TYPHUS can upset the plans and frustrate the might of the most powerfully armed forces. During the War of 1914–18 it killed some 10,000 people in six months in Serbia; after the Russian Revolution it killed some three million Russians. It has been recorded that during the siege of Granada and in the Thirty Years' War and the campaigns of Napoleon, it killed more people than the military weapons then in use. A disease which frequently attacks starved and disorganized populations and flourishes in times of national disaster, it broke out in Spain in 1908 and again in 1941, and it is a constant problem in the South American States and elsewhere. It has to be watched constantly, and the pages of the Tropical Diseases Bulletin, the Bulletin of War Medicine, the Boletin de la Oficina Sanitaria Panamericana and other medical journals record the work that is being done on all its aspects.