Cocirculacion y reemplazo de variantes de SARS-CoV-2 en espacios hacinados y poblaciones marginadas en la frontera Mexico-EUA

Objective. To interrogate the circulating SARS-CoV-2 lineages and recombinant variants in persons living in migrant shelters and persons who inject drugs (PWID). Materials and methods. We combined data from two studies with marginalized populations (migrants in shelters and persons who inject drugs) in Tijuana, Mexico. SARS-CoV-2 variants were identified on nasal swabs specimens and compared to publicly available genomes sampled in Mexico and California. Results.All but 2 of the 10 lineages identified were predominantly detected in North and Central America. Discrepancies between migrants and PWID can be explained by the temporal emergence and short time span of most of these lineages in the region. Conclusion. The results illustrate the temporo-spatial structure for SARS-CoV-2 lineage dispersal and the potential co-circulation of multiple lineages in high-risk populations with close social contacts.These conditions create the potential for recombination to take place in the California-Baja California border.