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Abstract

On 21 March 2026, avian influenza A(H9N2) virus was confirmed in Italy in a patient with miliary tuberculosis. The patient had recently travelled to West Africa. Following the detection of an unsubtypable influenza A virus, rapid molecular confirmation and full genome sequencing were performed. Phylogenetic analysis revealed that the virus belonged to subclade G5.5 and was closely related to African strains. Epidemiological investigations identified no additional cases, suggesting there was no evidence of onward transmission at the time of reporting.

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/content/10.2807/1560-7917.ES.2026.31.15.2600285
2026-04-16
2026-05-10
/content/10.2807/1560-7917.ES.2026.31.15.2600285
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References

  1. World Health Organization (WHO). Disease Outbreak News: Avian Influenza A(H9N2) - Ghana. Geneva: WHO; 20 Sep 2024. Available from: https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON534
  2. World Health Organization (WHO). Disease Outbreak News: Avian Influenza A(H9N2) - Italy. Geneva: WHO; 10 Apr 2026. Available from: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON597
  3. Regione Lombardia. Delibera n.63- (DL) Identificazione della rete di laboratori clinici per il supporto al panflu 2021-2023 e attivazione del sistema di sorveglianza delle sindromi respiratorie e influenzali in pronto soccorso e provvedimenti conseguenti alla dgr del 23 GENNAIO 20232 - N. XI/7811. [Regional Government Resolution No. 63 – (DL) Identification of the Network of Clinical Laboratories to Support PanFlu 2021-2023 and Activation of the Surveillance System for Respiratory and Influenza Syndromes in Emergency Departments, and Measures Consequent to Regional Government Resolution of 23 January 2023 – No. XI/7811]. Milan: Regione Lombardia; 23 Jan 2023. Italian. Available from: https://www.regione.lombardia.it/wps/portal/istituzionale/HP/istituzione/Giunta/sedute-delibere-giunta-regionale/DettaglioDelibere/delibera-63-legislatura-12
  4. Ministero della Salute. Circolare prot. num 2261 del 28 novembre 2025 Focolai di Influenza Aviaria da sottotipo H5N1: aggiornamento della situazione. [Newsletter 2261 of 28 November 2025 on avian influenza outbreaks of the H5N1 subtype: situation update]. Rome: Ministero della Salute; 28 Nov 2025. Italian. Available from: https://www.seremi.it/sites/default/files/Nota%20Ministero%20protocollo%202261%20dle%2028.11.2025.pdf
  5. Ministero della Salute. Circolare prot. num. 2627 del 29 gennaio 2025 – DGPRE: Focolai di Influenza Aviaria da sottotipo H5N1: aggiornamento della situazione epidemiologica e delle indicazioni di sanità pubblica. [Newsletter no. 2627 of 29 January 2025 – DGPRE: Outbreaks of avian influenza of the H5N1 subtype: update on the epidemiological situation and public health indications]. Rome: Ministero della Salute; 29 Jan 2025. Italian. Available from: https://www.fnovi.it/sites/default/files/2025_1_27_Circolare_aviaria.pdf
  6. European Centre for Disease Prevention and Control (ECDC). Risk assessment guidelines for diseases transmitted on aircraft (RAGIDA). ECDC: Stockholm; Dec 2010. Available from: https://www.ecdc.europa.eu/sites/default/files/media/en/publications/Publications/1012_GUI_RAGIDA_2.pdf
  7. Li H. New strategies to improve minimap2 alignment accuracy. Bioinformatics. 2021;37(23):4572-4.  https://doi.org/10.1093/bioinformatics/btab705  PMID: 34623391 
  8. Zhang J, Wang X, Chen Y, Ye H, Ding S, Zhang T, et al. Mutational antigenic landscape of prevailing H9N2 influenza virus hemagglutinin spectrum. Cell Rep. 2023;42(11):113409.  https://doi.org/10.1016/j.celrep.2023.113409  PMID: 37948179 
  9. Hatta M, Gao P, Halfmann P, Kawaoka Y. Molecular basis for high virulence of Hong Kong H5N1 influenza A viruses. Science. 2001;293(5536):1840-2.  https://doi.org/10.1126/science.1062882  PMID: 11546875 
  10. Suttie A, Deng YM, Greenhill AR, Dussart P, Horwood PF, Karlsson EA. Inventory of molecular markers affecting biological characteristics of avian influenza A viruses. Virus Genes. 2019;55(6):739-68.  https://doi.org/10.1007/s11262-019-01700-z  PMID: 31428925 
  11. Pinto RM, Bakshi S, Lytras S, Zakaria MK, Swingler S, Worrell JC, et al. BTN3A3 evasion promotes the zoonotic potential of influenza A viruses. Nature. 2023;619(7969):338-47.  https://doi.org/10.1038/s41586-023-06261-8  PMID: 37380775 
  12. Hurt AC, Holien JK, Parker MW, Barr IG. Oseltamivir resistance and the H274Y neuraminidase mutation in seasonal, pandemic and highly pathogenic influenza viruses. Drugs. 2009;69(18):2523-31.  https://doi.org/10.2165/11531450-000000000-00000  PMID: 19943705 
  13. Andreev K, Jones JC, Seiler P, Kandeil A, Webby RJ, Govorkova EA. Genotypic and phenotypic susceptibility of emerging avian influenza A viruses to neuraminidase and cap-dependent endonuclease inhibitors. Antiviral Res. 2024;229:105959.  https://doi.org/10.1016/j.antiviral.2024.105959  PMID: 38986873 
  14. World Health Organization (WHO). Summary of neuraminidase (NA) amino acid substitutions assessed for their effects on inhibition by NA inhibitors (NAIs) among avian influenza viruses of Group 1 (N1, N4, N5, N8 subtypes) and Group 2 (N2, N3, N6, N7, N9 subtypes) NAs. Geneva: WHO; 10 Oct 2025. Available from: https://cdn.who.int/media/docs/default-source/influenza/avwg/avian-nai-marker-who-table__10-10-2025.pdf?sfvrsn=bc0d1e9a_10
  15. World Health Organization (WHO). Summary of polymerase acidic protein (PA) amino acid substitutions assessed for their effects on PA inhibitor (PAI) baloxavir susceptibility. Geneva: WHO: 28 Nov 2025. Available from: https://www.who.int/teams/global-influenza-programme/laboratory-network/quality-assurance/antiviral-susceptibility-influenza/polymerase-acidic-protein-inhibitor
  16. Dong G, Peng C, Luo J, Wang C, Han L, Wu B, et al. Adamantane-resistant influenza a viruses in the world (1902-2013): frequency and distribution of M2 gene mutations. PLoS One. 2015;10(3):e0119115.  https://doi.org/10.1371/journal.pone.0119115  PMID: 25768797 
  17. European Centre for Disease Prevention and Control (ECDC). First human case of influenza A(H9N2) infection imported in the EU. Stockholm: ECDC; 25 March 2026. Available from: https://www.ecdc.europa.eu/en/news-events/first-human-case-influenza-ah9n2-infection-imported-eu
  18. Bogoch II, Andrews JR, Zachary KC, Hohmann EL. Diagnosis of influenza from lower respiratory tract sampling after negative upper respiratory tract sampling. Virulence. 2013;4(1):82-4.  https://doi.org/10.4161/viru.22466  PMID: 23135351 
  19. Centers for Disease Control and Prevention (CDC). CDC Laboratory Support for Influenza Surveillance Site. Atlanta: CDC. [Accessed: 30 Mar 2026]. Available from: https://www.cdc.gov/flu-pep-panel/clsis/index.html
  20. World Health Organization (WHO). WHO information for the molecular detection of influenza viruses: Real-time RT-PCR procedures for the detection of: A(H5N1) clade 1/2/3, A(H7N9), A(H9N2) viruses. Geneva: WHO; Aug 2024. Available from: https://cdn.who.int/media/docs/default-source/influenza/molecular-detention-of-influenza-viruses/protocols_influenza_virus_detection_2024.pdf?sfvrsn=df7d268a_8
  21. Panzarin V, Marciano S, Fortin A, Brian I, D’Amico V, Gobbo F, et al. Redesign and validation of a real-time RT-PCR to improve surveillance for avian influenza viruses of the H9 subtype. Viruses. 2022;14(6):1263.  https://doi.org/10.3390/v14061263  PMID: 35746734 
  22. Fusaro A, Pu J, Zhou Y, Lu L, Tassoni L, Lan Y, et al. Proposal for a global classification and nomenclature system for A/H9 influenza viruses. Emerg Infect Dis. 2024;30(8):1-13.  https://doi.org/10.3201/eid3008.231176  PMID: 39043566 
  23. Nguyen LT, Schmidt HA, von Haeseler A, Minh BQ. IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Mol Biol Evol. 2015;32(1):268-74.  https://doi.org/10.1093/molbev/msu300  PMID: 25371430 
Imported case of avian influenza A(H9N2) virus infection in a patient with miliary tuberculosis, Italy, March 2026
<p class="citation"> <span>Citation style for this article:</span> <span class="meta-value authors"> <a href="/search?value1=Elena+Pariani&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Pariani Elena</a>, <a href="/search?value1=Simona+Puzelli&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Puzelli Simona</a>, <a href="/search?value1=Gabriele+Del+Castillo&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Del Castillo Gabriele</a>, <a href="/search?value1=Greta+Romano&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Romano Greta</a>, <a href="/search?value1=Luca+Mezzadri&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Mezzadri Luca</a>, <a href="/search?value1=Cristina+Galli&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Galli Cristina</a>, <a href="/search?value1=Irene+Maria+Sciabica&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Sciabica Irene Maria</a>, <a href="/search?value1=Luigi+Vezzosi&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Vezzosi Luigi</a>, <a href="/search?value1=Francesca+Sabbatini&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Sabbatini Francesca</a>, <a href="/search?value1=Cristina+Paduraru&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Paduraru Cristina</a>, <a href="/search?value1=Irene+Mileto&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Mileto Irene</a>, <a href="/search?value1=Marcello+Tirani&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Tirani Marcello</a>, <a href="/search?value1=Anna+Teresa+Palamara&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Palamara Anna Teresa</a>, <a href="/search?value1=Paola+Stefanelli&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Stefanelli Paola</a>, <a href="/search?value1=Fausto+Baldanti&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Baldanti Fausto</a>, <a href="/search?value1=Danilo+Cereda&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Cereda Danilo</a>, <a href="/search?value1=Paolo+Bonfanti&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Bonfanti Paolo</a>, <a href="/search?value1=Collaborating+Centres%E2%80%99+Study+Group+on+Influenza&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Collaborating Centres’ Study Group on Influenza</a></span>. Imported case of avian influenza A(H9N2) virus infection in a patient with miliary tuberculosis, Italy, March 2026. <a href="/content/ecdc">Euro Surveill.</a> 2026;31(15):pii=2600285. <a href="https://doi.org/10.2807/1560-7917.ES.2026.31.15.2600285" title="doi link" target="_blank">https://doi.org/10.2807/1560-7917.ES.2026.31.15.2600285</a> <span class="ES_Article_citation"> <span class="generated">Received</span>: 31 Mar 2026;&nbsp;&nbsp; <span class="generated">Accepted</span>: 15 Apr 2026 </span> </p>
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