Dr Nigel: I had to look this one up! Lots of people have written that Hippocrates was the first person to describe the flu nearly 2,500 years ago. He was living in Greece at the time and wrote about an illness causing sore throat, aches and difficulty breathing (among other things). It is tempting to think that he was the first person to describe flu, but the problem is that these symptoms are common to many infections. It might have been flu, but it might also have been diphtheria, polio virus, dengue fever or lots of other infections.
Credit for the discovery of the flu virus is shared. Some experiments were done in France around 1918 by two men called, Nicolle and Le Bailly, who took lung secretions (basically snot!) from people with flu symptoms. First they put the snot into the nose and eyes of a monkey, which became sick, and then they injected it under the skin of a man, who also got flu symptoms (you can read an extract from the 1918 paper here: http://jama.ama-assn.org/content/71/26/2154.extract). This study was used to suggest that flu is caused by a virus that can be transmitted, but the study was limited (this means there are problems with the methods) and experiments like this wouldn’t be allowed today!
The main people involved were a vet in America called, Koen, who found flu-like illness in pigs in 1918, and a scientist called Richard Shope who proved that flu could be transmitted between pigs in the 1920’s. Curiously, UK scientists working with ferrets in 1933 found their animals became unwell after one of the researchers got flu. Eighty years later, ferrets are still used for experiments (instead of humans) to understand flu virus and vaccines.
You can read more about the discovery of flu here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1145139/
