Certainly the spread of diseases caused by vectors (mainly mosquitoes, ticks and fleas) is influenced by the climate and its changes. However, the spread of vector-borne diseases also depends on a variety of other factors, such as geographical location, seasonal distribution, the type of soil tillage, but also political, administrative, economic, social and cultural factors (e.g. the level of ability/possibility of a population to access health care). Vectors and pathogens around the world have learned to adapt to daily and seasonal variations in climate and, in some cases, these variations have even created the most suitable conditions for their reproduction.

As much as it is true that the spread of infectious diseases depends on variations in climate, it is also true that the spread of infectious diseases depends on human habits, in fect, humans behaviours can influence exposure and thus “vector-human” contact.

It is a fact: high density population zones and high temperatures help the development of vector-borne diseases (e.g. malaria, ixodes scapularis, lyme); several studies have found that some particolar vector-borne diseases such as malaria, especially in geographical areas where temperatures are generally higher, tend to increase more easily than others. A typical example is the area of South America, where, in fact, malaria is very widespread and temperatures are high.

Other similar findings concern the geographical areas of North America and Europe: in the former, high temperatures favour the development of vector-borne diseases such asLyme (widespread in Canada) and Ixodes scapularis while, due to the typical hot and humid climate of Central and Northern Europe, the Chikungunya virus is the most widespread.

In the wake of what has just been said, further studies and investigations, including long-term ones, seem necessary to help quantify more precisely the relationships between vectors, their development and survival rates, climate variables and human habits. It is not necessary (and would be almost impossible) to produce statistical reference models considering the continuous variability of climate, but certainly increased vector surveillance and continuous monitoring of vector-borne diseases affecting humans are necessary to better address and counteract these problems.