Application of CL Detect™ rapid test for diagnosis and liposomal amphotericin B for treatment of cutaneous leishmaniasis: A retrospective analysis from a tertiary care centre in a non-endemic area in India.

Background Increasing urbanisation has led to the occurrence of cutaneous leishmaniasis (CL) in new areas, which was otherwise localised to endemic areas. Healthcare workers should be made aware of this entity to ensure clinical suspicion of CL and investigations needed to confirm CL. The article describes patients seen at a tertiary hospital in Delhi. Aims To establish the utility of the CL Detect Rapid test as a diagnostic tool and the efficacy of Liposomal Amphotericin B (LAmB) for the complete cure of CL patients. Methods Data of patients of CL (n = 16) was retrospectively analysed concerning diagnosis and treatment. Diagnosis rested on histopathology, real-time PCR, and CL Detect Rapid Test. Speciation of the parasite was based on the Internal transcribed spacer-I gene. Patients were treated with LAmB (i.v., 5 mg/kg up to three doses, five days apart). Results A positivity of 81.3% (95%CI, 54.4-96) was observed for CL Detect Rapid test in comparison with 100% (95%CI, 79.4-100.0) for real-time PCR and 43.8% (95%CI, 19.8-70.1) for microscopy/histopathological examination. L. tropica was the infective species in all cases. All the patients treated with LAmB responded to treatment, and 9/10 patients demonstrated complete regression of lesions, while one was lost to follow-up. Limitations It is a retrospective study, and the data includes only confirmed cases of CL at a single centre. Conclusion This study highlights the utility of CL Detect as a promising diagnostic tool and the efficacy of LAmB for the complete cure of CL.

Development of a novel loop-mediated isothermal amplification assay for rapid detection of Mycobacterium leprae in clinical samples.

BACKGROUND: Sensitive and definitive diagnostic tests are required for timely treatment of leprosy and to control its transmission. AIM: In the present study, we report the development of loop-mediated isothermal amplification assay using six primers targeting the RLEP gene sequence uniquely present in Mycobacterium leprae. METHODS: Tissue punch samples (n = 50) and slit aspirates (n = 50) from confirmed cases of leprosy (M. leprae positive by quantitative polymerase chain reaction), reporting at the Department of Dermatology, Safdarjung Hospital, New Delhi, were analyzed using newly developed closed tube loop-mediated isothermal amplification assay. The sensitivity and specificity; positive predictive value, negative predictive value and accuracy were calculated using MedCalc statistical software. RESULTS: The loop-mediated isothermal amplification assay specifically amplified M. leprae genomic DNA with an analytical sensitivity of 100 fg. About 47 Out of the 50 quantitative polymerase chain reactions confirmed M. leprae positive tissue samples, 47 were positive by loop-mediated isothermal amplification assay (sensitivity 94%; 95% confidence interval 83.5%-98.8%) while only 31/50 were positive by histopathology (sensitivity 62%; 95% confidence interval 47.2%-75.4%) . Using slit aspirate samples of these 50 patients, 42 were positive by both quantitative polymerase chain reaction and loop-mediated isothermal amplification assay (sensitivity 84%; 95% confidence interval 70.9%-92.8%) while only 23/50 (sensitivity 46%; 95% confidence interval 31.8%-60.7%) were positive by microscopy. LIMITATIONS: In the present study, the leprosy patient cohort was not uniform, as it comprised a lower number of paucibacillary cases (22%) compared to multibacillary (78%) cases. CONCLUSION: Loop-mediated isothermal amplification assay established here provides a rapid and accurate diagnostic test for leprosy in terms of sensitivity and specificity. The assay is simple to perform in comparison with other molecular techniques (polymerase chain reaction/quantitative polymerase chain reaction) and has potential for field applicability.

Rapid Multiplex Loop-Mediated Isothermal Amplification (m-LAMP) Assay for Differential Diagnosis of Leprosy and Post-Kala-Azar Dermal Leishmaniasis.

Leprosy and post-kala-azar dermal leishmaniasis (PKDL) are co-endemic neglected tropical diseases often misdiagnosed because of close resemblance in their clinical manifestations. The test that aids in differential diagnosis of leprosy and PKDL would be useful in endemic areas. Here, we report development of a multiplex loop-mediated isothermal amplification (m-LAMP) assay for differential detection of Mycobacterium leprae and Leishmania donovani using a real-time fluorometer. The m-LAMP assay was rapid with a mean amplification time of 15 minutes, and analytical sensitivity of 1 fg for L. donovani and 100 fg for M. leprae. The distinct mean Tm values for M. leprae and L. donovani allowed differentiation of the two organisms in the m-LAMP assay. Diagnostic sensitivity of the assay was evaluated by using confirmed cases of leprosy (n = 40) and PKDL (n = 40) (tissue and slit aspirate samples). All the leprosy and PKDL samples used in this study were positive by organism-specific QPCR and loop-mediated isothermal amplification assays. The diagnostic sensitivity of the m-LAMP assay was 100% (95% CI: 91.2-100.0%) for detecting PKDL and 95% for leprosy (95% CI: 83.1-99.4%). Our m-LAMP assay was successfully used to detect both M. leprae and L. donovani in a patient coinfected with leprosy and macular PKDL. The m-LAMP assay is rapid, accurate, and applicable for differential diagnosis of leprosy versus PKDL, especially in endemic areas.

Revisiting the role of the slit-skin smear in the diagnosis of Indian post-kala-azar dermal leishmaniasis.

BACKGROUND: Post kala azar dermal leishmaniasis (PKDL) is a neglected dermatosis that develops as a sequel to kala azar after apparent complete treatment. Being a non life threatening condition, patients often delay treatment thereby maintaining a reservoir of infection. The diagnosis of PKDL rests on the demonstration of the parasite in tissue smears, immune diagnosis by detection of parasite antigen or antibody in blood, or detection and quantitation of parasite DNA in tissue specimens. Sophisticated molecular tests are not only expensive but also need skilled hands and expensive equipment. To be useful, diagnostic methods must be accurate, simple and affordable for the population for which they are intended. AIMS: This study was designed to assess functionality and operational feasibility of slit-skin smear examination. METHODS: Sensitivity and specificity was evaluated by performing slit-skin smear and histo-pathological examination in 46 PKDL patients and the results were compared with the parasite load in both the slit aspirate and tissue biopsy specimens by performing quantitative Real-time PCR (Q-PCR). RESULTS: The slit-skin smear examination was more sensitive than tissue biopsy microscopy. The parasite loads significantly differed among various types of clinical lesions (P < 0.05). The threshold of parasite load for detection by SSS microscopy was 4 parasites/µl in slit aspirate and 60 parasites/µg tissue DNA in tissue biopsy while that for tissue microscopy was 63 parasites/µl and 502 parasites/µg tissue DNA respectively. As detection of Leishmania donovani bodies may be challenging in inexperienced hands, the microscopic structure of these has been detailed along with a comprehensive discussion of pre analytical, analytical and post analytical variables affecting its identification. To facilitate the diagnosis of PKDL, some scenarios have been suggested taking into consideration the clinical, epidemiological, immunological and microscopic aspects. CONCLUSION: Such evidence based medicine helps minimize intuition, systematize clinical experience and provides a diagnostic rationale as sufficient grounds for a clinical decision.

Unresponsive cutaneous leishmaniasis and HIV co-infection: report of three cases.

Cutaneous leishmaniasis (CL) is a vector borne disease caused by various species of Leishmania parasite. CL is endemic in the Thar desert of Rajasthan state and Himachal Pradesh in India. Immune suppression caused by human immunodeficiency virus (HIV) infection is associated with atypical clinical presentation of CL which responds poorly to the standard treatment and causes frequent relapses. We are reporting three cases of localized and disseminated CL due to Leishmania tropica which failed to respond to conventional intralesional/intramuscular sodium stibogluconate (SSG) injections. Initially, we did not think of HIV infection because CL is endemic in this region. When patients did not respond to SSG injections, we performed enzyme-linked immunosorbent assay (ELISA) tests for HIV and they turned out to be HIV positive. Our report showed that CL is emerging as an opportunistic infection associated with HIV/AIDS and may be the first manifestation in HIV positive patients in an endemic area.

A retrospective study of intravenous sodium stibogluconate alone and in combinations with allopurinol, rifampicin, and an immunomodulator in the treatment of Indian post-kala-azar dermal leishmaniasis.

BACKGROUND AND AIMS: A retrospective analysis of treatment outcome using recommended dose of sodium stibogluconate (SSG) alone and in combination with other antileishmanial drugs in adults with post-kala-azar dermal leishmaniasis (PKDL) attending as outpatients. METHODS: A total of 61 patients seen over ten years were included in the report. All had polymorphic lesions. Diagnosis was based on clinical picture, hailing from kala-azar (KA) endemic area, exclusion of other dermatoses, histopathology, and therapeutic response. Patients were distributed into two groups: Group I (n = 32), where SSG was given intravenously; in Group II (n = 29), they were allocated to one of four categories using SSG in combination with other drugs. In the first category, SSG was given along with allopurinol (n = 10); in second with rifampicin (n = 6); and in third with both allopurinol and rifampicin (n = 5). In the fourth category, SSG was administered with an immunomodulator (n = 8), Mw vaccine, known to enhance host Th1 response. RESULTS: Only 12 out of 61 patients completed treatment till histopathologic evidence of cure, five in Group I and seven in Group II, no patient being from third category. None had taken SSG without interruptions. Time taken for papulonodules to subside was similar in both groups, but erythema and induration subsided earlier in Group II. Group I patients attained cure after 120 injections while in Group II it took 95 injections in SSG + allopurinol and Mw vaccine categories respectively, and 110 with SSG + rifampicin. Nevertheless this was insufficient to facilitate compliance. Poor performance and high dropouts related to long duration of therapy, thrombophlebitis, difficulty in accessing veins, disabling rheumatic side-effects and practical problems. Liver, renal and pancreatic functions and ECG remained normal. CONCLUSION: No major advantage was obtained using allopurinol, rifampicin or Mw vaccine along with SSG as compared to SSG alone.

Immune response following miltefosine therapy in a patient with post-kala-azar dermal leishmaniasis.

We report a case of post-kala-azar dermal leishmaniasis in which real-time PCR was exploited to measure changes in cytokine transcripts in lesion tissue before and after oral miltefosine treatment. Unlike antimonial therapy elevated levels of IFNgamma transcripts were noted, whereas TNFalpha, IL-10 and transforming growth factor-beta declined similar to that observed after therapy with antimonials. A significant increase in IFNgamma and CD40 levels seen after miltefosine therapy could enhance parasite clearance. The patient remained normal after 18 months of follow-up.