Immunohistochemistry: A Rapid and Specific Diagnostic Tool for Influenza Virus Infection in Pigs

Abstract

During the 2016 spring, a local outbreak of severe dyspnea, seromucous nasal secretion, anorexia and loss of productive performance was identified in an intensive pig farm in southern Chile. Samples of diseased animals were submitted to the Diagnostic Laboratory of the Faculty of Veterinary Medicine, in Chillan, Chile, for pathological and histopathological study. Macroscopically, lungs appeared to be congested, edematous and "non-collapsed", which could be related to lesions compatible with interstitial pneumonia. Microscopic lesions showed a variable thickening of the septa, epithelial necrosis of the airways, diffuse inflammatory infiltration surrounding bronchial and bronchiolar areas, inflammatory exudate in the alveolar spaces with activate alveolar macrophages and fibrin. All lesions were compatible with Swine Influenza Virus (SIV) infection, and we successfully confirmed through SIV nucleoprotein immuno histochemistry staining of said samples, by utilizing a rapid and specific first-line diagnostic method that allows a rapid decision-making tool to control the spread of the virus. Additionally, the presence of the virus was confirmed by a serological field study.

A Systematic Review Analyzing the Prevalence and Circulation of Influenza Viruses in Swine Population Worldwide

“…Rectal swab Nucleic acid extraction, reverse transcription, metagenomic sequencing IAV [300] Several studies used histological examinations e.g., immunohistochemistry or immunofluorescence to identify the IAV symptoms in lung or other internal organs of either dead or severely sick swine sacrificed for the investigations [130,189,315,318]. Immunohistochemistry provides a rapid and affordable diagnosis of the influenza virus disease using swine tissue samples [344]. One major benefit of immunohistochemistry is that it can be used in the retrospective analysis of the archived tissue samples [245].…”

Ubiquitous influenza A virus in Chilean swine before the H1N1pdm09 introduction

“…IHC was performed to detect the nucleoprotein of IAV following the protocol described by Casanova et al (2017). The full protocol is provided as Supplementary Information.…”

The Role of Pathology in the Diagnosis of Swine Respiratory Disease

“…Immunohistochemical detection of an antigen in tissue samples also denotes the distribution of pathogens in the organ/body and contributes to pathogenesis studies in both field and experimental trials [41][42][43]. IHC and ISH procedures to detect PRRSV, PCV2, and SIV [8,[44][45][46] were used to investigate their role in finishing pigs with respiratory disease [14,26,35,47], as well as in experimental reproduction of the disease and in coinfection models [48][49][50][51].…”