Pathogenesis of Influenza A/H5N1 Virus Infection in Ferrets Differs between Intranasal and Intratracheal Routes of Inoculation

• Published in: The American journal of pathology Vol. 179; no. 1; pp. 30 - 36
• Main Authors: Bodewes, Rogier, Kreijtz, Joost H.C.M., van Amerongen, Geert, Fouchier, Ron A.M., Osterhaus, Albert D.M.E., Rimmelzwaan, Guus F., Kuiken, Thijs
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.07.2011; American Society for Investigative Pathology
• Subjects: Administration, Intranasal; Animals; Biological and medical sciences; Brain - virology; Brain Diseases - etiology; Brain Diseases - pathology; Disease Models, Animal; Dogs; Female; Ferrets; Human viral diseases; Immunoenzyme Techniques; Infectious diseases; Influenza A Virus, H5N1 Subtype - pathogenicity; Intubation, Intratracheal; Investigative techniques, diagnostic techniques (general aspects); Kidney - cytology; Kidney - virology; Lung Diseases - etiology; Lung Diseases - pathology; Medical sciences; Orthomyxoviridae Infections - pathology; Orthomyxoviridae Infections - virology; Pathology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Short Communication; Viral diseases; Viral diseases of the respiratory system and ent viral diseases; Virus Replication; Fissipedia; Carnivora; Pathogenesis; Orthomyxoviridae; Intranasal administration; Infection; Virus; Vertebrata; Anatomic pathology; Inoculation; Influenzavirus A; Mammalia; Influenza A virus; Viral disease; Ferret; Influenza A
• ISSN: 0002-9440; 1525-2191; 1525-2191
• DOI: 10.1016/j.ajpath.2011.03.026

Most patients infected with highly pathogenic avian influenza A/H5N1 virus develop severe pneumonia resulting in acute respiratory distress syndrome, with extrarespiratory disease as an uncommon complication. Intranasal inoculation of ferrets with influenza A/H5N1 virus causes lesions in both the respiratory tract and extrarespiratory organs (primarily brain). However, the route of spread to extrarespiratory organs and the relative contribution of extrarespiratory disease to pathogenicity are largely unknown. In the present study, we characterized lesions in the respiratory tract and central nervous system (CNS) of ferrets ( n = 8) inoculated intranasally with influenza virus A/Indonesia/5/2005 (H5N1). By 7 days after inoculation, only 3 of 8 ferrets had a mild or moderate bronchointerstitial pneumonia. In contrast, all 8 ferrets had moderate or severe CNS lesions, characterized by meningoencephalitis, choroiditis, and ependymitis, and centered on tissues adjoining the cerebrospinal fluid. These findings indicate that influenza A/H5N1 virus spread directly from nasal cavity to brain, and that CNS lesions contributed more than pulmonary lesions to the pathogenicity of influenza A/H5N1 virus infection in ferrets. In comparison, intratracheal inoculation of ferrets with the same virus reproducibly caused severe bronchointerstitial pneumonia. The method of virus inoculation requires careful consideration in the design of ferret experiments as a model for influenza A/H5N1 in humans.