Swine Influenza A(H3N2) Virus Infection in Immunocompromised Man, Italy, 2014 - Volume 21, Number 7—July 2015 - Emerging Infectious Disease journal - CDC
Volume 21, Number 7—July 2015
Swine Influenza A(H3N2) Virus Infection in Immunocompromised Man, Italy, 2014
Pigs are considered the “mixing vessel” in which avian, human, and swine influenza genetic material can be exchanged and result in new influenza viruses (1). Zoonotic influenza A infections in humans caused by swine influenza viruses (SIVs) have been infrequently reported in Europe (1,2), even though at least 19% of occupationally exposed humans, such as pig farmers, slaughterers, and veterinarians, have SIV antibodies (3). However, because the infection is clinically mild in most cases, its frequency might be underdiagnosed in humans (4).
Three influenza A subtypes (H1N1, H1N2, and H3N2) circulate in swine herds in Italy (1). We report a European swine A(H3N2) influenza virus that occurred in an immunocompromised man in Italy in 2014.
Dr. Piralla is a clinical virologist at the Molecular Virology Unit of the Fondazione IRCCS Policlinico San Matteo in Pavia, Italy. His main research interests include molecular epidemiology of respiratory viruses, the study of virus evolution and interaction with the host, and design of next-generation sequencing protocols to study virus evolution and new pathogen discovery.
Additional members of the Influenza Study Group who contributed data: Alessia Griello, Marta Premoli, Franscesca Rovida, Bianca Mariani (SS Virologia Molecolare, SC Microbiologia e Virologia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy); Francesca Manola Adella (Dipartimento di Virologia, Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Brescia, Italy); Anna Maria Belloni (Azienda Sanitaria Locale); Maria Gramegna, Liliana Coppola, Alessandra Piatti, Laura Gemma Brenzoni (DG Sanità, Regione Lombardia, Milan, Italy); Mario Luini (Organizzazione Mondiale per la Salute degli Animali, Laboratorio di riferimento per l’Influenza Suina, Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Parma, Italy); Emanuela Foni and Laura Baioni (Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Parma, Italy)
We thank the Direzione Generale Sanità, Regione Lombardia; the physicians and veterinarians of the Azienda Sanitaria Locale involved in case management; and all the collaborators in the case definition. We thank Daniela Sartori for manuscript editing and Laurene Kelly for English revision.
This study was supported by grants from the Ministero della Salute, Fondazione IRCCS Policlinico San Matteo, Ricerca Corrente (grant no. 80622), Progetto Cariplo 2011-0517, Milan, Italy, and by a grant from the Ministero della Salute, IZSLER PRC2012002.
- Zell R, Scholtissek C, Ludwig S. Genetics, evolution, and the zoonotic capacity of European swine influenza viruses. Curr Top Microbiol Immunol.2013;370:29–55.
- Myers KP, Olsen CW, Gray GC. Cases of swine influenza in humans: a review of the literature. Clin Infect Dis. 2007;44:1084–8.
- Krumbholz A, Lange J, Dürrwald R, Walther M, Muller TH, Kuhnel D, Prevalence of antibodies to European porcine influenza viruses in humans living in high pig density areas of Germany. Med Microbiol Immunol (Berl). 2014;203:13–24.
- Gerloff NA, Kremer JR, Charpentier E, Sausy A, Olinger CM, Weicherding P, Swine influenza virus antibodies in humans, western Europe, 2009.Emerg Infect Dis. 2011;17:403–11.
- Piralla A, Baldanti F, Gerna G. Phylogenetic patterns of human respiratory picornavirus species, including the newly identified group C rhinoviruses, during a 1-year surveillance of a hospitalized patient population in Italy. J Clin Microbiol. 2011;49:373–6.
- World Health Organization. CDC protocol of realtime RTPCR for influenza A(H1N1). 2009 Oct 6 [cited 2009 Dec 15].http://www.who.int/csr/resources/publications/swineflu/CDCRealtimeRTPCR_SwineH1Assay-2009_20090430.pdf
- Hoffmann E, Stech J, Guan Y, Webster RG, Perez DR. Universal primer set for the full-length amplification of all influenza A viruses. Arch Virol.2001;146:2275–89.
- Lycett SJ, Baillie G, Coulter E, Bhatt S, Kellam P, McCauley JW, Estimating reassortment rates in co-circulating Eurasian swine influenza viruses. J Gen Virol. 2012;93:2326–36.
- Guindon S, Dufayard JF, Lefort V, Anisimova M, Hordijk W, Gascuel O. New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Syst Biol. 2010;59:307–21.
- Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol. 2011;28:2731–9.
- Tharakaraman K, Raman R, Stebbins NW, Viswanathan K, Sasisekharan V, Sasisekharan R. Antigenically intact hemagglutinin in circulating avian and swine influenza viruses and potential for H3N2 pandemic. Sci Rep. 2013;3:1822.
- World Organisation for Animal Health. Manual of diagnostic tests and vaccines for terrestrial animals. Chapter 2.08.08. Swine influenza [cited 2014 Jun 6]. http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.08.08_SWINE_INFLUENZA.pdf
- Castrucci MR, Donatelli I, Sidoli L, Barigazzi G, Kawaoka Y, Webster RG. Genetic reassortant between avian and human influenza a viruses in Italian pigs. Virology. 1993;193:503–6.
- Epperson S, Jhung M, Richards S, Quinlisk P, Ball L, Moll M, Human infections with influenza A(H3N2) variant virus in the United States, 2011–2012.Clin Infect Dis. 2013;57(Suppl 1):S4–11.
- Piralla A, Gozalo-Margüello M, Fiorina L, Rovida F, Muzzi A, Colombo AA, Different drug-resistant influenza A(H3N2) variants in two immunocompromised patients treated with oseltamivir during the 2011–2012 influenza season in Italy. J Clin Virol. 2013;58:132–7.
Suggested citation for this article: Piralla A, Moreno A, Orlandi ME, Percivalle E, Chiapponi C, Vezzoli F, et al. Swine influenza A(H3N2) virus infection in immunocompromised man, Italy, 2014. Emerg Infect Dis. 2015 Jul [date cited]. http://dx.doi.org/10.3201/eid2107.140981