Melvin Sanicas

By Clement Meseko, Binod Kumar and Melvin Sanicas

The public health risk of influenza at the human-animal interface is dicey, due in part to continuous evolution of the virus. Influenza virus consist of 7 genera of which only influenza A is at present zoonotic, where subtypes H5, H7 and H9 of avian origin and subtype H1 and H3 of swine origin are important. The most devastating influenza pandemic in history was suspected to have emerged from avian reservoir and manifested in 1918. The first recognized direct human transmission of highly pathogenic avian influenza (HPAI) H5N1 occurred in 1997 in Hong Kong. Subsequently, many cases of varying severity have been described in people who were exposed to poultry. More recently in 2009, triple reassortant influenza A of swine origin (A/H1N1pdm09) caused the first pandemic of the twenty-first century and since 2013, H7N9 though initially benign in birds, caused fatal infection in humans who had contact with poultry. These public health threats from animal influenza virus are aggravated by increase co-mingling in shared human-animal environment. Therefore, the challenge of emerging zoonotic influenza viruses on human host immunity, efficacy of vaccines and antiviral resistance require continuous risk assessment of virological and clinical changes that have impact on control measures including advances in vaccines and chemotherapeutics.

Part of the book: Influenza