Swollen-head syndrome in broiler chickens

Area of Science:

• Veterinary Medicine
• Virology
• Bacteriology

Background:

• Swollen-head syndrome (SHS) is a significant disease affecting broiler chickens.
• The condition is prevalent in Southern Africa, particularly in 4-6 week old birds.
• Previous research has not fully elucidated the causative agents of SHS.

Purpose of the Study:

• To identify the causative agents of Swollen-head syndrome in broiler chickens.
• To characterize the viral and bacterial components involved in the disease.
• To inform disease control strategies.

Main Methods:

• Clinical observations of affected broiler flocks.
• Isolation and identification of viral and bacterial pathogens.
• Serological testing to identify the coronavirus serotype.

Main Results:

• A mixed infection of a novel coronavirus serotype and Escherichia coli was identified as the cause of SHS.
• The identified coronavirus represents a previously unrecorded serotype.
• The disease was effectively controlled through a combination of an attenuated live-virus vaccine and antibacterial treatments.

Conclusions:

• Swollen-head syndrome in broiler chickens is etiologically linked to a novel coronavirus and Escherichia coli co-infection.
• The development of an attenuated live-virus vaccine is crucial for controlling this specific coronavirus strain.
• Antibacterial medication plays a role in managing the secondary bacterial component of the disease.