These diseases are caused by viruses, bacteria and parasites, and affect more than one billion people, mainly in the tropics, where the most vulnerable developing world populations are concentrated.

But the map of tropical diseases like malaria, Chagas’ disease, sleeping sickness, leishmaniasis, schistosomiasis and dengue fever, is starting to change.

Tropical diseases transmitted by vectors like mosquitoes, flies, ticks or snails are directly affected by conditions in the ecosystems they inhabit, such as changes in humidity, water levels, temperature or rainfall, experts explain.

“Global warming is ‘tropicalising’ subtropical regions; rising temperatures could bring an explosion of parasite and insect vectors that are expanding into North America, the Southern Cone of South America, Australia and New Zealand,” Costa Nery said.

One sign of this, said the president of the SBMT, is the spread of leishmaniasis in Europe by travelling persons and dogs. He explained that the disease, which is endemic in southern Europe, could continue to spread northward if temperatures keep rising.

At the same time, climate variation in the tropics and its effects on the frequency of flooding and drought “could also modify the dynamic of the transmission of diseases,” with the emergence of vectors that alter the population’s immunity and resistance.

Via IPS covering the 18th International Congress on Tropical Medicine and Malaria, held Sept. 23-27 in Rio de Janeiro.