This document provides a review of existing pandemic proximity detection methods, applications and other aspects of a pandemic contact tracing system. The similarities and differences of the various available or upcoming approaches are examined, particularly concerning but not limited to the degree of interoperability, security aspects, use of centralized or decentralized approach, use of particular proximity detection methods and technologies, support of different device platforms, epidemiological value and privacy aspects. The analysis also includes a grouping of various approaches into several similar types (e.g. centralized or decentralized system) and provides examples of use cases to which the approaches apply. The analysis is neutral in terms of technologies and use cases, however the focus is on cases involving proximity sensing and networking using mobile devices, and the applications and other technical enablers which can be installed on the devices. This document provides a basis for the analysis of suitable requirements for a standardised solution in Work Item D/E4P-003.