Explores the events surrounding the discovery of the etio-pathogenic agent of the Oroya Fever, also known as Peruvian Verruga or Carrión's disease by Dr. Alberto Leonardo Barton. Graciela S. Alarcón and Renato D. Alarcón recount Barton's persistent work against scepticism, obstacles, and limitations imposed by members of Peru's medical elites of the time.