Avian influenza virus H9N2 infections in farmed minks.

Chuanmei Zhang,Jian Qiao,Yang Xuan,Jianlin Wang,Haiyan Yang,Ke Wang,Guimei Li,Hu Shan

doi:10.1186/s12985-015-0411-4

Chuanmei Zhang, Jian Qiao + Show 6 more

Open Access

https://doi.org/10.1186/s12985-015-0411-4

Copy DOI

Abstract

BackgroundThe prevalence of avian H9N2 viruses throughout Asia, along with their demonstrated ability to infect mammals, puts them high on the list of influenza viruses with pandemic potential for humans. In this study, we investigated whether H9N2 viruses could infect farmed minks.MethodsFirst, we conducted a serological survey for avian influenza virus antibodies on a random sample of the field-trial population of farmed minks. Then we inoculated farmed minks with A/Chicken/Hebei/4/2008 H9N2 viruses and observed the potential pathogenicity of H9N2 virus and virus shedding in infected minks.ResultsH9 influenza antibodies could be detected in most farmed minks with a higher seropositivity, which indicated that farmed minks had the high prevalence of exposure to H9 viruses. After infection, the minks displayed the slight clinical signs including lethargy and initial weight loss. The infected lungs showed the mild diffuse pneumonia with thickened alveolar walls and inflammatory cellular infiltration. Influenza virus detection showed that viruses were detected in the allantoic fluids inoculated supernatant of lung tissues at 3 and 7 days post-infection (dpi), and found in the nasal swabs of H9N2-infected minks at 3–11 dpi, suggesting that H9N2 viruses replicated in the respiratory organ, were then shed outwards. HI antibody test showed that antibody levels began to rise at 7 dpi.ConclusionsOur data provided the serological and experimental evidences that strongly suggested farmed minks under the natural state were susceptible to H9N2 viral infection and might be the H9N2 virus carriers. It is imperative to strengthen the H9N2 viral monitoring in farmed minks and pay urgent attention to prevent and control new influenza viruses pandemic prevalence.

Highlights

Avian influenza virus (AIV) H9N2 have widely circulated in the world since its first detection from turkeys in 1966 [1]
The referral antigens and positive serum used in this study were H5N1 (RE-5, clade 2.3.4) and H5N1 (RE-7, clade 7.2) antigen, H7N9 (A/Pigeon/Shanghai/S1069/ 2013) antigen, H9N2 (A/Chicken/Shanghai/10/01) antigen and their corresponding positive serum purchased from Harbin Veterinary Research Institute, Harbin, China, usually as a avian standard antigen and positive serum to detecting specific antibodies against avian influenza virus in China
No antibodies were found against H7 subtype viruses (Table 2). This results showed that H5 and H9 subtype influenza virus were prevalent in farmed minks, no H7 subtype influenza virus existed in minks

Summary

Introduction

Avian influenza virus (AIV) H9N2 have widely circulated in the world since its first detection from turkeys in 1966 [1]. Recent studies have shown that H9N2 viruses are likely to contribute to the evolution of the H7N9 viruses that cause severe human respiratory infections in China. The high prevalence of avian H9N2 viruses in poultry, along with their demonstrated ability to infect mammals, puts them high on the list of a candidate virus for triggering a possible influenza pandemic potential for humans, and emphasizes the urgency to the study of their ecology and pathogenicity in different poultries and animals [6]. Ferrets as a model animal belonging to the family of Mustelidae, can become infected with avian influenza viruses including H9N2 viruses [8, 9]. The prevalence of avian H9N2 viruses throughout Asia, along with their demonstrated ability to infect mammals, puts them high on the list of influenza viruses with pandemic potential for humans. We investigated whether H9N2 viruses could infect farmed minks

Methods

Results

Conclusion