An important part, as much as 58%, of all known infectious diseases would have become more dangerous for humans due to global warming. This is what emerges from an American study published in ‘Nature climate change’ which demonstrated how out of 375 infectious diseases, 218 worsened due to climatic risks: in particular 160 were aggravated by global warming alone, 81 also by drought and 21 also by fires.
The impact of diseases such as Lyme, Dengue and even malaria was analyzed by measuring the climatic risks due to the emission of greenhouse gases, which causes droughts, fires, floods, heat waves or storms. The researchers concluded that there is a link between environmental change and the worsening of infectious diseases and that these weather events tended to amplify the impact of these diseases.
On the one hand, with global warming, these diseases are transmitted by multiple vectors – explain the authors of the study – on the other hand there is a great diversity of types of pathogens that now affect humans (viruses, bacteria, fungi, animals, etc.). The authors have thus identified more than 1,000 transmission routes, ‘such as mosquitoes, ticks or fleas’, indicates Yannick Simonin, virologist of Inserm, interviewed by ‘Le Monde’. With warming, some diseases can also be transmitted by water, such as gastroenteritis or some meningo-encephalitis.