The virus is in nasal secretions 3 days after infection. There is no carrier state. In endemic areas, PPRV is always present, but the incidence of the disease is cyclic. After an outbreak, antibody levels are high, and the virus dies out in many herds. A susceptible population develops, and when PPRV is reintroduced, an epizootic with almost 100-percent mortality may occur.
Goats are usually more susceptible than sheep.
The severity of disease and associated mortality are increased in animals in a poor state of nutrition or suffering from concurrent parasitic or bacterial disease.