Quarantine Through History.

This article on the historical evolution of quarantine has pre sented, by means of documented examples, the scientific prin ciples relevant to the effectiveness of quarantine, the logistic, economic, and political barriers through time to its correct implementation, and the health impact of local and large-scale quarantine. Quarantine is one of the oldest and most effective health measures elaborated by mankind, but it should not be consid ered the solution to every epidemiological problem. As clearly indicated by the AIDS epidemic, it has various limits with regard to ethical and legal issues, as well as to epidemiological and organizational problems. Overall, however, the basic conceptual and operational background of quarantine still has an epistemological and applicative value. The evidence-based current epidemiology and the evidence-based history of medicine show that the implementation of correct quarantine procedures is feasible and effective if tailored to geographical, social, and health conditions and when collaboration occurs among those concerned. The historical persistence of the term ‘quarantine,’ etymo logically indicating a 40-day period but now operatively defining variable time interventions for different communi cable diseases, is the best documentation of the continuing value of this health measure through the centuries.