Typhus, the subject of the fifth lecture in the series, was caused by a bacterium hosted by the human body louse, and has thus always been associated with dirty and overcrowded conditions and spread above all by armies marching across the countryside and living in filthy and unhygienic conditions. In 18th-century England it was known as ‘gaol fever’.
The ‘hyginenic revolution’ of the Victorian era reduced its incidence. Preventive measures taken on the Western Front reduced casualties, but it recurred during the Second World War, especially at Stalingrad and in Nazi concentration camps. The Nazis carried out numerous experiments on involuntary human subjects to try and develop preventive measures; in Nazi propaganda, the spread of typhus was attributed to the Jews, who were likened to bacilli or lice in order to make their mass murder at Auschwitz and elsewhere acceptable.