ABSTRACT
In public health, independently by the technology use, contact tracing (CT) is the process of identifying people who may have met an infected person and subsequent collection of further information on these contacts. The differences between the potential methods of carrying out CT in 2003, during the SARS epidemic, and the current one SARS-CoV-2 are considerable. During the previous pandemic, current mobile technologies were not available (in particular the smartphone as we know it today). The role of the mobile technology—and therefore of the mobile Health (mHealth)—was and is basic during this pandemic for the digital contact tracing (DCT). The review, starting from the introduction of contact tracing performed manually, faced the potentialities and the technologies used for DCT based on dedicated APPs, interrogating on the state of development and on the aspects affecting the effectiveness of the DCT. From this review, various phases of the dissemination of medical knowledge around these Apps emerged. In a first phase, the novelty was high as well as the consequent difficulty on the part of epidemiology to set a concrete approach on them. Subsequently, scientific knowledge has spread, publications have increased and even the great IT giants have moved in the development of solutions. It was highlighted that hundreds of Apps have been/ proposed and/or are under development in the World according to different approaches in terms of the (I) technologies, (II) protocols (Bluetooth and Global Positioning System), (III) centralized governmental choice. The review in a first part extracted some important experiences in this Area captured during the first period;In a second part extracted some important outcomes from research of the next phases. The review ends pointing out the reasons for success/failure of the DCT and the lessons for the future for the epidemiologist. © Journal of Public Health and Emergency. All rights reserved.