Examining the constant reinvention of a disease by developing models of causality other than emergence and eradication is a timely and essential undertaking. Thus, the empirical examination of a major infectious disease - in this case syphilis over a period of more than 150 years - opens up an interdisciplinary and integrated sociobiological understanding of "epidemic growth and decay." It allows us to grasp the collective and individual prevention efforts developed during the 20th century, re-evaluated in the 21st century. It seeks to propose a model - if there is one - to explain neverending infectious diseases. A model that must integrate a sufficiently long time to grasp the phenomena of identity mutation of the disease. In this case, a long 20th century, which is also that of contemporary biomedicine, and which extends from Pasteurian microbiology to the current state of STIs.