Epidemiological situation of human leptospirosis in Brazil and challenges in its diagnosis with a focus on molecular approaches

Leptospira interrogans is one of the causative agents of human leptospirosis, a zoonotic disease with worldwide distribution. Nowadays, this zoonosis is considered one of the biggest in terms of morbidity and mortality (even considering Dengue, the major arbovirosis affecting humans), having in Brazil 3,800 human cases per year. Currently, difficulties imposed by the absence of a rapid, sensitive diagnostic test that can be used as a routine test for the detection of leptospirosis lead to misdiagnosis and underreported cases. The gold standard diagnostic test for leptospirosis is the microscopic agglutination test (MAT), which presents difficulties in execution and interpretation. Therefore, this review proposes a general view of the epidemiologic situation of the disease in Brazil, in addition to the current contributions in the literature for the development of new diagnostic methods. Amongst them, the gene sequences polymorphism analysis, which presents potential for phylogenetic and populational analysis and genotyping of Leptospira spp.