Systematic Veterinary Virology

TRANSMISSION

• PPR is not very contagious and transmission requires close contact between animals. Ocular, nasal, and oral secretions and faeces are the sources of virus. Infection occurs mainly through inhalation of aerosols produced by sneezing and coughing. Fomites such as bedding may also contribute to the onset of an outbreak. There is no known carrier state. The spread is not dependant on vectors. The appearance of clinical PPR may be associated with any of the following:
• History of recent movement or gathering together of sheep and/or goats of different ages 
• Introduction of recently purchased animals; contact in a closed/village flock with sheep and/or goats that had been sent to market but returned unsold; 
•  Change in weather such as the onset of the rainy season (hot and humid) or dry, cold periods
• Contact with trade or nomadic animals 
•  A change in husbandry (e.g. towards increased intensification) and trading practices