Predicting Kala-Azar Disease Manifestations in Asymptomatic Patients with Latent
            <i>Leishmania donovani</i>
            Infection by Detection of Antibody against Recombinant K39 Antigen

Singh, Sarman; Kumari, Veena; Singh, Namit

doi:10.1128/cdli.11.6.1199.2004

Cited by 16 publications

(21 citation statements)

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“…Unfortunately, there have been too few longitudinal studies to be able to predict when or if an asymptomatic infection with L. donovani will become clinically manifest (Schaefer et al, 1995;Singh et al, 2002), and the detection of such infection can be difficult. The most specific diagnostic test for VL is the demonstration in bone-marrow or splenic aspirates of either parasites, by culture or the microscopical examination of smears, or of parasite DNA, in PCR-based assays (Schallig et al, 2001).…”

Section: )mentioning

confidence: 97%

Usefulness of the direct agglutination test in the early detection of subclinicalLeishmania donovaniinfection: a community-based study

Bimal

Das

Sinha

et al. 2005

Annals of Tropical Medicine & Parasitology

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The value of a direct agglutination test (DAT) in the detection of subclinical infections with Leishmania donovani has recently been investigated in the Indian state of Bihar, after the sensitivity and specificity of the test had been determined. When used to screen sera from 108 parasitologically confirmed cases of visceral leishmaniasis, 50 patients with active, non-leishmanial infection, and 641 healthy controls living close to, or distant from, an endemic area, the test was found to be 91.7% sensitive and 100% specific if a titre of 1:800 was used as the threshold for seropositivity. During a longitudinal clinical study in a rural, VL-endemic area of the Indian state of Bihar, the test was used, with 1:800 set as the threshold titre, to determine the baseline prevalence of infection with L. donovani among villagers who, though showing no symptoms of VL, had recently been febrile for at least 2 weeks. The 234 subjects of this study were either VL-case contacts [i.e. members of households in which there were active or cured VL cases (N=78)] or the members of control households with no cases or history of the disease (N=156). The results of DAT at the start of the study indicated that 49 (20.9%) of the subjects--29 (37.2%) of the VL-case contacts and 20 (12.8%) of the other subjects--were seropositive and therefore probably had subclinical infections with L. donovani. During the subsequent 9 months of follow-up, however, only eight of the subjects found seropositive at the start of the study--seven (24.1%) of the seropositive case contacts but only one (5.0%) of the other seropositives--developed symptomatic VL, all by month 6 of the follow-up. Compared with their neighbours, therefore, individuals who shared households with active or cured cases of VL appeared at greater risk not only of L. donovani infection (indicating focal transmission) but also of developing symptomatic disease once infected. Curiously, among the seropositive case contacts, those from the households that harboured active cases of VL at the baseline survey were less likely to develop symptomatic VL during the 9 months of follow-up than those from households that harboured only cured cases (18.8% v. 30.8%). The wide-spread use of DAT could allow the detection and early treatment of latent L. donovani infections and so contribute to the elimination of VL, at least as a public-health problem, from India.

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Section: )mentioning

confidence: 97%

Usefulness of the direct agglutination test in the early detection of subclinicalLeishmania donovaniinfection: a community-based study

Bimal

Das

Sinha

et al. 2005

Annals of Tropical Medicine & Parasitology

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“…The annual incidence of VL in India is approximately 100,000 cases, with Bihar accounting for .90% of them (Bora, 1999). Over the last decade it has become clear that, at least in India, the prevalence of asymptomatic human infection with L. donovani is much higher than that of VL (Singh et al, 2002;Bimal et al, 2005). Although it would be useful to be able to predict who will develop VL or, at least, identify those at high-risk of the disease, in the absence of adequate longitudinal studies, it is unclear what percentage of those infected with the parasite will ever develop symptomatic disease and how quickly symptomatic disease develops post-infection (Schaefer et al, 1995;Singh et al, 2002).…”

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confidence: 99%

A community-based, comparative evaluation of direct agglutination and rK39 strip tests in the early detection of subclinicalLeishmania donovaniinfection

Sinha

Bimal²,

Pandey³

et al. 2008

Annals of Tropical Medicine & Parasitology

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In the Indian state of Bihar, the sensitivities and specificities of direct agglutination tests (DAT) and rK39 test strips for the detection of Leishmania donovani infection in humans were explored and found to be generally good (92%-100%). When 172 asymptomatic individuals [16 'case-contacts' who lived in the same households as past or current, confirmed cases of visceral leishmaniasis (VL) and 156 other subjects from neighbouring households] were tested, the same 36 (21%) individuals, including all 16 'case-contacts', were found seropositive using each type of test. When followed-up after 3 months, 18 of the individuals who had been found seropositive in the baseline survey remained seropositive, and eight (44%) of these had developed symptomatic VL, with amastigotes in their splenic aspirates. Seven (44%) of the 16 'case-contacts' but only one (5%) of the other 20 subjects found seropositive at baseline went on to develop VL within 3 months. Although the strip test appeared slightly better than DAT for predicting the development of VL in the 172 subjects, either type of test may be very useful for the early detection of asymptomatic L. donovani infection and thus the identification of those at relatively high risk of developing VL.

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“…May be positive due to the past occurrence of VL Zijlstra et al 1998;Salotra et al 2003 Western blotting Zijlstra et al 1998;Salotra et al 2003 ELISA 96 96 High sensitivity even for PKDL cases with macular presentation. Relative long incubation (18 h), need for serial dilutions, no prognostic value Haldar et al 1981;Saha et al 2005;Salotra et al 1999;Singh et al 2002DAT el Harith et al 2003 Prom. antigen 98.5 96.5 Zijlstra et al 1998;Singh et al 2005 Amastigote The DAT assay using aqueous/freeze-dried antigen shows excellent sensitivity in various studies in most VL-endemic areas.…”

Section: Rapid Diagnostic Tests For Application In the Fieldmentioning

confidence: 99%

Diagnosis of visceral leishmaniasis: developments over the last decade

et al. 2011

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Diagnostic parameters for visceral leishmaniasis (VL), a potentially fatal parasitic disease caused by Leishmania donovani, have been redefined in the last decade with the development of serological and molecular tests, though a definitive diagnosis still banks on the century-old parasitological methods in many areas. Recombinant antigens have improved performance of serodiagnostic methods. Serology-based tests, rk39 antigen dipstick, and direct agglutination test commonly employed in the field are highly sensitive methods, however, fail to distinguish past infections. Molecular approaches have become increasingly relevant due to remarkable sensitivity, specificity, and flexibility in choice of samples. Quantitative polymerase chain reaction is a highly sensitive and specific tool used in referral labs for detection/assessment of parasite load in VL patients and subsequently in monitoring treatment response to antileishmanial agents. The method displays potential to provide threshold for distinguishing asymptomatics in endemic areas. Currently, improvement in VL diagnostics is required for successful decentralized (point-of-care) testing in field conditions and to detect VL-HIV co-infection. Techniques such as loop-mediated isothermal amplification offer a reliable molecular diagnostic method for field application. The diagnosis based on bioanalytics/biosensors promise frontiers for point-of-care VL detection after adequate standardization. This review summarizes the recent developments in VL diagnostics, drawing attention towards the need for standardization of the diagnostics across the affected regions.

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Predicting Kala-Azar Disease Manifestations in Asymptomatic Patients with Latent Leishmania donovani Infection by Detection of Antibody against Recombinant K39 Antigen

Cited by 16 publications

References 0 publications

Usefulness of the direct agglutination test in the early detection of subclinicalLeishmania donovaniinfection: a community-based study

Usefulness of the direct agglutination test in the early detection of subclinicalLeishmania donovaniinfection: a community-based study

A community-based, comparative evaluation of direct agglutination and rK39 strip tests in the early detection of subclinicalLeishmania donovaniinfection

Diagnosis of visceral leishmaniasis: developments over the last decade

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