Infectious diseases. Old diseases return and new agents emerge.
Peterson
E A
EA
Mandel
R M
RM
D003140:Communicable Disease Control; D003141:Communicable Diseases / Q000266:history / Q000382:microbiology* / Q000628:therapy; D049672:History, 19th Century; D049673:History, 20th Century; D049690:History, Ancient; D006801:Humans