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

Luciana Lima; Thiago Vasconcelos-Dos-Santos; Marliane Campos; Patrícia Karla Ramos; Claudia Gomes; Marcia Laurenti; Vania da Matta; Carlos Corbett; Fernando Silveira

doi:10.1016/j.parepi.2020.e00154

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

Parasite Epidemiol Control. 2020 May 8:10:e00154. doi: 10.1016/j.parepi.2020.e00154. eCollection 2020 Aug.

Authors

Luciana Lima¹, Thiago Vasconcelos-Dos-Santos¹, Marliane Campos¹, Patrícia Karla Ramos¹, Claudia Gomes², Marcia Laurenti², Vania da Matta², Carlos Corbett², Fernando Silveira^{1

3}

Affiliations

¹ Parasitology Department, Evandro Chagas Institute, Ananindeua, Para State, Brazil.
² Pathology Department, Medical School of São Paulo University, São Paulo, São Paulo State, Brazil.
³ Nucleus of Tropical Medicine, Federal University of Pará, Belém, Para State, Brazil.

Abstract

The clinical-immunological spectrum of human Leishmania (L.) infantum chagasi-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 L. (L.) infantum chagasi-antigens, and associated with the clinical evaluation of infected individuals. This diagnostic approach has allowed to identify the broadest clinical-immunological spectrum of human L. (L.) infantum chagasi-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 L. (L.) infantum chagasi-infection in endemic areas as well as optimizing AVL control.

Keywords: Amazonian Brazil; American visceral leishmaniasis; Disease control; Leishmania (L.) infantum chagasi; Preclinical diagnosis.