There are many infections in humans which originate from animals. Diseases which spread in this way are called zoonoses. Zika is one example and was first discovered in a monkey with a mild fever in the Zika forest in Uganda in the 1940s. Another is Middle Eastern Respiratory Syndrome or MERS – which originates in camels. A team from the United States has just mapped where they are found in the world and which animals are harbouring them. And, the map has thrown up a lot of surprises – with bats being behind far fewer zoonotic illnesses than previously thought. Dr Barbara Han, who is a disease ecologist at the Cary Institute of Ecosystem Studies, says half of carnivore species spread disease – far higher than previously thought and Europe is a “hotspot” for zoonoses.
There is a long history of maps being used to track the spread of disease – starting with John Snow. He worked out that cholera was a water-borne infection by mapping where people died in Victorian London – and traced it back to a dirty water pump.