Vidya Nand Rabi Das

Asymptomatic infection with visceral leishmaniasis in a disease-endemic area in bihar, India.

A prospective study was carried out in a cohort of 355 persons in a leishmaniasis-endemic village of the Patna District in Bihar, India, to determine the prevalence of asymptomatic persons and rate of progression to symptomatic visceral leishmaniasis (VL) cases. At baseline screening, 50 persons were positive for leishmaniasis by any of the three tests (rK39 strip test, direct agglutination test, and polymerase chain reaction) used. Point prevalence of asymptomatic VL was 110 per 1,000 persons and the rate of progression to symptomatic cases was 17.85 per 1,000 person-months. The incidence rate ratio of progression to symptomatic case was 3.36 (95% confidence interval [CI] = 0.75-15.01, P = 0.09) among case-contacts of VL compared with neighbors. High prevalence of asymptomatic persons and clinical VL cases and high density of Phlebotomus argentipes sand flies can lead to transmission of VL in VL-endemic areas.

Effectiveness and safety of liposomal amphotericin B for visceral leishmaniasis under routine program conditions in Bihar, India.

We evaluated, through the prospective monitoring of 251 patients at Sadar Hospital in Bihar, India, the effectiveness and safety of 20 mg/kg body weight of liposomal amphotericin B for the treatment of visceral leishmaniasis. The treatment success rates for the intention-to-treat, per protocol, and intention-to-treat worse-case scenario analyses were 98.8%, 99.6%, and 81.3%, respectively. Nearly one-half of patients experienced mild adverse events, but only 1% developed serious but non-life-threatening lips swelling. The lost to follow-up rate was 17.5%. Our findings indicate that the 20 mg/kg body weight treatment dosage is effective and safe under routine program conditions. Given that the exorbitant cost of liposomal amphotericin B is a barrier to its widespread use, we recommend further study to monitor and evaluate a lowered dosage and a shorter treatment course.

A controlled, randomized nonblinded clinical trial to assess the efficacy of amphotericin B deoxycholate as compared to pentamidine for the treatment of antimony unresponsive visceral leishmaniasis cases in Bihar, India

Background: There is significant variation in Amphotericin B (AMB) efficacy and relapses in antimony unresponsive visceral leishmaniasis (VL) cases over a period of time (10–15 years). Keeping in mind the above mentioned view this study was undertaken with an objective to assess the magnitude of cure and relapse rates of AMB in the treatment of antimony unresponsive VL cases. Methods: In a controlled, randomized nonblinded clinical trial, we evaluated the cure and relapse rate of Amphotericin B deoxycholate as compared to pentamidine. A total of 82 sodium stibogluconate (SSG) unresponsive and parasitologically confirmed VL cases were included in this study and randomized into two groups, test (Amphotericin B) and control (Pentamidine). Both the groups were treated with recommended dosages (as per World Health Organization guidelines) of respective medicines. All the patients were followed up on 1st, 2nd, and 6th month after end of treatment. Results: Apparent cure rate in the Amphotericin B group was found to be 95% (39/41) compared with 83% (34/41) in the Pentamidine group, which shows significant statistical difference (p = 0.05). The ultimate cure rate was found 92% (38/41) in the Amphotericin B group compared to 73% (30/41) in the Pentamidine group, which shows a significant statistical difference (Yates corrected chi-square = 4.42, p = 0.04). Similarly, significant statistical difference was observed in the relapse rate of the Amphotericin group compared to the Pentamidine group (p = 0.03). Conclusions: AMB may still be the drug of choice in the management of resistant VL cases in Bihar, India. This is due to its consistent apparent cure rate (95%), low relapse rate (2.5%), and cost effectiveness compared with other available antileishmanial drugs. It is a safe drug even in case of pregnancy. Efforts should be taken to form a future strategy so that this drug and coming newer drugs do not meet a similar fate as has happened to SSG and pentamidine over a span of 10–15 years.

Clinical epidemiologic profile of a cohort of post-kala-azar dermal leishmaniasis patients in Bihar, India.

Post-kala-azar dermal leishmaniasis (PKDL) has important public health implications for transmission of visceral leishmaniasis (VL). Clinical and epidemiologic profiles of 102 PKDL patients showed that median age of males and females at the time of diagnosis was significantly different (P = 0.013). A significant association was observed between family history of VL and sex of PKDL patients (χ(2) = 5.72, P < 0.01). Nearly 33% of the patients showed development of PKDL within one year of VL treatment. The observed time (median = 12 months) between appearance of lesions and diagnosis is an important factor in VL transmission. A significant association was observed between type of lesions and duration of appearance after VL treatment (χ(2) = 6.59, P = 0.001). Because PKDL was observed during treatment with all currently used anti-leishmanial drugs, new drug regimens having high cure rates and potential to lower the PKDL incidence need to be investigated.

Evaluation of rK-39 Strip Test Using Urine for Diagnosis of Visceral Leishmaniasis in an Endemic Region of India

The definitive diagnosis of visceral leishmaniasis (VL) requires invasive procedures for demonstration of parasites in tissue smear or culture. These procedures need expertise and laboratory supports and cannot be performed in the field. The aim of the present study was to evaluate the existing rK-39 immunochromatographic nitrocellulose strips test (ICT) with some modification in human urine for diagnosis of VL. The test was performed on both sera and urine samples on the same 786 subjects (365 confirmed VL and 421 control subjects). The sensitivity of the rK-39 ICT in serum was 100%, whereas the specificity was 93.8%, 100%, and 96.2% in healthy controls from endemic, non-endemic, and other infectious diseases, respectively. However, in urine samples, the test showed 96.1% sensitivity and 100% specificity. Considering sensitivity and feasibility of the test in the field, rK-39 ICT using urine samples can be an alternative to conventional invasive VL diagnosis.

Comparative Evaluation of PCR and Imprint Smear Microscopy Analyses of Skin Biopsy Specimens in Diagnosis of Macular, Papular, and Mixed Papulo-Nodular Lesions of Post-Kala-Azar Dermal Leishmaniasis

ABSTRACT Diagnosis of post-kala-azar dermal leishmaniasis (PKDL), particularly the macular form, is difficult when based on microscopy. This study compared the results of nested PCR (91.9% positive samples) with imprint smear microscopy (70.9% positive samples) for 62 PKDL samples. We found that nested PCR, which indicated 87.5% positivity for the macular lesions, compared to 41.6% positivity by imprint smear microscopy, is an efficient method for early diagnosis of PKDL.

Vaccine potential of HLA A2 epitopes from Leishmania Cysteine Protease Type III (CPC)

Although the precise host‐defence mechanisms are not completely understood, T‐cell‐mediated immune responses are believed to play a pivotal role in controlling parasite infection. In this study, the potential HLA*A2 restricted peptides were predicted and the ability of peptides to bind HLA‐A*02 was confirmed by a MHC stabilization assay. Two of the peptides tested stabilized HLA‐A*02: (a) LLATTVSGL (P1) and (b) LMTNGPLEV (P3). The potential of the peptides to generate protective immune response was evaluated in patients with treated visceral leishmaniasis as well as in healthy control subjects. Our data suggest that CD8+ T‐cell proliferation against the selected peptide was significantly higher compared to unstimulated culture conditions. The stimulation of peripheral blood mononuclear cells with epitopes individually or as a cocktail upregulated IFN‐γ production, which indicates its pivotal role in protective immune response. The IFN‐γ production was mainly in a CD8+ T‐cells‐dependent manner, which suggested that these epitopes had an immunoprophylactic potential in a MHC class I‐dependent manner. Moreover, no role of the CD3+ T cell was observed in the IL‐10 production against the selected peptides, and no role was found in disease pathogenesis. Further studies on the role of these synthetic peptides may contribute significantly to developing a polytope vaccine idea towards leishmaniasis.

To evaluate efficacy and safety of amphotericin B in two different doses in the treatment of post kala-azar dermal leishmaniasis (PKDL)

Background Post kala-azar dermal leishmaniasis (PKDL) is a skin disorder that usually occurs among patients with a past history of visceral leishmaniasis (VL). Cases are also reported without a history of VL. There is no satisfactory treatment regimen available at present. We aimed to compare the efficacy and safety of amphotericin B in two different doses (0.5mg/kg vs 1mg/kg) in a prospective randomized trial in 50 PKDL patients. Methods In this open label study 50 patients with PKDL, aged between 5–60 years were randomized in two groups. Group A received amphotericin B in the dose of 0.5 mg/kg in 5% dextrose, daily for 20 infusions for 3 courses at an interval of 15 days between each course and Group B received amphotericin B in the dose of 1mg/kg in 5% dextrose on alternate days, 20 infusions for 3 courses an interval of 15 days between each course and followed up for one year. Results A total of 50 patients were enrolled, 25 in each of group A and group B. Two patients lost to follow up and three patients withdrew consent due to adverse events. The initial cure rate was 92% in group A and 88% in group B by intention to treat analysis and final cure rate by per protocol analysis was 95.65% and 95.45% in group A and group B respectively. Two patients each from either group relapsed. Nephrotoxicity was the most common adverse event occurring in both the groups. Conclusion The lower dose appears to have fewer adverse events however, nephrotoxicity remains a problem in both regimens. The 0.5mg/kg regimen may be considered instead of the higher dosage however safer treatments remain critical for PKDL treatment.

Leishmania donovani phosphoproteins pp41 and pp29 re-establishes host protective immune response in visceral leishmaniasis.

As phospho proteins are reported to be involved in virulence and survival, the ability of Leishmania to inhibit macrophage effector functions may result from a direct interference of leishmanial molecules with macrophage signal transduction pathways. Several such proteins such as pp63, pp41 and pp29 have also been identified as a Th1 stimulatory protein in the Leishmania donovani. In the present study, the immunogenicity of a cocktail of pp63+pp41+pp29 was assessed by estimation of serum antibody titre, nitric oxide(NO) production, estimation of Th1 cytokine(IFN-γ) as well as Th2 cytokines(IL-4), and determination of parasite load in L. donovani infected mice. In the group immunized with antigenic cocktail there was a sharp rise in antibody titer up to Day 20 which reduced considerably by Day 50. Groups of mice vaccinated with pp63, pp41, pp29 and the antigenic cocktail expressed 10-fold, 16-fold, 22-fold and 25-fold increase respectively in NO production by splenocytes. The animal groups immunized with pp63, pp41, pp29 and the antigenic cocktail showed reduced parasite load in the liver and spleen, as well as increased IFN-gamma production in the spleen. Furthermore immunized animals remained with a normal hematological profile, whereas L. donovani in unimmunized mice lead to significant anemia.

Clinicopathological and Immunological Changes in Indian Post Kala-Azar Dermal Leishmaniasis (PKDL) Cases in relation to Treatment: A Retrospective Study

Post-kala-azar dermal leishmaniasis (PKDL) is an important factor in kala-azar transmission; hence its early detection and assessment of effective treatment is very important for disease control. In present study on 60 PKDL cases presented with macular, mixed papulonodular, or erythematous lesions, Leishmania parasites were demonstrated microscopically in 91% of papulonodular and 40% of macular lesions. Cellular infiltrates in skin biopsy imprint smears from lesions were mononuclear cells, 25–300/OIF (oil immersion field), predominantly histiocytes with vacuolation, many lymphocytes, some plasma cells, and Leishmania amastigotes 0–20/OIF. Cases with no demonstrable parasites were diagnosed on the basis of past history of VL, lesions distribution, cytopathological changes, and positive DAT (86.83%). Following antileishmanial treatment with SAG, papulonodular forms of PKDL lesions disappeared clinically but microscopically the mononuclear cells (20–200/OIF) persisted in the dermal lesions. Response observed in macular PKDL lesions was poor which persisted both clinically and cytopathologically. Follow-up of PKDL will assess the effectivity of treatment as either disappearance of lesions or any relapse. Studies on involvement of immunological factors, that is, certain cytokines (IL-10, TGF-β, etc.) and chemokines (macrophage inflammatory protein, MIP 1-α, etc.) in PKDL, may provide insight for any role in the treatment response.