Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010
Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countr...
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| Format: | Article |
| Language: | English |
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Colégio Brasileiro de Patologia Animal (CBPA)
2012-11-01
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| Series: | Pesquisa Veterinária Brasileira |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2012001100013&lng=en&tlng=en |
| _version_ | 1798045271094984704 |
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| author | Tatiane T.N. Watanabe Laura L. de Almeida Flademir Wouters Angelica T.B. Wouters Priscila Zlotowski David Driemeier |
| author_facet | Tatiane T.N. Watanabe Laura L. de Almeida Flademir Wouters Angelica T.B. Wouters Priscila Zlotowski David Driemeier |
| author_sort | Tatiane T.N. Watanabe |
| collection | DOAJ |
| description | Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management. |
| first_indexed | 2024-04-11T23:18:06Z |
| format | Article |
| id | doaj.art-de5c91f673264a19b7808f485278c4b7 |
| institution | Directory Open Access Journal |
| issn | 1678-5150 |
| language | English |
| last_indexed | 2024-04-11T23:18:06Z |
| publishDate | 2012-11-01 |
| publisher | Colégio Brasileiro de Patologia Animal (CBPA) |
| record_format | Article |
| series | Pesquisa Veterinária Brasileira |
| spelling | doaj.art-de5c91f673264a19b7808f485278c4b72022-12-22T03:57:33ZengColégio Brasileiro de Patologia Animal (CBPA)Pesquisa Veterinária Brasileira1678-51502012-11-0132111148115410.1590/S0100-736X2012001100013S0100-736X2012001100013Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010Tatiane T.N. Watanabe0Laura L. de Almeida1Flademir Wouters2Angelica T.B. Wouters3Priscila Zlotowski4David Driemeier5Universidade Federal do Rio Grande do SulUniversidade Federal do Rio Grande do SulUniversidade Federal do Rio Grande do SulUniversidade Federal do Rio Grande do SulUniversidade Federal do Rio Grande do SulUniversidade Federal do Rio Grande do SulSwine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2012001100013&lng=en&tlng=enSuínosvírus influenza Abronquiolite necróticahistopatologiaimuno-histoquímica |
| spellingShingle | Tatiane T.N. Watanabe Laura L. de Almeida Flademir Wouters Angelica T.B. Wouters Priscila Zlotowski David Driemeier Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 Pesquisa Veterinária Brasileira Suínos vírus influenza A bronquiolite necrótica histopatologia imuno-histoquímica |
| title | Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 |
| title_full | Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 |
| title_fullStr | Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 |
| title_full_unstemmed | Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 |
| title_short | Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010 |
| title_sort | histopathological and immunohistochemical findings of swine with spontaneous influenza a infection in brazil 2009 2010 |
| topic | Suínos vírus influenza A bronquiolite necrótica histopatologia imuno-histoquímica |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2012001100013&lng=en&tlng=en |
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