Detection of viruses associated with Bovine Respiratory Disease Complex in samples collected from Albanian cattle during 2022/23

The bovine respiratory disease complex causes significant morbidity and mortality with numerous aetiological agents known to contribute to its development including several bacteria and viruses. In Albania there is limited information on the prevalence or genetic makeup of viral bovine respiratory disease complex pathogens, which limits mitigation strategies and effective responses, such as targeted vaccination against circulating viruses. Nasal or pulmonary samples were collected from cattle in 2022/23, then PCR of bovine Betacoronavirus gravedinis (BoCoV) and Orthopneumovirus bovis (BRSV) was used to determine their prevalence in Albanian cattle with or without respiratory symptoms. From 105 cattle that were tested, 5 animals tested positive for BoCoV only, 5 animals tested positive for BRSV only and 1 animal tested positive for both BoCoV and BRSV. Four of the eleven positive animals had respiratory symptoms accounting for 8.3% of all symptomatic animals tested. There was an increased prevalence of viruses detected in animals sampled in farms or slaughterhouses within or neighbouring the region of Tiranë compared to other locations. Sequencing of genes encoding the surface proteins enabled phylogenetic analysis and genotyping of Albanian isolates. BoCoV spike and haemagglutinin esterase sequences sat in the European clade, with the spike sequences split across three lineages. BRSV isolates were either in subgroup II, with many other European isolates, or subgroup VIII with several Croatian isolates. This study has shown BoCoV and BRSV were not highly prevalent in cattle with respiratory symptoms in Albania at the time of sampling. Phylogenetic analyses showed the detected pathogens are closely related to isolates from other European countries and there have been multiple introductions of each.