The so-called "exotic" diseases in the tropics have long been noted both by travelers, explorers, etc., as well as by physicians. One obvious reason is that the hot climate present during all the year and the larger volume of rains directly affect the formation of breeding grounds, the larger number and variety of
natural reservoirs and animal diseases that can be transmitted to humans (
zoonosis), the largest number of possible insect
vectors of diseases. It is possible also that higher temperatures may favor the replication of pathogenic agents both inside and outside biological organisms. Socio-economic factors may be also in operation, since most of the poorest nations of the world are in the tropics. Tropical countries like Brazil, which have improved their socio-economic situation and invested in
hygiene,
public health and the combat of transmissible diseases have achieved dramatic results in relation to the elimination or decrease of many
endemic tropical diseases in their territory.
Climate change,
global warming caused by the
greenhouse effect, and the resulting increase in global temperatures, are possibly causing tropical diseases and vectors to spread to higher altitudes in mountainous regions, and to higher latitudes that were previously spared, such as the Southern United States, the Mediterranean area, etc. For example, in the Monteverde cloud forest of Costa Rica, global warming enabled Chytridiomycosis, a tropical disease, to flourish and thus force into decline amphibian populations of the Monteverde Harlequin frog. Here, global warming raised the heights of orographic cloud formation, and thus produced cloud cover that would facilitate optimum growth conditions for the implicated pathogen, B. dendrobatidis.
Role of human activities in the spread of tropical diseases Human activities, particularly those driving climate change, are significantly influencing the spread and geographical range of tropical diseases. The burning of fossil fuels, deforestation, industrial agriculture, and urbanization release large amounts of greenhouse gases into the atmosphere, raising global temperatures and altering weather patterns. These environmental changes, such as increased rainfall, higher temperatures, and more frequent extreme weather events, create more favorable conditions for disease vectors like mosquitoes, which transmit diseases such as malaria, dengue, and Zika. In many cases, this has expanded the reach of tropical diseases into regions that were previously unaffected, including higher altitudes and temperate zones. Additionally, human-driven habitat destruction, such as the clearing of forests and wetlands, disrupts natural reservoirs and increases human-wildlife contact, further elevating the risk of zoonotic diseases crossing into human populations. As climate change continues, these activities will likely exacerbate the public health burden, especially in low-income regions that are most vulnerable to both the impacts of climate change and the diseases it helps spread. ==Prevention and treatment==