Ocean, desert rainfall and a parasitic disease: researchers connect patterns

Climate does more than shape the weather.

It can influence when and where infectious diseases emerge by changing how disease-carrying vectors and animal hosts survive and behave.

Scientists use weather data to anticipate some disease risks days or weeks ahead.

But forecasting how those risks will change across seasons and years remains difficult.

We asked Adrià San José Plana, a researcher in infectious disease modelling, and Xavier Rodó, a research professor and founding director of the Catalan Institute of Climate Sciences in Barcelona, about their recent research .

What’s known about the relationship between climate and diseases? Research has shown that vector-borne diseases – those transmitted by mosquitoes, ticks, sandflies and other arthropods – are particularly sensitive to climate .

These insects are ectotherms, meaning that they do not regulate their internal temperature in the same way humans do.

They are therefore strongly affected by environmental temperature.

Temperature influences their survival and longevity, how frequently they bite, and how quickly pathogens develop inside them before they can be transmitted .

Rainfall and humidity also dramatically affect their breeding and influence vector abundance .

Climate also affects the spread of zoonotic diseases, but often through a different mechanism .

This can happen when zoonotic host animals are forced to look for scarce food and move closer to human settlements.

What was the focus of your study? Our research focused on cutaneous leishmaniasis , a vector-borne disease transmitted by infected female sandflies .

There are around 1 million cases a year of cutaneous leishmaniasis in the world .