Threat Multiplier: Climate Change Brings Deadly Health Surprises

May 6, 2017


A baby semi-slug is shown on a nickle. Snails, slugs and certain other animals (including freshwater shrimp, land crabs, and frogs) can become infected by ingesting the larvae of the rat lungworm. — Hawaii Department of Health photo

Once again, climate change is a threat multiplier in unexpected ways.

I’ve covered the spread of brain eating amoebas several times. 
There’s more. So much more.


Throughout history, humans have existed side-by-side with bacteria and viruses. From the bubonic plague to smallpox, we have evolved to resist them, and in response they have developed new ways of infecting us.

We have had antibiotics for almost a century, ever since Alexander Fleming discovered penicillin. In response, bacteria have responded by evolving antibiotic resistance. The battle is endless: because we spend so much time with pathogens, we sometimes develop a kind of natural stalemate.

However, what would happen if we were suddenly exposed to deadly bacteria and viruses that have been absent for thousands of years, or that we have never met before?

We may be about to find out. Climate change is melting permafrost soils that have been frozen for thousands of years, and as the soils melt they are releasing ancient viruses and bacteria that, having lain dormant, are springing back to life.


The Brain eating amoebas are not the only threats climate change brings


In fact, climate change is already affecting personal human health around the world. This subject was the focus of a summary report just published by the Medical Society Consortium. What I really liked about this report is that it breaks down some of the key impacts by region. Unfortunately, the report is limited in scope to the USA. However, the general conclusions and trends can be illuminating for people outside the USA as well.

What was also welcome is that this report was prepared by physicians (not climate scientists) of major medical societies and the conclusions are based on the best available and current information of both the climate and health fields.

So what did they find? Perhaps most importantly they find that climate change is already affecting our health. This isn’t a future problem for the next generation. It is a problem that is present and growing. They also report that some populations are more susceptible to climate change effects. Among the most vulnerable groups are children, student athletes, pregnant women, elderly, people with chronic health conditions, and the impoverished. A third key takeaway is that the problems will get much worse as climate change continues.

The study reports that if you live on the West Coast, wildfires, extreme temperatures, poorer air quality, extreme weather events, and agricultural risks are occurring. On the East Coast, you can add vector-borne diseases as a risk area. The central USA region is also similarly being affected.

For instance, with respect to extreme weather, the report correctly notes that the frequency and severity of some weather events such as heavy downpours, floods, droughts, and major storms are increasing. This harms our health because these events can cause direct injury and death as well as displacement. Extreme weather can also harm vital infrastructure like communication systems, homes, and reduce the availability of clean water and food. Finally, extreme weather can lead to acute outbreaks of infectious disease while at the same time reducing access to health care.

Air pollution is another example area. Climate change is affecting air quality in many ways, including increasing chemical reactions in surface air (air we breathe), increasing pollen, and leading to more forest fires. Lower air quality obviously affects people with breathing problems (such as asthma and allergies). It can prolong the pollen seasons and worsen allergy symptoms. Less obvious effects like increased humidity and more heavy rainfalls can exacerbate air-quality problems indoors through mold growth for instance.

One issue I was not aware of was the threat of climate change to nutrition. Increases in carbon dioxide actually result in a lowered nutritional value of grown food such as wheat, rice, barley, and potatoes. This occurs because plants produce less protein and more sugars/starches in a carbon rich atmosphere. Plants also are less effective at taking in essential soil minerals. This is all in addition to the threats to our food system by droughts and extreme weather. We’ve certainly seen very severe droughts in the USA (2011 in Oklahoma and Texas, 2012 in Midwest USA, and 2012–2016 in California) that have caused severe problems in the agricultural industries.

BBC again:

In August 2016, in a remote corner of Siberian tundra called the Yamal Peninsula in the Arctic Circle, a 12-year-old boy diedand at least twenty people were hospitalised after being infected by anthrax.

The theory is that, over 75 years ago, a reindeer infected with anthrax died and its frozen carcass became trapped under a layer of frozen soil, known as permafrost. There it stayed until a heatwave in the summer of 2016, when the permafrost thawed.

This exposed the reindeer corpse and released infectious anthrax into nearby water and soil, and then into the food supply. More than 2,000 reindeer grazing nearby became infected, which then led to the small number of human cases.

The fear is that this will not be an isolated case.

As the Earth warms, more permafrost will melt. Under normal circumstances, superficial permafrost layers about 50cm deep melt every summer. But now global warming is gradually exposing older permafrost layers.

Frozen permafrost soil is the perfect place for bacteria to remain alive for very long periods of time, perhaps as long as a million years. That means melting ice could potentially open a Pandora’s box of diseases.


Health officials in Hawaii have been warning residents not to touch snails or slugs with their bare hands because of an increase in cases of people coming into contact with a rare parasitic infection known as a rat lungworm. Experts are blaming its sudden spread across the United States on climate change and globalisation.

Snails are a known carrier of rat lungworm disease Photo: Getty

In the last two decades, there have only been two documented cases of rat lungworm infections in Hawaii. But in the past three months, six more cases have occurred in rapid succession. Other states where it has recently popped up include California, Alabama, Louisiana and Florida. According to the Atlantic, the first known case of the disease occurred in Taiwan in 1944 but in the past few years, it’s believed to have spread to the U.S. by way of rats in cargo ships.

Pretty much everything about this disease is nasty. Rat lungworm is a parasitic nematode (Angiostrongylus cantonensis) that begins its life as an infection in rat’s lungs, blood, and brains. From there, the rats defecate worm larvae that are spread to other creatures like snails, slugs and freshwater shrimp. Humans might eat one of these infected hosts or they might eat produce that has had the worm transferred to it by a host.

Next thing you know, your brain is being invaded and it doesn’t sound good at all. Once rat lungworm disease moves into the brain it can cause meningitis and its symptoms include tremors, pain, and inflammation. It is often fatal.

The Maui News reported on the recent cases this week and spoke with local residents about the spread of the invasive semi-slug on the island, and the infectious disease that it carries. Locals say that they have become increasingly paranoid about eating produce and they line their yards with slug bait. And for an area that thrives on tourism, paranoia about eating the local food can be an economic nightmare.

A local preschool teacher described her experience with parasitic meningitis that was a result of rat lungworm to the Honolulu Civil Beat:

The parasites are in the lining of my brain, moving around. Because I work with children I try to tell stories through word pictures. My visual graphic for what’s happening is that every once in a while somebody opens the top of my head, sets a hot iron inside my brain, then pushes the steam button.

I have a half dozen medicine bottles, several for pain because any movement of my head spikes my pain level to 12. I don’t see any improvement, just that every day is a different day, different pain.

The severity of the disease can vary wildly, there’s no known treatment, and it’s notoriously difficult to diagnose.

Cases of rat lungworm infections have been documented in over 30 countries and health officials are worried about its appearance in areas where previously the habitat was believed to be unsuitable. One recent surprise location was in Oklahoma. Scientists fear that this is just another consequence of climate change.

11 Responses to “Threat Multiplier: Climate Change Brings Deadly Health Surprises”

  1. If brain-eating amoebas infected Donald Trump, they’d starve to death.

    • Andy Lee Robinson Says:

      …and/or vomit…
      …or beg for a course of antibiotics…
      …or demand a new host…
      Lots of possibilities!

  2. redskylite Says:

    So many medical societies now reporting on the dangers and increase of health problems caused by both Climate Change and pollution. Yet Government’s are still continuing on with fossil exploitation in a gung ho fashion. completely oblivious to the medics. Has the result of winning votes given them the right to trample on the health of citizens?

    Not only is ill health caused by exhaust particles, rising temperatures, drought, flooding and melting, this 2015 report indicates higher CO2 concentrations affects thinking and perception. And the way the world is going lately I am afraid it is beginning to show. What are we setting future generations up for. ?

    “Exclusive: Elevated CO2 Levels Directly Affect Human Cognition, New Harvard Study Shows

    In a landmark public health finding, a new study from the Harvard School of Public Health finds that carbon dioxide (CO2) has a direct and negative impact on human cognition and decision-making. These impacts have been observed at CO2 levels that most Americans — and their children — are routinely exposed to today inside classrooms, offices, homes, planes, and cars.”

    • 1happywoman Says:


      When my screen refreshed after my post, I saw that you’d posted! Why do you think this issue doesn’t get more attention?

      • Andy Lee Robinson Says:

        The American health industry is concerned primarily with the health of the American health industry.
        More patients = more profit.
        Curing people reduces profits.

        The system is sick beyond parody.

  3. 1happywoman Says:

    I worry about the impact of rising CO2 levels on human cognition:

    “Despite uncertainty about when and at what concentration ambient carbon dioxide will peak, and the newness of research on its cognitive influence, Allen says the possibility that outdoor air might impair human decisionmaking can’t be ignored.

    • Andy Lee Robinson Says:

      Running your air through a bucket of lithium hydroxide will remove CO₂ and may help, then we can sell the resulting lithium carbonate to Elon, or the Republicans for medication.

      • 1happywoman Says:

        I think they need antipsychotics instead.

        I do have this dystopian vision that once the risk of cognitive decline goes mainstream, the rich will clamor to buy breathing masks from which they and their children can breathe air mixed to a pre-industrial level of CO2–yet another entrepreneurial opportunity arising out of climate change.

        • Andy Lee Robinson Says:

          A market for home scrubbers for A/C may well be a reality sooner than later.

          I used to think this was a joke:
          A study found 22% of Republicans take some form of antipsychotic medication.
          This is a shocking amount, because it means that 78% don’t.

  4. rabiddoomsayer Says:

    You forgot the spread of lime disease, the associated ticks are not being killed off with the milder winters in some places. Then there is the mosquito borne diseases. The known unknowns.

    The unknown unknowns are the scary issue here. What about Mollivirus sibericum, frozen for 30,000 years and still viable. Whole new families of viruses have been discovered (Pandoraviridae and Pithoviridae ).

  5. […] Threat Multiplier: Climate Change Brings Deadly Health Surprises […]

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