AVIAN INFECTIOUS CORYZA: A REVIEW

Abstract

Avian infectious coryza is an acute respiratory disease of chickens caused by the bacterium Avibacterium paragallinarum and represents an important health and economic concern for poultry production. The disease is characterized by clinical signs such as nasal discharge, facial edema, conjunctivitis, reduced feed intake, and decreased egg production, which may result in significant production losses. This review aimed to describe the main aspects of the etiology, transmission, virulence, clinical manifestations, diagnosis, prevention, treatment, and traditional practices associated with avian infectious coryza. A narrative review of the scientific literature was conducted using SciELO, PubMed, Google Scholar, and the CAPES Periodicals Portal, complemented by specialized literature on avian diseases. The available literature indicates that the bacterium is maintained in poultry populations through infected and carrier birds, while disease expression may be influenced by management conditions, coinfections, and characteristics of circulating strains. Diagnosis should integrate clinical and epidemiological information with laboratory confirmation, particularly bacterial isolation and molecular methods such as polymerase chain reaction (PCR). Vaccination and biosecurity are important components of disease prevention, although antigenic differences among serovars may limit protection. Antimicrobial treatment may reduce clinical signs but does not necessarily eliminate carrier birds. Traditional practices involving medicinal plants have been reported in family-based poultry production; however, scientific evidence remains insufficient to establish their therapeutic efficacy specifically against avian infectious coryza. Overall, control of infectious coryza requires an integrated approach involving appropriate diagnosis, biosecurity, vaccination adapted to the epidemiological context, responsible antimicrobial use, and continuous epidemiological surveillance.