" Among the people visiting those temples, feeding handouts to those macaques, exposing themselves to SFV, are international tourists. Some carry away more than photos and memories. “Viruses have no locomotion,” according to the eminent virologist Stephen S. Morse, “yet many of them have traveled around the world.” They can’t run, they can’t walk, they can’t swim, they can’t crawl. They ride. "

― David Quammen , Spillover: Animal Infections and the Next Human Pandemic