New Climate, New Diseases, New Tools

For my final article in this series on the relationship between public health and climate change, I wanted to focus on a topic that I believe is simultaneously threatening and a source of optimism. Changing weather patterns over long periods of time are allowing certain diseases to thrive in environments where, previously, they would have been anomalies, and relatively ?easily traced back to their source of origin. Unfortunately, that will no longer be the case, especially for vector-borne diseases carried by species which are no able to range further afield. The good news is that investment in modern technology will allow public health agencies to absorb this threat, and cutting-edge AI technology may soon allow everyone to join in the surveillance of these diseases.

A full accounting of possible diseases and vectors which could evolve into broad public health threats is beyond the scope of this article, especially since some diseases will affect humans, others will affect livestock, etc. I’d like to focus on one infamous vector, and then (at the very end) comment on a weird case which has caused a stir. Let’s start with humanity’s deadliest vector throughout history: mosquitos.

Between malaria, dengue fever, and other diseases, mosquitos are probably the most dangerous animal on Earth. And yet, in the continuing theme of unequal distributions of health burdens, dengue fever had previously been confined to tropical and largely developing areas of the world. This is no longer the case, and incidence of dengue fever in Europe is steadily rising. California also recently confirmed a locally-acquired case of dengue fever, and since only 1 in 4 cases are symptomatic, the number of infected persons is likely higher. The spread of dengue is a direct result of the expanded range of the Aedes aegypti mosquito, which has thrived around the world after previously being confined to Africa. Dengue fever in the Western world is troubling not just because of the threat to human life, but also because of the strain on public health resources. The developing world relies upon dengue treatments produced elsewhere, and if European and American populations begin to require treatments en masse, the developing world will likely suffer.

Similar dynamics exist for malaria: an expanded habitat for disease-carrying mosquitos (warm, humid environs) carries with it the threat of disease. In 2023, the United States confirmed 8 cases which were acquired on US soil; the first such cases in 20 years.

The good news is that modern public health technology is well-equipped to cope with this oncoming disease burden. Modern public health infrastructure, through proper investment into local agencies, can integrate environmental data with health data and allow epidemiologists to quickly trace the source of an outbreak. In addition, AI tools deployed from mobile devices will soon play a role in the fight against vectors. These tools are already allowing citizens to identify individual animals within protected species as part of conservation efforts, such as protecting sea turtles in the Galapagos Islands. Soon, other tools drawing upon similar technology will be able to passively identify species of mosquitos, enhancing the surveillance efforts of public health agencies.

Although emerging diseases are a cause for alarm, the answer is straightforward: public health agencies at every level need modern data infrastructure to conduct timely surveillance and case management. The time to prepare is now, before the disease burden becomes a full-blown emergency. The threat is real, but the solution already exists; all we need is the foresight to act.

The weird case: a flesh-eating fungus originating in the American southwest is striking more and more people

It’s an attention-grabbing condition: flesh-eating fungus. Combine the typical macabre nature of the term ‘flesh-eating’ infections with the The Last of Us fascination with fungi, and we have an interesting case study. In this instance, ‘valley fever’ (caused by the fungus coccidioides) can wreak havoc on humans who are exposed to the spores. The fungus thrives in arid, dusty, windy environments, and has been known to inhabitants of the American southwest for a long time.

However, as cycles of drought become more intense, the rate of infections has quadrupled. Merely driving through an area with these spores can lead to infection, and as humans continue to push into undeveloped areas, it is likely that cases will continue to increase.

Although not a cause for population-level alarm, this is another example of how a shifting climate is incompatible with current societal behavior.

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