Genomic insights into the mpox outbreak in Uruguay

Uruguay reported a limited mpox outbreak during the 2022 global clade IIb epidemic, yet no genomic data from the country had been publicly available. Here, we generated and analyzed the first 17 monkeypox virus genomes from Uruguay, sampled during the 2022 outbreak and representing approximately 85% of the 20 confirmed national cases reported as of 2025. Phylogenetic inferences integrated with travel history and contact-tracing data identified evidence of up to eight independent viral introductions involving lineages B.1, B.1.2, and B.1.6, with events linked to travel from Brazil, Argentina, and Chile, while local transmission chains remained short and geographically restricted. These findings suggest that Uruguay’s small outbreak was driven not by fewer viral introductions, but by limited onward transmission. As the first genomic characterization of mpox in Uruguay, this study reinforces the importance of integrating genomic surveillance with epidemiological investigations during emerging outbreaks.