Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus

Abstract

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.

Swine Influenza A Viruses and the Tangled Relationship with Humans

“…Argentina also reported distinct human seasonal 1B.2 viruses (Pereda et al 2011). In Brazil, H1N2 viruses with H1 HA and N2 NA genes of human seasonal origin and internal genes from H1N1pdm09 were similarly detected (Biondo et al 2014), followed by detection of an additional lineage of H1N2 reassortants with the H1N1pdm09 internal genes and human seasonal surface genes (Nelson et al 2015b). Chile reported two human seasonal lineage H1 viruses paired with N1 or N2 NAs that are each distinct from those found in other South American countries (Nelson et al 2015a).…”

A cross-sectional study of swine influenza in intensive and extensive farms in the northeastern region of the state of São Paulo, Brazil

“…The first report on the isolation of SIV from oral cavity of naturally infected swine occurred in the state of São Paulo only in 2006 (Mancini et al, 2006). Recent studies have identified the SIV in industrial and wild pig herds (Biondo et al, 2014;Schaefer et al, 2015). Thus, a study performed in 48 intensive pig farms in the southern region, found that around 30 % of them had 95 % of positive animals, resulting in a total animal level prevalence of 78.1 %, suggesting that the disease might be widespread in some Brazilian regions (Ciacci-Zanella et al, 2015).…”

Molecular survey of porcine teschovirus, porcine sapelovirus, and enterovirus G in captive wild boars (Sus scrofa scrofa) of Paraná state, Brazil

“…Many of the reported wild boar virus infections, such as HEV, PoR-VA, and porcine influenza A virus are known to infect other animal species and are considered important zoonotic diseases (Ruiz-Fons et al 2008, Meng et al 2009, Okadera et al 2013, Biondo et al 2014. Therefore, the potential risks of disease transmission among wild animals and livestock and/or the human population cannot be ignored.…”

“…Wild boars are susceptible to infections by viruses that also affect domestic pigs (Sus scrofa domesticus), such as porcine group A rotavirus (PoRVA), porcine circovirus type 2 (PCV2), hepatitis E virus (HEV), Aujeszky disease virus (ADV), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSF), torque teno sus virus (TTSuV), influenza A virus, and others (Ruiz-Fons et al 2008, Meng et al 2009, Okadera et al 2013, Biondo et al 2014. These animals are also susceptible to infections by PTV, PSV, and EV-G, which were described in asymptomatic wild boars in Hungary (Boros et al 2012a, Boros et al 2012b, Spain (Cano--Gómez et al 2013), and the Czech Republic (Prodělalová 2012).…”