The fifth little horseman.
D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D007303:Insect Vectors / Q000382:microbiology*; D008887:Military Medicine / Q000266:history; D008003:Phthiraptera / Q000382:microbiology*; D012282:Rickettsia Infections / Q000266:history / Q000635:transmission*; D014438:Typhus, Epidemic Louse-Borne / Q000266:history / Q000635:transmission*