Research and analysis

Influenza A (H1N1pdm09)

A rapid evidence summary identifying and assessing evidence related to the infectious and incubation period, and pre-symptomatic and asymptomatic transmission of Influenza A (H1N1pdm09).

• From: UK Health Security Agency
• Published: 8 May 2025

Documents

Infectious and incubation period, and pre-symptomatic and asymptomatic transmission of influenza A H1N1pdm09 subtype: a rapid evidence summary

Ref: GOV-18309

PDF, 639 KB, 50 pages

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Details

This rapid evidence review summarised available evidence on the infectious (timeframe in which an individual may transmit the infection to others) and incubation period (time between contracting an infection and symptom onset) as well as evidence on pre-symptomatic and asymptomatic transmission and location of exposure of influenza A subtype (H1N1pdm09).

This rapid evidence summary searched for research published between 1 January 2009 up to 31 July 2024 and included 26 studies. There were 4 cross-sectional, 18 prospective and 4 retrospective cohort studies.

Published 8 May 2025