Theory of contagion was first given by: (A) Paracelsus, (B) Fracastorius, (C) Vesalius, (D) Pare
Answer is B. Fracastorius, an Italian physician enunciated the 'theory of contagion'. He envisaged the transfer of infection minute invisible paicles and explained the cause of epidemics. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 5