Outbreaks of Virulent Infectious Bursal Disease in Flocks of Battery Cage Brooding System of Commercial Chickens

Abstract

Clinical and pathological investigations were conducted on outbreaks of infectious bursal disease (IBD) in pullets under brooding using the battery cage system in a commercial poultry farm in Kaduna, Nigeria. Two consecutive outbreaks of IBD on the same farm were studied. The onset of the disease and morbidity and mortality rates were recorded. Postmortem examinations were conducted and gross lesions recorded. Tissues were collected and fixed in 10% buffered formalin and processed for histopathological examinations. In the first outbreak, 80 to 100% of the chicks were affected at the age of 4 to 5 weeks and mortality rate was 95.8% and lasted for 9 days. In the second outbreak, the mortality rate was 43.3% and it also lasted for 9 days. At the onset of the disease, the birds were also 4-week-old like in case 1. The disease was diagnosed based on clinical signs, pathology, and agar gel immunodiffusion test (AGID). Clinical signs, gross lesions, and histopathological findings were characteristic of virulent infectious bursal disease. After the first outbreak (case 1) the house was disinfected using polidine® (iodophor compound), V-ox® (inorganic peroxygen compounds), CID20® (quaternary ammonium chloride, aldehydes, and alcohol), terminator III® (phenols), and glutasan® (aldehyde and quaternary ammonium chloride). But they failed to eliminate the IBD virus from the poultry pen.

Evaluation of pathological changes of natural infectious bursal disease virus infection in the lymphoid organs of Black Harco pullets

“…The present study showed that the main gross lesions during the acute phase of virulent IBDV currently circulating in Nigeria in the primary and secondary lymphoid organs of pullet chicks are initial swelling and marked haemorrhages and acute inflammation characterized by hyperaemia followed by severe atrophy of the primary lymphoid organs. These early lesions in the bursae have been described by Okoye & Uzoukwu (1982); Oluwayelu et al (2002) and Aliyu et al (2016) during natural infections while Silva et al (2016) reported same in experimental infections. However, the capacity of the field virus to induce marked gross lesions in the thymus, spleen and caecal tonsils observed in the present study was not reported in those studies.…”

“…Though the virus strain involved in the present study was not determined, the exceptionally high morbidity (100%) and mortality (78%) recorded might suggest that the virus was a vvIBDV and reflects the economic importance of IBD in poultry production. The higher morbidity and mortality rates of commercial pullets was also reported by Aliyu et al (2016) in cases of outbreaks of IBD in 4 to 5-week-old vaccinated pullets, but the commercial birds cited in their study were from flocks that had some levels of maternal antibodies against IBDV, so the results could not be compared to the present study in unvaccinated pullet chicks. The respective period of greatest susceptibility and susceptibility of different breeds to clinical IBD has been reported to be 3 to 6 weeks of age, when the bursa of Fabricius is at its maximum development, with higher mortality rates in light than in heavier breeds (Okoye & Aba-Adulugba, 1998;OIE, 2016).…”

Efficacy of recombinant VAXXITEK HVT-IBDv vaccine against very virulent Infectious bursal disease virus (vvIBDv) challenge in layer chicks: A pilot study

“…At the time of challenge, residual MDA in four chicks from groups G3 and G4 respectively, may have still been high at 26 and 28 days of age and active immune responses may have been delayed or even absent at the time of challenge. Hence, the second vaccination with the intermediate vaccine did not provide sufficient protection for the chicks which was also observed in the field (Aliyu et al, 2016) and experimental conditions (Massi et al, 2008). However, in chicks that received the recombinant vector vaccine formulation (G1, G2) and in the control group unvaccinated and unchallenged (G5B), no clinical symptoms or mortality were recorded.…”

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

“…Infection with less virulent strains may not show remarkable clinical signs besides the chickens may have fibrotic or cystic bursa of Fabricius that might turn into atrophied prematurely (before six months of age). During postmortem diagnosis, the chickens showed hemorrhages in the pectoral or thigh muscles, dehydration, urate deposits within the kidneys, enlarged, edematous, hyperemic and or atrophic bursa of Fabricius (Aliyu et al, 2016;Khan et al, 2009). In chronic cases, presence of hemorrhage within the connection between gizzard and proventriculus is observed (Khan et al, 2017;Aliyu et al, 2016).…”

“…During postmortem diagnosis, the chickens showed hemorrhages in the pectoral or thigh muscles, dehydration, urate deposits within the kidneys, enlarged, edematous, hyperemic and or atrophic bursa of Fabricius (Aliyu et al, 2016;Khan et al, 2009). 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.…”