Bovine viral diarrhea virus (BVDV) is an economically relevant pathogen affecting cattle production and reproduction worldwide. We report the coding-complete sequences of two BVDV-1a subtype isolates, circulating in Uruguay.

In a beef cattle breeding farm located in northern Uruguay, an Aberdeen Angus calf was born with complex anomalies. The offspring was sired by one of the bulls of the farm. The calf died shortly after birth, displaying multiple malformations at external examination, including agenesis of the lumbar, sacral and coccygeal vertebrae and spinal cord and arthrogryposis of both pelvic limbs, characteristic of perosomus elumbis (PE). At necropsy there was also brachygnathia and muscle atrophy of the pelvic limbs, along with underdeveloped small intestines, atresia ani, ectopia of the left kidney and hypoplasia of the contralateral, testicular fusion and cryptorchidism. Molecular studies of the fetal tissues revealed infection with Bovine Viral Diarrhea Virus (BVDV), an agent known for causing different malformations in cattle.

Bovine viral diarrhea virus (BVDV) is a pathogen of worldwide economic importance. In Uruguay, BVDV is endemic, with seroprevalence >80% at the farm level. This study analyzed 912 samples collected from January 2018 to October 2024 by reverse transcription PCR and sequencing, from calves with diarrhea, aborted fetuses, heifers with a history of abortions, and animals exhibiting symptoms of Mucosal Disease. This work summarizes ten years (2014–2024) of molecular epidemiology and evolution of BVDV. Analysis of the BVDV 5′UTR/N^pro genomic region revealed that the BVDV-1a, 1e, 1i, and 2b subtypes circulate in Uruguay. BVDV-1a remains the most prevalent subtype, followed by BVDV-2b, whose prevalence has been increasing. Our previous studies revealed that BVDV-1a showed geographical diversification in Uruguay. In this work, evolutionary studies conducted with N^pro genomic region showed that BVDV-2b is evolving at a substitution rate of 6.09 × 10⁻⁴ substitutions/site/year and has been introduced from Brazil in six separate events between 1870 and 1928, showing no geographical diversification. This work demonstrates that BVDV-1a and BVDV-2b are evolving differently in Uruguay. This evolutionary divergence is notable when comparing patterns observed in other countries where these subtypes circulate. Our findings provide crucial knowledge that should be considered for developing effective BVDV control measures in Uruguay.