Lyme disease (LD) is caused by a bacterial genospecies complex named Borrelia burgdorferi sensu lato (s.l.), which includes B. burgdorferi sensu stricto (B.b.s.s). Originally described in North America, LD has also been described in other parts of the Northern Hemisphere, and in Eurasia. Different B.b.s.l. species, transmitted through geographically diverse tick vectors, are associated with different clinical presentations of the disease. In recent years, the incidence and the endemic range of LD have steadily expanded to include areas of the world with tropical climate, including Latin American countries. Challenges in serological diagnosis. Inconsistent confirmatory results, despite clinical diagnosis, could be explained by antigenic differences between these new species in these countries, with American strains used in the elaboration of commercial tests. This could explain indeterminate Western blots and polymerase chain reactions in detecting suspected LD cases. Novel Borrelia taxons may impact the reservoir host spectrum, including mammals, birds, and other animals. Different species of Ixodes ticks are found in Latin America, where I. scapularis is absent, and they could serve as vectors. New genospecies of B.b.s.l. and the scarce information about its pathogenicity, reservoirs and vectors, highlights the importance of further studies tp elucidate their genetic differences in the context of the development of innovative diagnostic and clinical approaches. Knowledge gaps and the need for prospective and rigorous studies, to determine the presence, or not, of LD in this region, warrant call for research providing new insights into the basic biology and epidemiology, and clinical manifestations in this region.
Mesa et al. (2026) studied this question.