This is the story of the five Nobel Prizes for Physiology or Medicine that were awarded for the fight against malaria and some more that might be awarded in the future.
In medieval Italian, “mala aria” was the name for a disease that legends said had undermined the Roman Empire in earlier history. It weakened military forces in almost every area of the Mediterranean that the ancient Romans sought to control. A simple translation of the two words into modern English would be “bad air”. But this translation would be superficial, because in this case, “mala” meant not only bad — it also meant sinister, evil. Until the late 19th century, across a significant part of the world, people thought that daytime air was “good” and in some ways healthy, while nighttime air was “evil”. Therefore, every night, people tried to seal their houses hermetically, in as much as they could. They didn’t yet understand how insects transmit tropical diseases and that they are the real culprits for the perceived “malice” of the air at night when compared to the air in the daytime.
Indeed, among the tens of millions of species on Earth that remain alive today, the mosquito is the species that manages to kill the most humans every year, about 750,000 of them. It is followed by humans who, in one way or another, kill about 450,000 members of their own species each year. Snakes, which kill another 50,000 with their venom, are also an uncomfortable statistic. Dogs infected with rabies take care of about 25,000 human deaths a year, and Tsetse flies, which transmit sleeping sickness, contribute to about 10,000. They are followed by two species that seem quite benign. One looks like an unusual mix of a cockroach and a mantis, but in transmitting Chagas disease, it kills about ten thousand people each year, and they call it the Assassin bug. A seemingly benign snail that lives in freshwater, in turn, transmits schistosomiasis, by which another ten thousand human souls are taken. By comparison, crocodiles kill about 1,000 people a year, hippos around 500, lions and elephants 100 each, and wolves and sharks about 10 people a year.
Therefore, tourists in Africa should definitely stay away from elephants and lions, as any incident would lead to the largest relative impact on the annual statistics of the World Health Organisation and increase by as much as 2 per cent annually. But the animals you should really fear there are hippopotamuses and crocodiles. However, they are also a milder threat than the flies and dogs infected…