How Climate Change Increases the Spread of Infectious Diseases

In the last two decades, global carbon emissions have increased by at least 50%, leading to long-term changes in the environment and human health. These changes may increase the risk of contracting various infectious diseases.

[Carbon emission is the release of carbon dioxide and other greenhouse gases into the atmosphere through certain human activities].

A recent study conducted by researchers at John Hopkins University raised concerns that climate change will cause new heat-tolerant diseases to evolve that will render our natural body’s defence useless. The concerns raised suggest that the battle against climate change is also a battle against infectious diseases.

Photo credit: CPHD

Here are 3 ways climate change contributes to endemic spread of infectious diseases:

1. Seasonal variations promote the spread of infectious diseases:

One of the effects of climate change is unstable seasonal patterns, and these has affected the prevalence and transmission of many infectious diseases in no small way. As an illustration, some of the diseases that were primarily associated with tropical or sub-tropical areas (areas that are often warm and humid year-round) have begun to break into other regions of the world. This is because weather conditions are changing and it appears that these micro-organisms find the newer zones just as suitable for hosting, if not more than the originating zone.

E.g. Before 1970, dengue fever was a health challenge affecting only 9 countries, but now it is an endemic in more than 100 countries.

Also, when people move from place to place, say one country to another as a result of shelter displacements (which can result from climate change disasters like flooding), it not only burdens the infrastructural system of the destination country. There is the heightened risk of carrying illnesses into the country. A good example is "airport malaria."

2. Air pollutants may act as vehicle for viral transmission and weaken immunity:

A growing body of scientific evidence suggests that when air pollutants like black carbon, soot, nitrates etc. get into the bloodstream, they weaken the body's immune system and also contribute to the overall spread of viral diseases. The study provides evidence to show that long-term exposure to nitrogen dioxide (NO2) levels could be one of the most serious contributing factor to coronavirus (COVID-19) fatality/death rates. This is because NO2 exposure causes inflammatory in the lungs.

E.g. 78% of all deaths due to coronavirus in France, Germany,Italy and Spain as at 19th March 2020 occurred in large industrial areas where NO2 concentration is high and ranged between 177.1 and 293.7 μmol/m2 — according to the study.

More so, considering that China’s Wuhan province (largely industrial areas with high incidence of air pollution was a major zone where coronavirus and impact were significantly felt, it infers a lot.

3. Global warming could cause pathogenic mutations than humanity may not be able to endure:

As the earth continues to warm, changing the climate in many parts of the world, several virus and bacteria species will evolve in order to adapt to the new norm. Alas, our bodily defences may not be able to deal with all these new species.

What now?

Having established that climate change is correlated to the spread of infectious diseases, it is expedient for climate-related government parastatals such as meteorological agencies in African countries to monitor and forecast climate changes and its impact on endemics. This means that there is need to procure surveillance technologies for accurate forecasting and real-time surveillance. Doing so will go a long way to help the scientific community stay abreast of new pathogens and provide early diagnostics before it ever becomes a pandemic.

Finally, many developing nations do not have nor implement a climate change agenda despite the fact that it is an existential threat globally. There is need for governments to prioritise investment in programmes and schemes that address climate change and its impact on human health.


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Article credit: Michael Adesanya

Tags: #Health #ClimateChange #InfectiousDiseases

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