1887
  1. Home
  2. Eurosurveillance
  3. Volume 30, Issue 31, 07/Aug/2025
  4. Article
Rapid communication Open Access
Like 0
Download

Abstract

In April 2025, a human seasonal reassortant influenza A(H1N2) virus with a 7:1 genetic constellation was detected in Sweden in a patient seeking primary care for influenza-like illness. The neuraminidase gene of this virus was from A(H3N2) and the remaining genes from A(H1N1)pdm09. The patient recovered. No additional cases have been detected through routine surveillance. This is so far the only identified A(H1N2) reassortant among three seasonal A(H1N1)pdm09 and A(H3N2) reassortants reported in GISAID from Europe during the 2024/25 season.

© Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Loading

Article metrics loading...

/content/10.2807/1560-7917.ES.2025.30.31.2500542
2025-08-07
2025-08-08
/content/10.2807/1560-7917.ES.2025.30.31.2500542
Loading
Loading full text...

Full text loading...

/deliver/fulltext/eurosurveillance/30/31/eurosurv-30-31-3.html?itemId=/content/10.2807/1560-7917.ES.2025.30.31.2500542&mimeType=html&fmt=ahah

References

  1. Wiman Å, Enkirch T, Carnahan A, Böttiger B, Hagey TS, Hagstam P, et al. Novel influenza A(H1N2) seasonal reassortant identified in a patient sample, Sweden, January 2019. Euro Surveill. 2019;24(9):1900124.  https://doi.org/10.2807/1560-7917.ES.2019.24.9.1900124  PMID: 30862332 
  2. Elbe S, Buckland-Merrett G. Data, disease and diplomacy: GISAID’s innovative contribution to global health. Glob Chall. 2017;1(1):33-46.  https://doi.org/10.1002/gch2.1018  PMID: 31565258 
  3. World Health Organization (WHO). Summary of neuraminidase (NA) amino acid substitutions assessed for their effects on inhibition by neuraminidase inhibitors (NAIs). Geneva: WHO. [Accessed 7 Aug 2025]. Available from: https://cdn.who.int/media/docs/default-source/influenza/laboratory---network/quality-assurance/human-nai-marker-table_for-publication_final_20240918.pdf?sfvrsn=c6d153ec_3
  4. Musharrafieh R, Ma C, Wang J. Profiling the in vitro drug-resistance mechanism of influenza A viruses towards the AM2-S31N proton channel blockers. Antiviral Res. 2018;153:10-22.  https://doi.org/10.1016/j.antiviral.2018.03.002  PMID: 29518414 
  5. World Health Organization (WHO). Summary of polymerase acidic protein (PA) amino acid substitutions assessed for their effects on PA inhibitor (PAI) baloxavir susceptibility. Genva: WHO. [Accessed 7 Aug 2025]. Available from: https://cdn.who.int/media/docs/default-source/influenza/laboratory---network/quality-assurance/antiviral-susceptibility-influenza/pa-marker-who-table_07-08-2024_updated_final-version.pdf?sfvrsn=5307d6fe_2&download=true
  6. Dyrdak R, Stamouli S, Ganeshappa Aralaguppe S, Ekman M, Safari H, Berg C, et al. A novel SARS-CoV-2 recombinant transmitted from a patient with an acute co-infection. Lancet Microbe. 2024;5(12):100998.  https://doi.org/10.1016/j.lanmic.2024.100998  PMID: 39366391 
  7. Nishikawa F, Sugiyama T. Direct isolation of H1N2 recombinant virus from a throat swab of a patient simultaneously infected with H1N1 and H3N2 influenza A viruses. J Clin Microbiol. 1983;18(2):425-7.  https://doi.org/10.1128/jcm.18.2.425-427.1983  PMID: 6619292 
  8. Mukherjee TR, Agrawal AS, Chakrabarti S, Chawla-Sarkar M. Full genomic analysis of an influenza A (H1N2) virus identified during 2009 pandemic in Eastern India: evidence of reassortment event between co-circulating A(H1N1)pdm09 and A/Brisbane/10/2007-like H3N2 strains. Virol J. 2012;9(1):233.  https://doi.org/10.1186/1743-422X-9-233  PMID: 23057530 
  9. Meijer A, Swaan CM, Voerknecht M, Jusic E, van den Brink S, Wijsman LA, et al. Case of seasonal reassortant A(H1N2) influenza virus infection, the Netherlands, March 2018. Euro Surveill. 2018;23(15):18-00160.  https://doi.org/10.2807/1560-7917.ES.2018.23.15.18-00160  PMID: 29667576 
  10. Trebbien R, Koch A, Nielsen L, Kur DK, Westerström P, Krause TG. A case of reassortant seasonal influenza A(H1N2) virus, Denmark, April 2019. Euro Surveill. 2019;24(27):1900406.  https://doi.org/10.2807/1560-7917.ES.2019.24.27.1900406  PMID: 31290388 
  11. Guo YJ, Xu XY, Cox NJ. Human influenza A (H1N2) viruses isolated from China. J Gen Virol. 1992;73(Pt 2):383-7.  https://doi.org/10.1099/0022-1317-73-2-383  PMID: 1538194 
  12. Li XS, Zhao CY, Gao HM, Zhang YQ, Ishida M, Kanegae Y, et al. Origin and evolutionary characteristics of antigenic reassortant influenza A (H1N2) viruses isolated from man in China. J Gen Virol. 1992;73(Pt 6):1329-37.  https://doi.org/10.1099/0022-1317-73-6-1329  PMID: 1607856 
  13. Xu X, Smith CB, Mungall BA, Lindstrom SE, Hall HE, Subbarao K, et al. Intercontinental circulation of human influenza A(H1N2) reassortant viruses during the 2001-2002 influenza season. J Infect Dis. 2002;186(10):1490-3.  https://doi.org/10.1086/344738  PMID: 12404167 
  14. Krammer F, Hermann E, Rasmussen AL. Highly pathogenic avian influenza H5N1: history, current situation, and outlook. J Virol. 2025;99(4):e0220924.  https://doi.org/10.1128/jvi.02209-24  PMID: 40145745 
  15. Lowen AC. Constraints, Drivers, and Implications of Influenza A Virus Reassortment. Annu Rev Virol. 2017;4(1):105-21.  https://doi.org/10.1146/annurev-virology-101416-041726  PMID: 28548881 
  16. Tamura K, Stecher G, Kumar S. MEGA11: Molecular Evolutionary Genetics Analysis Version 11. Mol Biol Evol. 2021;38(7):3022-7.  https://doi.org/10.1093/molbev/msab120  PMID: 33892491 
Novel influenza A(H1N2) seasonal reassortant virus identified in a patient, Sweden, April 2025
<p class="citation"> <span>Citation style for this article:</span> <span class="meta-value authors"> <a href="/search?value1=Dorina+Ujvari&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Ujvari Dorina</a>, <a href="/search?value1=Tove+Samuelsson+Hagey&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Samuelsson Hagey Tove</a>, <a href="/search?value1=AnnaSara+Carnahan&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Carnahan AnnaSara</a>, <a href="/search?value1=Neus+Latorre-Margalef&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Latorre-Margalef Neus</a></span>. Novel influenza A(H1N2) seasonal reassortant virus identified in a patient, Sweden, April 2025. <a href="/content/ecdc">Euro Surveill.</a> 2025;30(31):pii=2500542. <a href="https://doi.org/10.2807/1560-7917.ES.2025.30.31.2500542" title="doi link" target="_blank">https://doi.org/10.2807/1560-7917.ES.2025.30.31.2500542</a> <span class="ES_Article_citation"> <span class="generated">Received</span>: 23 Jul 2025;&nbsp;&nbsp; <span class="generated">Accepted</span>: 07 Aug 2025 </span> </p>
/content/10.2807/1560-7917.ES.2025.30.31.2500542
/content/10.2807/1560-7917.ES.2025.30.31.2500542
Loading

Data & Media loading...

Supplementary data

Submit comment
Close
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error