EPIDEMIC louse-borne typhus has decimated armies and profoundly influenced campaigns over the centuries. Typhus claimed tens of thousands of Napoleon's Grand Army when he marched to Moscow. True to its traditions, typhus appeared in the first six months of the First World War, in the Balkan and Eastern areas, and subsequently in nearly all the countries and areas of Europe affected by the war, with the notable exceptions of France, Belgium, and Italy. Its scourges exceeded those of any other epidemic disease during the war, but British troops, although operating in areas where the disease was endemic, and in contact with infected allies and enemy, suffered little from typhus. Preventive measures were responsible for this freedom from the disease. Mortality was over 20 per cent in those small groups of British troops who did contract typhus. There was no typhus on Gallipoli, and there is no record of any cases of typhus among the troops of 1 NZEF, although there were outbreaks of the disease in Egypt and Palestine.

In the Second World War typhus again claimed thousands of victims on the Russian front, both Russian and German. With British troops their experience of the First World War was repeated—preventive measures again limited their cases to a small number. The full set of circumstances required for the outbreak or spread of an epidemic of typhus are lousiness, overcrowding, undernourishment, and filth. Where the care of troops and personal hygiene eliminates these conditions there is little danger of epidemic typhus, provided contacts with a poor local population are strictly limited.

Among New Zealand troops overseas in the Second World War there were only isolated cases of typhus. The greatest threat of an epidemic was to those prisoners of war in Lamsdorf camp, Germany, when some twenty cases developed among the 10,000 Allied prisoners there, but an epidemic was prevented by persuading the German authorities to allow the British medical officers to institute comprehensive control measures.