Abstract:
Marek's Disease Virus (MDV) is highly contagious, cell-associated, oncogenic herpesvirus
that causes lymphoproliferative and neuropathic illness in domestic bird. In Ethiopia, it
has been reported to be a potential threat to both local and exotic breeds in the backyard
and commercial farming systems. A cross-sectional observational study was conducted to
isolate and molecular detection of MDV from clinically sick chicken circulating in Oromia
special zone around finfine from September 2021 to April 2022. The study employed
outbreak investigation of poultry farms in these selected areas (Sululta, Chancho, Lega Dadi, Leg-aTafo, Sandaf, Dukam, Akaki, Sebeta, Burayu, And Holota). In total, 47 poultry
farms were seen in 10 different towns, and 10 outbreaks were identified in six of those
towns. A total of 31 chickens were sampled, and it was discovered that 24 of them (or
77.42%) acquired paralysis of the leg, while 26 (or 83.87%) also developed chicken rough
and increased feather follicles, and all of the sick birds were exhibited additional complex
clinical indications. Based on internal organ lesions from a total of 31sample (13 feather
follicles, 10 spleens, and 8 livers) were inoculated on to confluent monolayer of CEF cells
and incubated at 37°C in a humid incubator containing 5% CO2. After 3-7 days
development of characteristic CPE for MDV were developed in 18(58.07%) sample (9
feather follicle (69.23%), 6 spleen (60%) and 3 liver 37.5%). All the isolates that were
grown and developed CPEs show visible small plaques on CEF cell cultures starting from
the 3rd day of the 3rd blind passage. From a total of 31 extracted DNA 25(80.65) of pooled
sample tissue, PCR results revealed the presence of a 318 bp fragment of the MDV ICP4
gene. Thus, from 10 Spleen, 8 (or 80% of them), 13 Feather follicles11 (or 84.62%), and 8
Liver (or 75% of them) were confirmed as the MDV's causes. Therefore, from 10 Spleen, 8
(80%), 13 Feather follicles11 (84.62%), and 8 Liver (75%) were confirmed as MDV infected. As a result, the current study showed that Marek's disease (MD) occurrence,
clinical and pathological symptoms, and severity of mortality were observed beyond the
reach of immunization. Therefore, it was advised that further research be done on the
molecular characterization and genomic type of the Marek's disease virus throughout the
entire nation.
