HX29 ‘A soldier who brought the most important weapon to the battlefield: a microscope’

Abstract Lieutenant General Sir William Boog Leishman (1865–1926) was a Scottish pathologist and a pioneer in the study of tropical diseases, particularly leishmaniasis. His contributions to medicine were groundbreaking, and his work played a crucial role in the identification of the parasite Leishmania, the causative agent of leishmaniasis. Leishman was stationed in India during his military service, where he served as a medical officer. It was here that he made his landmark discovery in 1900, when he found ovoid bodies in spleens of soldiers who had died from a mysterious illness, later recognized as kala-azar (visceral leishmaniasis). This discovery helped establish Leishmania as the pathogen responsible for the disease. Leishman’s work was instrumental in the treatment of leishmaniasis, a condition that had long been a major health problem in tropical regions. He was among the first to use a microscope as a crucial tool for diagnosis and research, a practice that significantly advanced the understanding of parasitic diseases. His dedication to science and medicine earned him recognition not only in military circles but also in the medical field. Leishman’s work on kala-azar influenced subsequent research, paving the way for improved diagnostics and treatments for leishmaniasis. In addition to his discovery of Leishmania donovani, Leishman also contributed to the field of pathology through his research on malaria and other diseases. His work remains a lasting legacy in the study of tropical medicine, and he is remembered as a soldier who brought a microscope – the most important weapon – to the battlefield against infectious diseases.