1902

Typhoid fever epidemic in Trier (Germany) leads to Koch’s finding that infections derived not from water or sewage but from healthy human “carriers.” Carrier hypothesis “one of Koch’s last significant bacteriological contributions” (Brock, 255-56). Ronald Ross receives second Nobel Prize in Medicine for work on role of mosquito in malaria transmission (Brock, 263). Publication of James Mackenzie’s The Study of the Pulse, Arterial, Venous and Hepatic (Mair, 179-183).