Spreading diseases in a warmer Arctic

Louis Dorémus

By GRID-Arendal

July 3^rd, 2017

Climate change is introducing new disease threats to northern regions due to changing temperatures and humidity levels. These allow pathogens or host species to survive the winters and expand their range poleward.

A project called “ Climate change effects on the epidemiology of infectious diseases and impacts on Northern societies” has identified potential climate-sensitive infectious diseases which may expand over northern regions as the climate changes rapidly.

From the 8 to the 12 of June, I attended ICASS IX, the International Congress on Arctic Social Sciences, a major event organised every three years by the International Arctic Social Sciences Association (IASSA). There, the issue of what we think of as southern diseases moving into the Arctic caught my attention for two main reasons. First, it is an aspect of climate change about which I previously knew little. Second, the connections between these diseases and many aspects of life and society make it important to know about this complex issue.

For example, higher temperatures facilitate outbreaks tularaemia, a disease that affects rodents, but also humans. In Sweden, the incidence of this tick or mosquito-borne disease increased 10-fold between 1984-1998 and 1999-2012. Similarly, in the Russian Komi Republic warmer temperatures have led to a 23-fold increase in tick-borne encephalitis in 20 years.

Thawing permafrost due to increasing temperatures creates other potential problems. Since the victims of past epidemics could not be buried deep in the frozen ground, the current thaw could set free the disease that killed them decades or centuries ago. This was the case with last year’s anthrax outbreak in the Yamal Peninsula in Russia which killed a boy, contaminated many other people, and killed more than 2000 reindeer which are essential to the region’s traditional herding economies. The last anthrax outbreak in the region was in 1941. As Peter Sköld, professor at Umea University’s Arctic Research Centre, explains, in addition to anthrax, thawing permafrost could relaunch other diseases such as influenza, or smallpox, which was completely eradicated in the 1970s. Outbreaks of such diseases could lead to major epidemics since immunity status in the population are very low.

Climate change has also indirect effects. As species move poleward, the patterns of disease transmission are modified. For example, a 2008 UN Russia report highlighted that in eastern Siberia, changing migration routes of wild animals combined with warmer winters may lead to the expansion of rabies infection.

Reindeer herding Dolgans, Khatanga region, Taimyr, Russia. Credit: GRID-Arendal/Peter Prokosch

For Arctic Indigenous Peoples, new infectious disease outbreaks pose a major threat. Chief Vyacheslav Shadrin, chairperson of the Yukagir Council of Elders spoke at one of conference sessions. Shadrin identified health as one of the main areas where climate change affects Indigenous People’s life in Yakutia (Russia). Camilla Risvoll and Grete K. Hovelsrud, two Norwegian researchers, and members of the infectious disease project, showed that the reduced access to pastures in mountain areas, partly due to climate change, pushes the Sámi reindeer herders of Northern Norway to find adaptive strategies by moving from mountains to coastal areas, or increasing feeding in yards. As the two authors highlighted, while providing solutions, these strategies also expose the herds to new diseases due to the different coastal climate – where ticks thrive more easily for instance – or to the proximity with other farm animals.

Shifting diseases ranges also occurs in a context where medical solutions are challenged by diseases’ potential antibiotic resistance. This might be of concern here, as many of the diseases identified as climate-sensitive by the project need to be treated with antibiotics.

Studying climate-sensitive infectious diseases requires cooperation between various fields of science and traditional knowledge. Climate sciences and medicine are key components, but finding solutions requires a dialogue between many non-medical fields, such as anthropology, conservation, and economics. Local and indigenous views and experiences are also key when it comes to environmental knowledge or adaptation, and should be included when working on solutions. Understanding the importance of transdisciplinary research projects and working towards connecting research fields is crucial in days of rapid climate change. It is challenging, since researchers from different fields traditionally work separately, and speak a ‘different language’. But it also provides opportunities to build bridges between disciplines, and understand better how the world we live in is interconnected.

Climate change impact on the spread of infectious diseases is not only an Arctic, but also a global concern. One important lesson I came away with was that while integrated research projects are crucial to understand the issue and its ramifications, awareness raising and outreach will help spread research findings and inform decision makers and the general public about these new threats and how to address them.