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

Abstract

This study examined the sequential pathological changes in the lymphoid organs (bursa of Fabricius, thymus, spleen and caecal tonsils) of 7-week-old Harco pullet chicks that showed severe clinical disease and lesions during a natural infection with a virulent infectious bursal disease virus. Clinical signs were sleepiness, droopy appearance, greenish-whitish diarrhoea, anorexia and prostration followed by death. Mortality rate was 78% within 3 days of the infection followed by recovery. Gross lesions were marked haemorrhages in the pectoral and thigh muscles, mucosa of the proventriculus and gizzard junction, and caecal tonsils. Bursa of Fabricius, thymus, spleen and kidneys were initially enlarged; however, bursa of Fabricius and thymus were later atrophic. Histologic lesions showed marked oedema, infiltration of heterophils, hyperaemia, and lymphoid depletion and hyperplastic corticomedullary layer in the bursa of Fabricius, lymphoid necrosis in thymus, spleen, and caecal tonsils. Lymphocytic depletion was marked in the bursa of Fabricius as early as day 1 of the infection, and in the spleen, thymus and caecal tonsils on day 2 of the infection. However, there were fibroplasias in the bursa of Fabricius and thymus but repopulation of lymphocytes in the spleen and caecal tonsils of birds sacrificed on day 6 of the infection. Confirmation of IBD was carried out using agar gel immunodiffusion test. The above observations showed that marked depletion of lymphocytes in the lymphoid organs correlated with marked clinical IBD while repopulation of lymphocytes in the spleen and caecal tonsils correlated with the recovery phase in pullet chicks. The description of the pathological changes in lymphoid organs caused by the IBDV currently circulating in Nigeria will be useful in assessing the time and recognition of early diagnostic features of the disease.

Current Symptoms and Pathological Changes of Bursa Fabricius from Commercial Farming Broilers Led to Infectious Bursal Disease

“…This research was similar with other research that enlarged and hemorrhage in the serosa of bursa Fabricius, slight hemorrhage on the plica bursa of Fabricius were showed (Akter et al, 2018b;Bharathi et al, 2021;Chowdhury et al, 1996;Kulsum et al, 2018;. The acute inflammatory swelling or enlargement of the bursa of Fabricius would occur in few days into the outbreak (Igwe et al, 2017). Bursa of Fabricius would be swollen (enlarged) with increased weight, because of congestion, exudation of fluid into the interfollicular tissues, accumulation of fluid in the necrotized lymphoid follicles forming cysts and presence of mucous, caseous or gelatinous exudate on mucosal folds lining the inside of the bursal lumen (Igwe et al, 2017;Wang et al, 2011).…”

“…The acute inflammatory swelling or enlargement of the bursa of Fabricius would occur in few days into the outbreak (Igwe et al, 2017). Bursa of Fabricius would be swollen (enlarged) with increased weight, because of congestion, exudation of fluid into the interfollicular tissues, accumulation of fluid in the necrotized lymphoid follicles forming cysts and presence of mucous, caseous or gelatinous exudate on mucosal folds lining the inside of the bursal lumen (Igwe et al, 2017;Wang et al, 2011).…”

Outbreaks of acute infectious bursal disease of chickens in Maiduguri, Nigeria (2008-2018): retrospective survey

“…The lesions were usually characterized by tissue necrosis, hemorrhage and acute in ammation. The acute in ammatory swelling or enlargement of the BF would occur in few days into the outbreak (Igwe et al, 2017) and was observed in majority (90.9%) of the outbreaks. The BF would be swollen (enlarged) with increased weight, because of congestion, exudation of uid into the interfollicular tissues, accumulation of uid in the necrotized lymphoid follicles forming cysts and presence of mucous, caseous or gelatinous exudate on mucosal folds lining the inside of the bursal lumen (Wang et al, 2011;Igwe et al, 2017).…”

“…The acute in ammatory swelling or enlargement of the BF would occur in few days into the outbreak (Igwe et al, 2017) and was observed in majority (90.9%) of the outbreaks. The BF would be swollen (enlarged) with increased weight, because of congestion, exudation of uid into the interfollicular tissues, accumulation of uid in the necrotized lymphoid follicles forming cysts and presence of mucous, caseous or gelatinous exudate on mucosal folds lining the inside of the bursal lumen (Wang et al, 2011;Igwe et al, 2017). A few of the outbreaks that were not associated with enlarged BF at postmortem might have been presented at the later stage of outbreak when the in ammation had receded and BF atrophy was setting in due to lymphocytic depletion from necrosis and apoptosis.…”

Pathomorphological changes in lymphoid tissue of bursa fabticius caused by different vaccine and field strains of gumboro disease virus detected in Ukraine

“…Тим не менш масові вакцинації призвели до деяких негативних наслідки. Так вищезгадані вакцинні штами, розмножуючись у тканинах бурси призводили до значного виснаження фолікулів, по аналогії з високовірулентними вірусами [3]. Вплив українських ізолятів вірусу на бурсу Фабріціуса до сьогодні лишається невстановленим.…”