The extreme weather conditions that are occurring are having an impact on pathogens as well as disease vectors or the way our bodies react to them.
Climate change: a definite impact on health
It is a fact accepted by the scientific community: climate change is affecting human pathogens. The idea of this study conducted by Camilo Mora was to quantify the impact. To do this, the team studied more than 77,000 scientific studies and publications in order to cross-check them with the authoritative databases of the GIDEON (Global Infectious Disease and Epidemiology Network) and the CDC (Center for Disease Control and Prevention). The result is that of the 375 diseases facing humanity, about 58% are aggravated by climate change. The study concludes that the proportion is too high for society to be able to quickly adapt and cope with the threat. Humankind could therefore face other epidemic waves in the future exacerbated by weather conditions that favor their development.
A study that tries to take all factors into account
The impact of heat on mortality waves in the elderly is well known. It is easy to realize the increase in mortality due to events such as floods or tornadoes. But it is true that we do not think about the impact of these on the various diseases that affect human beings.
If studies show that GHG emissions have an impact, the diversity of these is relatively large. These GHGs can increase drought, heat waves but at the same time increase the melting of glaciers, cause floods or sea level rise. Each change of parameter in the complex ecosystem that is our planet has repercussions that are sometimes difficult to measure. In the same way, the types of diseases (protozoa, bacteria, viruses, plants, animals…) and their modes of transmission (vectorial, airborne, by direct contact…) are as numerous and cross-checking these parameters increases the number of possibilities making the study of them longer and more tedious.
This study has therefore tried to compile all these data to try to bring out clear conclusions.
What future awaits us and how to face it?
The implications are complex because some factors can both aggravate and diminish certain conditions. For example, the snail host of schistosomiasis could be diminished by flooding in some cases, while in other cases flooding increased human exposure.
Similarly, heat seems to have contributed to a decrease in influenza epidemics, but certain extreme conditions (tornadoes, storms, floods, etc.) have increased the level of stress, decreasing the body’s immune capacity to respond to disease.
In addition, some effects are difficult to quantify, such as the increase in asthma due to temperatures or the difficulties in accessing health care induced by extreme weather events.
Whatever the case, we will have to adapt and adopt reflexes in order to protect our loved ones and the population because the future should continue to make living conditions more difficult.
All the data of the study as well as interactive tables are freely available on https://github.com/Camilo-Mora/Diseases