Epidemiological Diversity, Isolation, and Molecular Characterization of Circulating Contagious Ecthyma Virus (Orf Virus) in Goats of Bangladesh

Orf virus (ORFV), which belongs to the Poxviridae family, is the source of the extremely contagious disease known as Contagious Ecthyma (CE) or Orf in sheep and goats. In Bangladesh, CEV continually exists in goats and is associated with mortality and weight loss. To extract, identify, and characterize the circulating ORFV from goats suspected of having CE, a study was conducted. Based on the age, sex, and season of the goats, a total of 100 CE suspect samples were collected from goats in various parts of Bangladesh, such as Dhaka, Rajshahi, Bandarban, Meherpur, Mymensingh, and Chuadanga. After that, DNA was extracted, and a PCR test was run to amplify the ORFV VIR and GIF genes. Isolation of the virus was performed using Lamb testicular cell (LTC) for detecting these two genes. The univariate linear regression model showed a higher prevalence in Mymensingh district (70%) and subsequently lower prevalence in Bandarban districts (50 %). The prevalence was higher in the younger age group of 6–12 years (77.27%), with female goats (63.49%) and the winter season (75.61%) being the most susceptible. Three to seven days post inoculation (dpi), rounding and detaching appearance were seen in PCR-positive samples of ORFV with two isolates (GIF and VIR) in primary lamb testicular cells (LTC). Sequencing of these two isolates results in 99-100% homology to each other and our circulating isolates are closely related with some Indian and Chinese variants. In conclusion, it can be stated that contagious ecthyma (Orf) is prevalent in Bangladesh and more genomic analysis should be performed for control.