Did Climate Change Cause Lyme Disease?

Where did this Lyme epidemic come from? “Tick-checks” weren’t a thing when we were kids. Now, ticks not only swarm our conservation areas, but also our gardens and children’s playgrounds. More than 1/3 of them in our area are infected with Borrelia, the bacteria believed to cause Lyme Disease, and an unknown number are infected with Lyme “co-infections” such as Bartonella and Anaplasma. Our instinctual response to this threat is to kill tick populations as quickly as possible… But history, ecological principles, integrative medicine and current research all teach us that this approach doesn’t work. A more sophisticated approach, one that acknowledges underlying causes of this epidemic, is urgently required.

Lyme disease is not a new illness. Borrelia has been found in such ancient people as Otzi the Iceman who lived before 3100 BC, and in ticks fossilized in 15-million-year-old amber. The Lyme bacterium is millions of years older than humans and it’s lived relatively in harmony with humans until now. Lyme disease is well established in many countries and a good number of respected researchers blame climate change. “A sizable increase in the incidence of Lyme disease cases in endemic areas of the United States due to climate change is imminent”, write researchers associated with the renowned Mayo clinic[i].

Climate Change & Ticks

Our climate is steadily warming. Current models calculate a steady northward migration of black-legged ticks 46km each year, and similar expansion of white-footed mice that host ticks and infect them with Borrelia bacteria. Deforestation practices that contribute to warmer global climates further contribute to soaring tick populations by inhibiting natural mice predators such as foxes. And longer growing seasons in a warmer climate also mean more opportunity for ticks to grab blood meals from humans (i.e. transmitting more infection to humans). I could go on, but perhaps the point is made. These little armoured tanks can now thrive in regions that were prohibitively cold just a few years ago.

Can we blame incidence of Lyme disease on these exploding tick populations alone? Not likely. Even when tick populations are dramatically reduced with acaricides (pesticides for ticks) in residential areas, the incidence of Lyme disease does not decline.[ii] Humans have become a lot more sensitive to Lyme infection and this too, is associated with climate change.

Climate Change & Human Susceptibility to Disease

Like our environment, our bodies have become polluted with pesticides, heavy metals, and endocrine disruptors. Our immune system capacity is directly linked to burden with environmental contaminants and I hope to elaborate on this soon in a separate article. (A quick pubmed search on the topic brings up hundreds of relevant studies.) I spend a lot of time helping my patients improve their immune system function since this is often the defining variable that makes or breaks development of a chronic illness following a tick bite. The damage caused by environmental toxins to our immune system is one of the reasons why “Lyme-literate” practitioners call chronic Lyme disease an Environmentally-Acquired Illness.

Climate Change & Lyme Disease

When put all together, this means that climate change, as a product and inducer of environmental damage, is very possibly responsible for the Lyme disease epidemic now emerging. It does this by affecting both tick populations and our immune system function. Or put another way, damaged ecosystems, whether external to us or internal, are prime real estate for pathogens. Ticks thrive in damaged environments, just like bacteria and viruses thrive in damaged bodies (and our bodies are ecosystems – see past articles here on the human microbiome, for example).

Lyme disease teaches us that what happens to our environment, happens to us also. Treating the human body like an ecosystem, where everything is connected, is the first step to healing from chronic complex symptoms. Further, the actions we take to clean up our internal environment will have a corollary benefit on our external environment. Every person that makes lifestyle changes conducive to better health, whether biking to work, eating more local organic produce, or using glass storage containers instead of plastic – is making a significant impact on both environments. Please don’t underestimate the relevance of this.

We’re truly fortunate to live in a city that has officially proclaimed Climate Change an emergency. Promoting changes on a community level that slow progression of climate change and help us adapt to consequences of climate change, will have profound impacts on our health – far beyond the scope of this article! For more information about how climate change impacts Lyme Disease risk and our health in general, please see the additional resources below, or come chat with me about what you can do to make a difference.

Resources:

A useful article about tick-proofing your yard without spraying.

“Climate – A New Story” by Charles Eisenstein.

“Lyme – The First Epidemic of Climate Change” by Mary Beth Pfeiffer.

Lyme Prevention Guidelines (updated most years) by Dr. Sonya Nobbe ND

References:

[i] Dumic, Igor and Edson Severnini (2018). “Ticking Bomb”: The Impact of Climate Change on the Incidence of Lyme Disease. Canadian Journal of Infectious Diseases and Medical Microbiology. https://doi.org/10.1155/2018/5719081

[ii] Hinckley, F et al. (2016). Effectiveness of Residential Acaricides to Prevent Lyme and Other Tickborne Diseases in Humans. The Journal of infectious diseases. 214. 10.1093/infdis/jiv775.