Ancient ideas of hygiene The ancient Greeks and Egyptians enjoyed relatively high standards of personal hygiene - they had been taught about the importance of cleanliness by their religious leaders. But it was the Romans who developed the first public toilets and enormous public baths. 19th-century developments Louis Pasteur and Joseph Lister's revolutionary ideas about using sterile instruments in clean hospitals were adopted in the 19th century. Before then, up to half of Lister's patients who had survived surgery were being killed by infections spread by germs. Infection and disease haven't been eliminated entirely in our hospitals yet, but they have been significantly reduced. Today and tomorrow Although hygiene in developing countries is being improved all the time, 36% of the world's population is still affected by poor hygiene. Furthermore, medical organisations will be challenged in the future by new infections and diseases; the world's population is so closely connected that potentially catastrophic epidemics will be transmitted around the globe in days.