INFLUENZA - AN EMERGING DISEASE

Because all known influenza A subtypes exist in the aquatic bird reser voir, influenza is not an eradicable disease; prevention and control a re the only realistic goals. If people, pigs, and aquatic birds are th e principal variables associated with interspecies transfer of influen za virus and the emergence of new human pandemic strains, influenza su rveillance in these species is indicated. Live-bird markets housing a wide variety of avian species together (chickens, ducks, geese, pigeon , turkeys, pheasants, guinea fowl), occasionally with pigs, for sale d irectly to the public provide outstanding conditions for genetic mixin g and spreading of influenza viruses; therefore, these birds should be monitored for influenza viruses. Moreover, if pigs are the mixing ves sel for influenza viruses, surveillance in this population may also pr ovide an early warning system for humans.