Infectious Bursal Disease: Transmission, Pathogenesis, Pathology and Control - An Overview

SUMMARY

Infectious bursal disease (IBD) is an immunosuppressive disease of poultry causing great economic losses to the poultry industry. The disease is caused by infectious bursal disease virus (IBDV) and is characterised by bursal lesions, atrophy and immunosuppression. The causal virus targets B lymphocytes and is transmitted mainly by faecal-oral routes through ingestion of contaminated feed and water. Based on virus neutralisation, two serotypes of IBDV have been identified (serotypes 1 and 2), with serotype 1 considered to be virulent. Acute clinical outbreaks of classical IBDV are characterised by sudden onset, high morbidity, spiking and mortality curves with a rapid recovery time of about five to seven days, after clinical signs appear. Mortality rates vary within serotype 1 IBDV strains, ranging from no mortality by the variant strains, about 20% mortality with classical strains and over 50% mortality by very virulent strains. Post-mortem lesions are commonly, but not exclusively, reported in the bursa of Fabricius (BF) observed as haemorrhages, swelling and atrophy. The disease is diagnosed by isolation and characterisation, serology, including agar gel precipitation test (AGPT), enzyme linked immunosorbent assay (ELISA), and molecular techniques, such as reverse transcription polymerase chain reaction (RT-PCR). No effective treatment has been reported for IBD; it can be prevented by vaccination and implementation of strict biosecurity measures.

KEYWORDS:

• Infectious bursal disease
• immunosuppression
• bursa of Fabricius
• ELISA
• RT-PCR

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Ochuko Orakpoghenor

Ochuko Orakpoghenor is a researcher at Veterinary Pathology, Ahmadu Bello University, Zaria, Nigeria.

Sunday B. Oladele

Sunday B. Oladele is a professor of Veterinary Pathology, Ahmadu Bello University, Zaria, Nigeria.

Paul A. Abdu

Paul A. Abdu is a professor of Avian Medicine, Ahmadu Bello University, Zaria, Nigeria.