.sciencedaily.com/releases/2017/08/170802082915.htm

Unsafe drinking-water, sanitation and waste management. (n.d.). Retrieved January 31, 2018, from http://www.who.int/sustainable-development/cities/health-risks/water-sanitation/en/