Short report: Isolation of two vaccinia virus strains from a single bovine vaccinia outbreak in rural area from Brazil: Implications on the emergence of zoonotic orthopoxviruses.

Outbreaks of bovine vaccinia disease caused by circulation of Vaccinia virus (VACV) strains have been a common occurrence in Brazil in the recent years, being an important emergent zoonosis. During a single outbreak that took place in 2001, two genetically different VACV strains were isolated and named Guarani P1 virus (GP1V) and Guarani P2 virus (GP2V). Molecular diagnosis was done through restriction fragment length polymorphism (RFLP) of ati gene (A26L) and by sequence analysis of a group of five VACV genes including the C11R, J2R, A56R, B18R, and E3L genes. These findings confirmed the co-circulation of two different Vaccinia virus strains during the same outbreak, raising important questions about the origin, emergence, and circulation of VACV strains in Brazil.