A systematic review of contact tracing interventions for international arrivals by air, sea, or land

Introduction As part of the public health response, one role of health protection specialists is to identify contacts of people who have travelled whilst infectious, and provide advice or other public health actions. This paper aims to review the latest evidence for contact tracing of specific infectious diseases on incoming international travel by air, sea, or land. Twenty key gastrointestinal, respiratory, rash, and high consequence infectious diseases were included in this systematic review. Methods Electronic databases were systematically searched for studies published between 2008 and 2023, that focused on people arriving from international destinations with an infectious disease, and their contacts. Results were exported to Endnote; duplicates removed; eligible studies identified and critically appraised by two independent reviewers; and data extracted. Due to heterogeneity across studies, results were presented narratively. Results There was some evidence for contact tracing to reduce community transmission for international arrivals by aircrafts, but less rigorous evidence for those arriving by sea-vessels, and even less for ground crossings. Conclusions Informed by this systematic review, public health agencies should consider developing or reviewing their national disease-specific guidance, ensuring guidance for all key modes of international transport is included. Higher quality studies are required to inform the effectiveness of contact tracing for preventing further transmission related to international travel. Strategic efforts should continue to concentrate on improving the relationship between public health organisations and transport providers to facilitate timely public health actions.