Investigator(s)
| WHO Technical Officer |
Shahwar Kazmi WHO Country Office for India Shahwar Kazmi 
|
| Principal Investigator |
Rishikesh Kumar ICMR-RMRIMS, Agamkuan, Patna – 800007, India Rishikesh Kumar
|
Title(s) and abstract
| Scientific title | Validation of the quantitative buffy coat test and evaluation of venous blood buffy coat specimens through nucleic acid-based amplification tests for the diagnosis of visceral and dermal leishmaniasis. |
| Public title | Validation of the quantitative buffy coat test and evaluation of venous blood buffy coat specimens through nucleic acid-based amplification tests for the diagnosis of visceral and dermal leishmaniasis. |
| Background | This study aims to validate the quantitative buffy coat (QBC) test and assess the efficacy of venous blood buffy coat specimens in nucleic acid-based amplification tests (NAATs) for diagnosing visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL) in Bihar, India. Laboratory confirmation of VL and PKDL typically relies on microscopic, serologic, or NAAT methods utilizing specimens such as bone marrow or skin biopsies. While buffy coat specimens are popular for VL diagnosis in Bangladesh, their use in India remains under-evaluated. The study posits that buffy coat smear microscopy is a minimally invasive and accurate diagnostic method. By concentrating the leishmanial parasites through buffy coat preparation, the likelihood of detection increases. Enhanced diagnostic accuracy could significantly improve clinical outcomes and disease surveillance in endemic areas, making these techniques more accessible and affordable in resource-limited settings. |
| Objectives | To validate the quantitative venous blood buffy coat (QBC) test for the diagnosis of visceral and dermal leishmaniasis in comparison to an rK39 RDT, microscopic examinations and nucleic acid amplification tests of a splenic/bone marrow aspirate or skin slit specimen. To evaluate the venous blood buffy coat specimen against a splenic/bone marrow aspirate or skin slit specimen in microscopic and nucleic acid-based amplification tests for diagnosing visceral and dermal leishmaniasis. |
| Study Methods | This cross-sectional study will be conducted from March 2025 to February 2026 at the ICMR-RMRIMS in Patna and MRHRU-Kurhani, Muzaffarpur, Bihar, focusing on diagnosing visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). Participants will be individuals of any age or gender presenting with clinical symptoms suggestive of VL or PKDL, who voluntarily consent to join the study. Exclusions include those undergoing recent antileishmanial therapy. A single collection of venous blood will be taken from each participant for buffy coat isolation, genomic DNA extraction, and QBC testing. Laboratory tests will include the QBC test, buffy coat microscopy, and qPCR, with results being analyzed by trained microscopists. Data on demographic and clinical features, blood counts, and test results will be collected. The study aims to enroll approximately 75 participants (50 VL and 25 PKDL). Statistical analyses will evaluate diagnostic performance, using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) as metrics. Additionally, Receiver Operating Characteristic (ROC) curves and Kappa statistics will be calculated to assess the accuracy and agreement of the diagnostic tests. This study seeks to improve diagnostic accuracy for VL and PKDL, enhancing clinical outcomes and disease surveillance in endemic regions. |
| Expected outcomes and use of results | This study evaluates the diagnostic performance of three tests—QBC test, buffy coat smear, and qPCR—for detecting visceral and dermal leishmaniasis. To assess their effectiveness, microscopic evaluations of bone marrow or splenic aspirates and skin slit smears will act as the comparative benchmark. The analysis will focus on various statistical measures for each subtype of leishmaniasis, including: Sensitivity: This reflects the proportion of actual positive cases correctly identified by the test, also known as the True Positive Rate. Specificity: This measures the accuracy in identifying true negative cases. Positive Predictive Value (PPV): This indicates the probability that individuals identified as positive actually have the disease. Negative Predictive Value (NPV): This denotes the probability that individuals identified as negative do not have the disease. Overall, the study aims to provide valuable insights into the strengths and limitations of each diagnostic method, enhancing our understanding of their utility in accurately distinguishing between visceral and dermal leishmaniasis. The findings will contribute to improving diagnostic practices for these conditions. |
| Keywords | QBC, Visceral Leishmaniasis, PKDL |
Research Details
| Student research | No |
| Start Date | 11-Mar-2025 |
| End Date | 15-Dec-2025 |
| Key Implementing Institution | Rajendra Memorial Research Institute of Medical Science (ICMR Regional Institute) |
| Multi-country research | No |
| Nationwide research | No |
| India | |
| Research Domain(s) | Communicable Disease Research |
| Research field(s) | Infectious Disease |
| Involves human subjects | Yes |
| Operational Research | |
| Data Collection | Primary data |
| Proposal reviewed by other Committee | No |