Isolation and Molecular Characterization of Camelpox Virus in Dromedary Camels from Outbreak Cases in Borena, Ethiopia

An outbreak investigation of camelpox in dromedary camels (Camelus dromedarius) was conducted from October 2024 to May 2025 in Borena Zone, Ethiopia, with the aims of isolating, confirming the etiology and molecular characterization of camelpox virus from outbreak cases. The study integrated clinical assessment, virus isolation using Vero cell lines, and molecular characterization using conventional PCR, real-time PCR, sequencing and phylogenetic analysis. Clinically affected camels manifested typical pox-like lesions, fever and swollen lymph nodes, with a morbidity rate of 33.8% (24/71) and a case fatality rate of 4.2% (1/24). The virus was successfully isolated showing typical cytopathic effects of rounding of cells, syncytia, giant cell formation, aggregation and detachment. Conventional PCR targeting A-type inclusion protein (ATIP) gene amplified the expected 881 bp fragment with 26.3% positivity in both skin scab and nasal swab samples. Real-time PCR employing high-resolution melting curve analysis detected the viral DNA in 52.6% of samples with a melting temperature of 73.00 ± 0.20 °C for CMPV. Sequencing of the ATIP gene showed 100% nucleotide similarity with reference CMPV strains of CMPV M-96, CMPV CMS, strain 0408151v and CMPV genome (NC_003391), although a single nucleotide variation was noted when compared to the previously reported Ethiopian isolates (KU705085-KU705110) and Israeli isolates (MK910851 and MZ300856), and two nucleotide mismatches were observed with Sudanese isolates (KT931624 and KT931625). Phylogenetic analysis revealed that the current isolates clustered with CMPV strains of CMPV M-96, CMPV CMS, strain 0408151v and others but were distinct from previously reported Ethiopian isolates. This study provides significant insights on early diagnosis and control strategies.