Genetic characterization of influenza virus circulating in Brazilian pigs during 2009 and 2010 reveals a high prevalence of the pandemic H1N1 subtype
Article first published online: 28 DEC 2012
© 2012 John Wiley & Sons Ltd
Influenza and Other Respiratory Viruses
Volume 7, Issue 5, pages 783–790, September 2013
How to Cite
2012) Genetic characterization of influenza virus circulating in Brazilian pigs during 2009 and 2010 reveals a high prevalence of the pandemic H1N1 subtype. Influenza and Other Respiratory Viruses. 7(5), 783–790et al. (
- Issue published online: 21 AUG 2013
- Article first published online: 28 DEC 2012
- Manuscript Accepted: 23 NOV 2012
- Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ)
- Instituto Nacional de Ciência e Tecnologia (INCT-Pecuária)
- Pró-Reitoria de Pesquisa da UFMG
- Genetic characterization;
- influenza A virus;
Influenza A viruses circulating in pigs in Brazil are still not characterized, and only limited data are available about swine influenza epidemiology in the country. Therefore, we characterized the hemagglutinin (HA) and neuraminidase (NA) genes of influenza viruses isolated from Brazilian pigs. We also evaluated one case of probable swine-to-human transmission.
Twenty influenza viruses isolated from pigs during 2009–2010 in five Brazilian states (Minas Gerais, Sao Paulo, Parana, Rio Grande do Sul, and Mato Grosso) were used. One human isolate, from a technician who became ill after visiting a swineherd going through a respiratory disease outbreak, was also used in the study. Phylogenetic analysis for the HA and NA genes and hemagglutinin amino acid sequence alignment were performed.
All isolates clustered with pandemic H1N1 2009 (pH1N1) viruses and appeared to have a common ancestor. Genetic diversity was higher in the HA than in the NA gene, and the amino acid substitution S203T in one of HA's antigenic sites was found in most of the samples. The human isolate was more related to swine isolates from the same herd visited by the technician than to other human isolates, suggesting swine-to-human transmission.
Our results show that pH1N1 was disseminated and the predominant subtype in Brazilian pigs in 2009–2010.