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Review
. 2024 Jun;24(6):e394-e404.
doi: 10.1016/S1473-3099(23)00619-9. Epub 2023 Dec 18.

The role of asymptomatic infections in influenza transmission: what do we really know

Martha P Montgomery  1 , Sinead E Morris  2 , Melissa A Rolfes  2 , Wanitchaya Kittikraisak  3 , Aaron M Samuels  2 , Matthew Biggerstaff  2 , William W Davis  3 , Carrie Reed  2 , Sonja J Olsen  2
Affiliations
Review

The role of asymptomatic infections in influenza transmission: what do we really know

Martha P Montgomery et al. Lancet Infect Dis. 2024 Jun.

Abstract

Before the COVID-19 pandemic, the role of asymptomatic influenza virus infections in influenza transmission was uncertain. However, the importance of asymptomatic infection with SARS-CoV-2 for onward transmission of COVID-19 has led experts to question whether the role of asymptomatic influenza virus infections in transmission had been underappreciated. We discuss the existing evidence on the frequency of asymptomatic influenza virus infections, the extent to which they contribute to infection transmission, and remaining knowledge gaps. We propose priority areas for further evaluation, study designs, and case definitions to address existing knowledge gaps.

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Conflict of interest statement

Declaration of interests We declare no competing interests.

References

    1. WHO. Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza. 2019. https://apps.who.int/iris/bitstream/handle/10665/329438/9789241516839-en... (accessed April 6, 2023).
    1. Eccles R Asymptomatic spread of flu is not proved. BMJ 2005; 331: 1145. - PMC - PubMed
    1. Patrozou E, Mermel LA. Does influenza transmission occur from asymptomatic infection or prior to symptom onset? Public Health Rep 2009; 124: 193–96. - PMC - PubMed
    1. Lau LL, Cowling BJ, Fang VJ, et al. Viral shedding and clinical illness in naturally acquired influenza virus infections. J Infect Dis 2010; 201: 1509–16. - PMC - PubMed
    1. Furukawa NW, Brooks JT, Sobel J. Evidence supporting transmission of severe acute respiratory syndrome coronavirus 2 while presymptomatic or asymptomatic. Emerg Infect Dis 2020; 26: e201595. - PMC - PubMed