RESUMEN
Background: Inclusion body hepatitis (IBH) resulted in a substantial economic loss in Western India during 2019 to 2021. Aims: The study aimed to characterize fowl adenovirus (FAdV) from field outbreaks. Methods: The study was conducted on 290 liver samples from 66 poultry flocks. The samples were subjected to histopathology and molecular detection, followed by phylogenetic typing of the partial hexon gene of the virus. Results: Spiking mortality (14%) was recorded from day 21 to day 35 with peak mortality at the 28th day of age. The necropsy showed a pale and enlarged liver with hemorrhagic and yellowish necrotic foci, accumulation of straw-colored transudate in the pericardial sac which resulted in a flabby appearance of the heart, heart enlargement, and hemorrhages on the spleen, enlarged and congested kidneys. The virus inoculation resulted in stunting and poor feathering with hepatomegaly, hemorrhages and yellowish necrotic foci on the liver as well as greenish discoloration, and kidney swelling in SPF embryonated chicken eggs. Out of 29, 16 liver samples yielded 1219 bp amplicons specific to hexon gene fragments. The sequence and phylogenetic analysis identified 14 isolates as FAdV species E serotype 11 and two as species D serotype 8b. Conclusion: The results indicated that FAdV-8b and FAdV-11 strains are involved in disease outbreaks in western India.
RESUMEN
Background: Infectious bursal disease (IBD) caused substantial economic loss in central and western India during 2020 and 2021. Aims: The study was conducted to characterize IBD virus (IBDV) from field outbreaks. Methods: The study was conducted on 360 samples from 42 poultry flocks. The samples were subjected to histopathology and molecular detection, followed by phylogenetic typing of the partial VP2 gene. Results: The mortality ranged from 15.25 to 60.18%. The necropsy showed hemorrhages on thigh muscles, mottled spleen, swelling of kidneys and bursae with hemorrhages, and cheesy exudate. Histopathology revealed extensive necrosis and depletion of follicular lymphoid cells within the cortex and medulla, along with widespread hemorrhages, edema, and cystic cavities in the bursa. The field isolates showed cytopathic effects in the seventh passage. The cytopathic effects included swelling, rounding, granulation of cytoplasm around the nucleus, fragmentation of the infected cells, and detachment. The reverse transcription-polymerase chain reaction amplified 664 bp partial VP2 gene. The phylogenetic analysis identified 19 field isolates as very virulent IBDVs (vvIBDVs) and three as classical strains. Conclusion: The results indicated that different vvIBDV strains are involved in disease outbreaks in central and western India.