Research and analysis

Influenza A (H3, H5, H7, H9, H10): asymptomatic and pre-symptomatic transmission

This rapid systematic review aimed to identify and summarise evidence of asymptomatic and pre-symptomatic transmission of influenza A (H3N8, H5N2, H5N5, H5N6, H5N8, H7N9, H9N2, H10N3 and H10N5).

• From: UK Health Security Agency
• Published: 9 December 2025

Documents

Asymptomatic and pre-symptomatic transmission of zoonotic influenza A: a rapid systematic review

Ref: Published December 2025

PDF, 368 KB, 25 pages

This file may not be suitable for users of assistive technology.

Request an accessible format.

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email publications@ukhsa.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Details

This rapid systematic review aimed to summarise evidence of asymptomatic and pre-symptomatic transmission of zoonotic influenza A (search up to 6 May 2025). No studies were identified for inclusion.

Published 9 December 2025