Comparative Antiviral Efficacy of Zanamivir and Amantadine Against Tunisian Isolate of Avian Influenza Virus (H9N2)

New emerging avian influenza A viruses pose a continued threat, not only to avian species but also to the humans. Avian influenza viruses increasingly crossing species barriers possibly with increased zoonotic potential. Due to rapid spread of influenza viruses, zoo animals and birds are at great risk. There are many species in zoos that are part of worldwide programme to save endangered species. Vaccination may protect birds kept in zoo against avian influenza as preventive and eradication programme along with culling and biosecurity. However, to eradicate influenza infection from valuable bird species in zoos, novel strategies are needed, including antiviral treatments. Antiviral treatments of infected birds kept in zoos are appropriate to prevent death of those birds that are part of genetics pool. The present study evaluated the anti-influenza efficacy of the potent neuraminidase inhibitor zanamivir and ion channel blockers amantadine in avian species using chickens. Zanamivir showed high antiviral efficacy than amantadine in the chicken model. Sequence analysis revealed mutation in matrix (M2) gene of virus for reduction in antiviral efficacy of amantadine. Antiinfluenza drug administration combined with active surveillance and vaccination strategies could be useful for control of AIV in precious captive birds.