Clinical signs in affected birds may include decreased egg production and hatch-ability to the more common gastrointestinal or respiratory conditions. Clinical signs in affected people can be described as similar to a common flu that does not resolve in a short period of time. High temperatures and back pain may be noted. Newcastle disease is a serious and fatal viral disease of avian species. Affected birds may demonstrate neurological signs that progress to death.
Definitive diagnosis is through viral isolation of the organism.
The disease is quite contagious among birds, and has zoonotic potential that often may go unrecognized. Clinical signs in people most commonly involve a mild conjunctivitis, which is self-limiting. Affected birds may carry the disease for years, with intermittent organism shed. Clinical signs in avian species generally involve a significant weight loss in a poor-doing bird. Avian TB is considered a potential zoonotic disease especially in immunocompromised individuals.