title: Antileishmania immunological tests for asymptomatic subjects living in a visceral leishmaniasis-endemic area in Brazil.
abstract: The objective of this study was to evaluate the behavior of different tests used for the diagnosis of visceral leishmaniasis (VL) in asymptomatic subjects living in an endemic area. No gold standard is available for the diagnosis of asymptomatic infection with Leishmania. In continuation of a previous study, 1,017 subjects living in a VL-endemic area were clinically reevaluated. Of these, 576 had at least one positive serological test in a first assessment. About 3 years after the first evaluation, none of the subjects had progressed to clinical VL. Among this group, 246 subjects were selected, and five serological tests (enzyme-linked immunosorbent assay p [ELISAp], ELISArK39, ELISArK26, indirect immunofluorescence test [IIFT] using L. amazonensis promastigote antigen, and an immunochromatographic test using rK39 antigen [TRALd]) and the Montenegro skin test (MST) were repeated. There was a significant increase in the number of subjects who tested positive in the MST, IIFT, ELISAp, and ELISArK39 in the second evaluation. For all tests, there were subjects who tested positive in the first evaluation and negative in the second evaluation. A positive result in the serological tests and MST in subjects from the endemic area studied did not indicate a risk of progression to VL and may only be temporary.
authors.affiliation: Department of Tropical Medicine and Infectology, Federal University of Triângulo Mineiro, Uberaba, Brazil. lalmeidas@dcm.uftm.edu.br
authors.forename: Luciana Almeida
authors.initials: LA
authors.lastname: Silva
authors.forename: Héctor Dardo
authors.initials: HD
authors.lastname: Romero
authors.forename: Gabriel Antônio
authors.initials: GA
authors.lastname: Nogueira Nascentes
authors.forename: Roberto Teodoro
authors.initials: RT
authors.lastname: Costa
authors.forename: Virmondes
authors.initials: V
authors.lastname: Rodrigues
authors.forename: Aluízio
authors.initials: A
authors.lastname: Prata
mesh_terms: D000953:Antigens, Protozoan / Q000276:immunology; D058345:Asymptomatic Infections / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005455:Fluorescent Antibody Technique; D006801:Humans; D007893:Leishmania donovani / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
chemical_list: D000953:Antigens, Protozoan