On the 18 March 1918 Thomas was admitted to a Brighton Hospital near Lewes. His medical records indicate he was admitted to hospital because of a ‘lung infection’. Remarkably, he spent 34 days in hospital recovering from his illness.
Thomas' admission to hospital remains a mystery. His illness may have been related to the chest wound he suffered from artillery fire September 2016. It is also possible that Thomas developed a chest infection from the first wave of the deadly influenza epidemic (the Spanish Flu). The epidemic was targeting mostly healthy young men, causing them to develop lung infections (pneumonia). Thomas’ military police work would have exposed him to overcrowded barracks, police cells and prisons; environments that increased the risk of contagion.
As the world remained in the grip of war, the 'Spanish Flu' entered a second, more deadly phase in the second half of 1918. During this period, millions of people had become infected with influenza. The allies and the Germanys placed a censorship on reporting mortality and morbidity rates to prevent their enemy from gaining a military advantage. Spain, which was a neutral country during WW1, did not support censorship of data and was transparent with information about its country's mortality rates. Accordingly, Spain's reporting of mortality rates gave the impression that the influenza pandemic only inflicted Spanish people.
Of course the flu pandemic did not just single out Spanish people. It is estimated that one third of the world’s population became infected by the flu and between 10-20% of infected people died. In Britain 250,000 people alone were killed by influenza. Statistically, the Spanish Flu killed more people than WW1 and is known as the most dangerous epidemic in recorded world history.
If Thomas' admission to hospital in early 1918 was caused by the first wave of the Spanish Flu, he was likely to have developed an immune response to the more serious strain of the flu, which developed during the second half of 1918. It is remarkable that Thomas survived both the Battle of Fromelles and the Spanish Flu.