HUGO GREENHALGH AS World Health Organization scientists comb the Chinese city of Wuhan for the first cases of the coronavirus, a Canadian infectious disease expert believes he has found the source of another pandemic, HIV/AIDS, more than a century earlier. In a revised edition of his 2011 book "The Origin of AIDS", published last month, Jacques Pepin questions the "cut hunter" theory that the blood of a chimpanzee likely infected someone with the simian variant of HIV in Cameroon in the early 20th century. He now believes it is likely that the first instance of the zoonotic transmission of the…