scholarly journals Experimental infection of emus ( Dromaiius novaehollandiae ) with avian influenza viruses of varying virulence: Clinical signs, virus shedding and serology

1999 ◽  
Vol 28 (1) ◽  
pp. 13-16 ◽  
Author(s):  
R. A. Heckert ◽  
M. McIsacc ◽  
M. Chan ◽  
E-M. Zhou
Keyword(s):  
Avian Influenza ◽  
Experimental Infection ◽  
Clinical Signs ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Virus Shedding

scholarly journals Distinct Pathogenesis of Hong Kong-Origin H5N1 Viruses in Mice Compared to That of Other Highly Pathogenic H5 Avian Influenza Viruses

2000 ◽  
Vol 74 (3) ◽  
pp. 1443-1450 ◽  
Author(s):  
Jody K. Dybing ◽  
Stacey Schultz-Cherry ◽  
David E. Swayne ◽  
David L. Suarez ◽  
Michael L. Perdue
Keyword(s):  
Influenza Virus ◽  
Hong Kong ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Transforming Growth Factor ◽  
Clinical Signs ◽  
Influenza Viruses ◽  
Rapid Weight Loss ◽  
Avian Influenza Viruses ◽  
Highly Pathogenic

ABSTRACT In 1997, an outbreak of virulent H5N1 avian influenza virus occurred in poultry in Hong Kong (HK) and was linked to a direct transmission to humans. The factors associated with transmission of avian influenza virus to mammals are not fully understood, and the potential risk of other highly virulent avian influenza A viruses infecting and causing disease in mammals is not known. In this study, two avian and one human HK-origin H5N1 virus along with four additional highly pathogenic H5 avian influenza viruses were analyzed for their pathogenicity in 6- to 8-week-old BALB/c mice. Both the avian and human HK H5 influenza virus isolates caused severe disease in mice, characterized by induced hypothermia, clinical signs, rapid weight loss, and 75 to 100% mortality by 6 to 8 days postinfection. Three of the non-HK-origin isolates caused no detectable clinical signs. One isolate, A/tk/England/91 (H5N1), induced measurable disease, and all but one of the animals recovered. Infections resulted in mild to severe lesions in both the upper and lower respiratory tracts. Most consistently, the viruses caused necrosis in respiratory epithelium of the nasal cavity, trachea, bronchi, and bronchioles with accompanying inflammation. The most severe and widespread lesions were observed in the lungs of HK avian influenza virus-infected mice, while no lesions or only mild lesions were evident with A/ck/Scotland/59 (H5N1) and A/ck/Queretaro/95 (H5N2). The A/ck/Italy/97 (H5N2) and the A/tk/England/91 (H5N1) viruses exhibited intermediate pathogenicity, producing mild to moderate respiratory tract lesions. In addition, infection by the different isolates could be further distinguished by the mouse immune response. The non-HK-origin isolates all induced production of increased levels of active transforming growth factor β following infection, while the HK-origin isolates did not.

scholarly journals Genetic and antigenic characteristics of H4 subtype avian influenza viruses in Korea and their pathogenicity in quails, domestic ducks and mice

2013 ◽  
Vol 94 (1) ◽  
pp. 30-39 ◽  
Author(s):  
Hyun-Mi Kang ◽  
Jun-Gu Choi ◽  
Kwang-Il Kim ◽  
Ha-Young Park ◽  
Choi-Kyu Park ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Clinical Signs ◽  
Significant Loss ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Post Inoculation ◽  
Avian Influenza Viruses ◽  
Domestic Ducks ◽  
Viral Shedding ◽  
Nationwide Surveillance

In Korea, a nationwide surveillance programme was implemented in 2003 to identify highly pathogenic avian influenza viruses (AIVs). AIVs belonging to one of the most common haemagglutinin subtypes, H4, were isolated from two domestic ducks and 52 wild birds between 2004 and 2010. These H4 AIVs could be further classified into three neuraminidase subtypes: H4N6 (94.4 %), H4N2 (3.7 %) and H4N3 (1.9 %). Phylogenetic analysis revealed that the H4 AIVs had a variety of genetic constellations, with at least nine different genotypes represented. The pathogenicity of these H4 viruses was assessed in quails, domestic ducks and mice. None of the H4 AIVs induced clinical signs in quails or domestic ducks. Viral shedding in quails was relatively high, and virus was recovered up to 5–7 days post-inoculation (p.i.) in oropharyngeal swabs, but the viruses replicated poorly in domestic ducks. Quails may act as an intermediate host in which AIVs are amplified and transmitted to other species. In mice, all of the AIVs were recovered efficiently at relatively high titres from the lungs up to 7 days p.i., demonstrating the potential for AIVs to infect mice directly without prior adaptation. None of the AIVs induced clinical signs nor was any lethal to infected mice. However, there was significant loss of body weight in mice infected with viruses of duck origin. It is suggested that the active surveillance of influenza viruses needs to be enhanced in domestic poultry as well as in wild birds, and that it should include assessment of pathogenicity in animal models.

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