ARS | Publication request: Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus

Submitted to: Veterinary Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 18, 2008
Publication Date: January 1, 2009
Citation: Kwon, Y., Lipatov, A.S., Swayne, D.E. 2009. Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus. Veterinary Pathology. 46:138-141.

Interpretive Summary: The H5N1 high pathogenicity avian influenza (HPAI) viruses have caused severe disease and death in poultry of Asia, Africa and the Middle East, and sporadic human infections and deaths. The guinea pig model was used to study H5N1 HPAI virus infections and disease for comparison with human infections. Individual guinea pigs were given two different H5N1 HPAI viruses in the nose or stomach. Mild depression was seen on 2 and 3 days post-inoculation (DPI) when exposed to a Vietnam H5N1 HPAI virus given via the nose. Virus given in the nose produced mild pneumonia. This localized lung disease was very similar to that in humans caused by season influenza viruses, but milder than lung disease reported for H5N1 human cases. Administration of the virus in the stomach did not produce infection or disease.

Technical Abstract: The H5N1 high pathogenicity avian influenza (HPAI) viruses have caused widespread disease of poultry in Asia, Africa and the Middle East, and sporadic human infections. The guinea pig model has been used to study human H3N2 and H1N1 influenza viruses, but knowledge is lacking on H5N1 HPAI virus infections. Guinea pigs were inoculated intranasally or intragastrically with A/Vietnam/1203/04 (VN/04) or A/Muscovy duck/Vietnam/209/06 (MDk/VN/06) viruses. Mild listlessness was seen on days 2 and 3 post-inoculation (DPI) in guinea pigs inoculated intranasally with VN/04 virus. On 5 DPI, the guinea pigs had bronchointerstitial pneumonia and virus was identified in bronchiolar epithelium and alveolar macrophages. Virus was isolated from the lungs but was lacking from other organs. Minimal lung lesions were seen in intranasal MDk/VN/06 group and virus infection was not demonstrated, but serological evidence of infection was observed. Intragastric exposure failed to produce infection or lesions with either virus. The localized respiratory disease in guinea pigs with H5N1 viruses was very similar to that of H3N2 and H1N1 influenza in humans, and less severe than reported for H5N1 human cases.