Contagious Eczema (CE), caused by ORFV, impacts sheep and goats globally, with severe symptoms and economic losses. The ORFV situation in Yunnan, China, was unclear before 2021–2023 study. Eleven scab samples from goats on small farms in three Yunnan municipalities were collected. Four ORFV strains were isolated and characterized using scanning electron microscopy, cytopathic effect observation, and PCR. Phylogenetic analyses of ORFV011 and ORFV059 genes showed significant results. For ORFV011, the nucleotide similarity of the four strains to D1701 strain was 98.4–99%. For ORFV059, it was 97.2–97.9% with OV-SA00 strain. These findings suggest gene rearrangements and interactions among strains during Yunnan’s ORFV outbreak, forming a unique evolutionary lineage. Our study is the first comprehensive one on Yunnan’s ORFV prevalence with in-depth phylogenetic analysis. It has important implications. In vaccine development, understanding genetic variances helps create better vaccines. For disease control, customized strategies like targeted quarantine and disinfection can be designed based on strain characteristics. From a public health aspect, as CE is zoonotic, closely monitoring ORFV in goats aids in predicting and preventing human infections, thus being significant for protecting goats against CE in Yunnan.
In China, the Akabane virus (AKAVs) has been reported in several host species. However, data regarding goats is still showing a gap. Akabane virus (AKAV) is an insect-borne virus from the Peribunyaviridae family that in ruminant species, particularly affects pregnant animals, resulting in abortions, stillbirths, and premature broth, often with congenital abnormalities. Therefore, there is a dire need to understand the diversity of this virus in ruminants, particularly in goats. The current study aimed to investigate the genotype characteristics of goat-originated AKAVs in Yunnan, China. For this, blood samples from goats were collected for four consecutive years (2019–2023) during routine disease surveillance in Yunnan province. The serum was harvested and evaluated for the seroprevalence of the AKAVs. The seroprevalence analysis revealed that the majority of goats in Yunnan province are infected with AKAVs, with a detected prevalence of 7.69% (92/1,197 tested), even though detected seroprevalence rose as high as 27.8% in some areas. For the evolutionary analysis of AKAVs of goat, five AKAVs strains were isolated from AKAV serum-positive goat blood samples were whole genome sequenced. The phylogenetic analysis (sequenced small and medium segments) classified the AKAVs into Ia and Ib genogroups, with Ia genogroup strains being more common in Yunnan goats. However, genotype II (TJ2016 and CQ-AKAV-1-2023) emerged in China. Overall, this study emphasizes the importance of implementing prevention and control strategies for AKAVs diseases transmitted in Yunnan, China.
Bovine rotavirus (BRV) poses a major threat to the global cattle industry, driving significant morbidity and mortality in young calves. In Yunnan Province, China, BRV is the primary cause of neonatal calf diarrhea (NCD), yet the molecular epidemiology of circulating strains remains poorly understood. This study aimed to investigate the molecular characteristics of bovine rotavirus strains associated with a severe outbreak of the NCD on a local farm. Fecal samples were collected from 396 calves and screened for BRV by RT-PCR targeting the VP6 gene. Positive samples were subjected to virus isolation in MA104 cells, followed by whole-genome sequencing, phylogenetic analysis, and pathogenicity assessment in suckling mice. Of 396 samples, 85 tested positive for BRV, corresponding to an animal-level prevalence of 21.5% (95% CI: 17.5–25.8%), with four fatalities recorded. A strain designated as BRV-YN1-2021 was successfully isolated, exhibiting characteristic cytopathic effects, specific immunofluorescence, and typical rotavirus morphology by electron microscopy. Genomic analysis revealed the constellation G8-P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H3, identified as genotype G8P[1]. BLAST analysis showed that four genomic segments shared the highest identity with deer rotavirus strains, five with human rotavirus strains, and two with bovine rotavirus strains. Phylogenetic analysis demonstrated close relationships with US deer strains, Japanese bovine strains, and human strains circulating in China. Experimental infection in suckling mice induced diarrhea and significant intestinal histopathology, degeneration of villous epithelial cells, goblet cell hyperplasia, and inflammatory infiltration. This study reports the first isolation of a G8P[1] bovine rotavirus from a diarrhea outbreak in Chinese cattle. The multi-host genetic composition provides evidence of interspecies reassortment events, highlighting the zoonotic potential of BRV and emphasizing the need for continuous molecular surveillance to inform effective control strategies.
Group A rotaviruses (RVA) have been identified as the leading cause of neonatal calf diarrhea (NCD) In Yunnan, China, despite the limited documentation on this issue within the country. Given the significant impact on animal health and welfare, further attention is warranted to comprehend the prevalence and epidemiology of this disease. In this study, we isolated RVA strains from NCD clinical samples to support RVA epidemic study and further disease control in Yunnan. Material and Methods: Ten fecal samples were obtained from calves with a single episode of neonate calf diarrhea from a farmer during a severe NCD outbreak. For the diagnosis of Group A rotavirus (RVA) infection, fecal reverse transcription-polymerase chain reaction (RT-PCR) was employed as the primary method. Subsequently, RVA isolation was conducted on MA104 cells, with inoculates being pretreated with trypsin TPCK to enhance viral infectivity. The isolated RVA strain was further confirmed through RT-PCR and immunofluorescence assay. Results: RVA virus was isolated from clinical samples following six passages depended on trypsin treatment of inoculates. The sign of CPE detected consisted of increased cell granularity, obscure cell boundaries, cell rounding, and eventual degeneration and detachment of cells. Analysis of sequencing revealed that field isolates was of group A serotype. Phylogenetic analysis based on the ORF sequences of the VP4 and VP7 sequences segments indicated that the isolate was classified as the P[1] genotype. VP4 gene of strain YN-1 shares 75.2%-99.7% nucleotide identity of and 81.6%–99.7% amino acid identity with the complete VP4 sequences of the P[1]. The complete VP7 gene of YN-1 is 981 nucleotide long and encode 326 amino acids. The RotaC v2.0 analysis classified the sequence as the G8 genotype. The VP7 gene of strain YN-1 shares 88.5%-97.7% nucleotide identity and 94.2%-99.1% amino acid identity. Conclusion: This is the first study in China which reports the circulation of Group A NCD on cattle farms in the field. Our study constitutes a crucial and a necessary step allowing preventive and veterinary medicine to support RVA disease controls in Yunnan province, China.