<p>Infectious bursal disease virus in chickens: prevalence, impact, and management strategies</p>

Abstract

Infectious bursal disease (IBD), also known as Gumboro disease, is a highly contagious, immunosuppressive disease of young chickens. Although first observed about 60 years ago, to date, the disease is responsible for major economic losses in the poultry industry worldwide. IBD virus (IBDV), a double-stranded RNA virus, exists as two serotypes with only serotype 1 causing the disease in young chickens. The virus infects the bursa of Fabricius of particularly the actively dividing and differentiating lymphocytes of the B-cells lineage of immature chickens, resulting in morbidity, mortality, and immunosuppression. Immunosuppression enhances the susceptibility of chickens to other infections and interferes with vaccination against other diseases. Immunization is the most important measure to control IBD; however, rampant usage of live vaccines has resulted in the evolution of new strains. Although the immunosuppression caused by IBDV is more directed toward the B lymphocytes, the protective immunity in birds depends on inducement of both humoral and cell-mediated immune responses. The interference with the inactivated vaccine induced maternally derived antibodies in young chicks has become a hurdle in controlling the disease, thus necessitating the development of newer vaccines with improved efficacy. The present review illustrates the overall dynamics of the virus and the disease, and the recent developments in the field of virus diagnosis and vaccine research.

Sequence-based comparison of field and vaccine strains of infectious bursal disease virus in Ethiopia reveals an amino acid mismatch in the immunodominant VP2 protein

“…This is further supported by the fact that the first confirmed case of IBD was reported on a commercial farm where a live attenuated vaccine imported from the Netherlands had been used. Evidence from the literature suggests that vvIBDV strain DV86, which was first detected in the Netherlands in 1986, spread from there to various parts of the world [5].…”

Efficacy of two diagnostic tests for the detection of infectious bursal disease viruses in chicken from different types of bursal samples

“…Previous report suggested that for viral replication, bursa of Fabricious is the vital target organ. In acute case, bursa of Fabricious is haemorrhagic, oedematous, turgid and within 7 to 10 days turns in atrophic (Dey et al, 2019). These differentiations in clinical signs depend on the subsistence of maternal immunity, virulence of causative agent and bird's age (El-Samadony et al, 2019;Rauw et al, 2007;Hassan, 2004).…”

“…These differentiations in clinical signs depend on the subsistence of maternal immunity, virulence of causative agent and bird's age (El-Samadony et al, 2019;Rauw et al, 2007;Hassan, 2004). In the bursa of Fabricious, the stage of B cell differentiation keeps a vital role for viral replication as the stem cell (Dey et al, 2019). Our study (95) observes that, there might be the possible difference among the bursal samples for pathogenesis of IBD were irreversible bursal follicle damage and IgM-bearing B lymphocytes and others cell damage (Rodriguez-Chavez et al, 2002), those were more severe in haemorrhagic bursa compared to oedematous and atrophied bursa which increased the sensitivity in haemorrhagic bursa compared to oedematous and atrophied bursa for IBDV.…”

“…In chronic cases, presence of hemorrhage within the connection between gizzard and proventriculus is observed (Khan et al, 2017;Aliyu et al, 2016). The virus generally infected the lymphoid tissue especially the bursa (Dey et al, 2019;Wang et al, 2011;Van den Berg et al, 2000) and thus others immune organs like as spleen, bone marrow, thymus are also involved. Several diagnostic methods are used for the identification of IBDV through various levels of specificity and sensitivity (Daodu et al, 2018;Oluwayelu et al, 2014;Okwor et al, 2011;Hussain et al, 2003;Nachimuthu et al, 1995;Aliev et al, 1990;Allan et al, 1984).…”

“…RT-PCR is the method which helps for precise and early diagnosis of viruses from field samples (Hasan et al, 2010). Among these diagnostic methods, in this study we chose ODIT and RT-PCR as ODIT is simplest of all, inexpensive and has the ability for detecting specific antibodies (Dey et al, 2019;Hornbeck, 2017;Ouchterlony, 1948;Ouchterlony and Nilsson, 1986) and RT-PCR is specific, sensitive, speedy, reliable and accurate techniques for detection of IBD viruses (Hasan et al, 2010).…”