A brief history of British military experiences with infectious and tropical diseases.

Infectious and tropical diseases have been a problem for British expeditionary forces ever since the Crusades. Outbreaks were especially common on Navy ships from the 16th to 18th centuries due to poor living conditions and travel to the tropics. However, since these occurred in small, isolated and controlled environments it meant that naval medical practitioners were able to keep detailed records and develop empirical approaches for their prevention. The first Royal Naval Hospitals were established in response to these diseases and Royal Navy doctors made valuable early contributions towards understanding them. Even larger outbreaks of infectious and tropical diseases occurred in the Army during the Napoleonic, Crimean and Boer Wars and throughout the colonial era, which strongly influenced the formation of the Army Medical Services including provision for teaching and research. The establishment of germ theory led to a golden era of discovery regarding these diseases and British Army doctors made numerous important contributions. Subsequent improvements in prevention, diagnosis and treatment reduced the mortality from infectious and tropical diseases during the World Wars, but they remained a significant problem in the non-European campaigns and also the numerous 'small wars' that followed. Even in the 21st century some of these diseases still cause outbreaks with significant morbidity and impact on deployments, but the military clinical and academic resources to deal with them are now much reduced. Preventive measures such as hygiene, sanitation, infection control, vaccination and chemoprophylaxis are invaluable, but history shows that these can become neglected over time and disrupted or overwhelmed during the early or most intense stages of military operations. This is why military specialists in infectious diseases, tropical medicine, sexual health, medical microbiology and communicable diseases control are still required