Genomic Insights into the Spread of Vaccinia Virus Strain Cantagalo to Rural Regions of Northeastern Brazil.

Vaccinia virus strain Cantagalo (CTGV) causes a pustular disease in dairy cows and milkers in Brazil. Outbreaks in several states have been frequently reported, but the full genome sequence and genomic analysis of isolates from the Northeast region have never been described. Here, we report CTGV outbreaks in two Northeastern states, affecting milkers, lactating cows, and suckling calves. The farms were located in the main dairy belt of Pernambuco, in the Borborema Plateau, and in a rural region of Bahia. Of the 12 samples that tested positive for CTGV, five had their genomes fully sequenced. They cluster with CTGV isolates from Goiás (Midwest region, 2022) and São Paulo (Southeast region, 2023) but diverge from isolates from the Southeast in the early 2000s. Two clinical isolates have accumulated greater genetic variability and segregate separately from the other three isolates from the Northeast, showing evidence of potential recombination events with the FAI-01 isolate from the Midwest region (2022). We also detected Parapoxvirus and CTGV coinfection in some animals. These findings likely suggest different episodes of virus introduction in these states. The spread of CTGV raises concerns about the potential impact on local economic activities and underscores the importance of avoiding raw milk consumption.