Which species is primarily responsible for the zoonosis of Type A influenza?

The correct response to this question identifies waterfowl as the primary species responsible for the zoonosis of Type A influenza. Waterfowl, especially wild species such as ducks and geese, serve as a natural reservoir for many strains of avian influenza viruses, including Type A. These birds can carry the virus without exhibiting symptoms, allowing for the persistence and circulation of the virus in their populations.

In addition, when the influenza virus finds itself in new species, such as domestic birds, pigs, or humans, it has the potential to mutate and lead to the emergence of new viral strains, which can then cause outbreaks of disease in humans or other animals. This process often occurs through direct or indirect contact with infected waterfowl or their environments.

While pigs can act as a mixing vessel for different strains of the influenza virus—including both avian and human types—indicating their role in zoonotic transmission, they are not the primary reservoir species. Similarly, cows are not associated with the transmission of Type A influenza, which is predominantly linked to avian species.

Understanding the crucial role of waterfowl in the epidemiology of Type A influenza highlights the importance of monitoring these birds to prevent potential zoonotic spillovers and outbreaks in other vulnerable species, including