New record of preclinical diagnosis of American visceral leishmaniasis in Amazonian Brazil encourages optimizing disease control.

The clinical-immunological spectrum of human -infection in Amazonian Brazil has recently been reviewed based on the combined use of the delayed-type hypersensitivity (DTH) and indirect fluorescence antibody test (IFAT-IgG/IgM), both with homologous -antigens, and associated with the clinical evaluation of infected individuals. This diagnostic approach has allowed to identify the broadest clinical-immunological spectrum of human -infection composed by five clinical-immunological profiles of infection: three asymptomatic, 1) Asymptomatic Infection (AI) [DTH, IFAT], 2) Subclinical Resistant Infection (SRI) [DTH, IFAT], and 3) Indeterminate Initial Infection (III) [DTH, IFAT], and two symptomatic ones, 4) Symptomatic Infection (SI) [=American visceral leishmaniasis - AVL] and, 5) Subclinical Oligosymptomatic Infection (SOI), both with the same immune profile [DTH, IFAT]. Herein, we confirm for the third time the preclinical diagnosis of AVL through IgM-antibody response in an early asymptomatic case of infection (profile III), a 17-year-old boy who evolved to AVL (=profile SI) six weeks after the initial infection diagnosis, confirming that the combined use of DTH and IFAT-(IgG/IgM) assays associated with the clinical evaluation of infected individuals is potentially useful for monitoring human -infection in endemic areas as well as optimizing AVL control.