Abstract
BackgroundVisceral Leishmaniasis in humans presents with fever, anemia, and splenomegaly and can be lethal if not treated. Nevertheless, the majority of Leishmania infantum-infected individuals does not manifest symptoms and remain so provided they are not immunosuppressed. In this work, the performance of different tests was evaluated to detect asymptomatic individuals who were living in Teresina, Piauí state, Brazil, an endemic area for VL.MethodologyL. infantum-specific antibodies were detected by ELISA and two different rapid immunochromatographic (IC) diagnostic tests, Kalazar Detect and OnSite, and parasitic loads were detected by real time PCR [qPCR]. Additionally, we measured levels of the biomarkers monokine induced by IFN-γ (MIG) and IFN-γ-induced protein 10 (IP-10) before and after stimulation of whole blood with soluble Leishmania antigen [SLA].Principal findingsKalazar Detect and OnSite detected, respectively, 76% and 64% of patients presenting with active Visceral Leishmaniasis; 50% and 57% of patients remained positive in these tests, respectively, after treatment. Of the healthy participants in the study who were living in the endemic area, only 1.7% were positive with both of the IC tests. On the other hand, reactivity in ELISA tests revealed that 13% of these individuals presented asymptomatic infections; among VL patients, 84% presenting with active disease were reactive in ELISA, and after treatment, 55.5% were seropositive. L. infantum DNA was present in the blood of 37.9% of infected individuals living in the endemic area, while IP-10 and MIG biomarkers were detected in 26.7% of them. The greatest concordance of positivity occurred between ELISA and qPCR.ConclusionThe association of different techniques can detect asymptomatic infections, however, more research is necessary to develop ideal biomarkers that are simple to use in the clinic and in field studies in areas endemic for Visceral Leishmaniasis.
Highlights
Visceral Leishmaniasis (VL) is classified by the World Health Organization as a neglected tropical disease due to high mortality rates, low attention given by the public sector and high endemicity in poor regions around world [1]
The association of different techniques can detect asymptomatic infections, more research is necessary to develop ideal biomarkers that are simple to use in the clinic and in field studies in areas endemic for Visceral Leishmaniasis
The mean age of the group of infected individuals presenting with active VL (VL) or after treatment of VL (AT) was 40 years, while for all other individuals who were living in the endemic area, before testing to separate asymptomatic infections with L. infantum (ASYMP) from uninfected endemic controls (EC) the mean age was 39 years and for non-endemic uninfected controls was 32 years (Table 1)
Summary
Visceral Leishmaniasis (VL) is classified by the World Health Organization as a neglected tropical disease due to high mortality rates, low attention given by the public sector and high endemicity in poor regions around world [1]. Caused by Leishmania infantum [synonymous L. chagasi] in the New World or L. donovani in the Old World, VL can be classified as an anthroponotic or zoonotic disease because it is transmitted between humans and others mammals, such as dogs [2,3]. In endemic areas in Brazil most people infected with L. infantum remain asymptomatic provided they are not immunosuppressed. In addition to dogs, asymptomatic humans can represent an important reservoir and contribute to the maintenance of the pathogen in the endemic area [9,10]. The majority of Leishmania infantum-infected individuals does not manifest symptoms and remain so provided they are not immunosuppressed. The performance of different tests was evaluated to detect asymptomatic individuals who were living in Teresina, Piauı state, Brazil, an endemic area for VL
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
