Infectious Coryza (IC) is a highly contagious, acute respiratory disease of chickens, that is characterized by nasal discharge, facial swelling and anorexia. The causative agent of infectious coryza is Avibacterium paragallinarum. Chronically ill or healthy carrier birds are the reservoir of infection. While chickens of all ages are susceptible, the susceptibility increases with age.
IC is global and causes economic losses due to increased mortality, decreased egg production (typically, 10-40%; particularly on multi-age farms).
Chickens that have recovered from the disease or chronically sick chickens are carriers of the bacterium and are the main source of the infection. “All-in/all-out” farm programs and vaccines are the best method of control. Suitable vaccines should be matched with reported serovars as there is no guaranteed cross protection between different serovars.