Evaluation of Loopamp™ Leishmania Detection Kit and Leishmania Antigen ELISA for Post-Elimination Detection and Management of Visceral Leishmaniasis in Bangladesh

Frontiers in Cellular and Infection Microbiology

Ariful Basher¹  Emily R. Adams²  Sophie I. Owen²  Rajashree Chowdhury³  James Baker³  Shomik Maruf³  Md. Utba Rashid³  Faria Hossain³  Rupen Nath³  Debashis Ghosh³  Prakash Ghosh³  Md. Anik Ashfaq Khan⁴  Proggananda Nath⁵  Dinesh Mondal⁶  Md. Sakhawat Hossain⁷  Albert Picado⁸  Israel Cruz⁹  Malcolm S. Duthie^1,10  Fatima Aktar^1,10 

[1] Department of Medicine, Infectious Disease Hospital, Dhaka, Bangladesh;Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom;Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh;Faculty of Medicine, University of Leipzig, Leipzig, Germany;Infectious diseases and Tropical Medicine, Mymensingh Medical College and Hospital, Mymensingh, Bangladesh;Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh;National Kala-azar Elimination Program, CDC, DGHS, Dhaka, Bangladesh;Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland;Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland;International Health Department, National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain;Research, HDT Bio-Corp., Seattle, WA, United States;

关键词: visceral leishmaniasis;    diagnosis;    LAMP;    qPCR;    urine ELISA;    elimination;    diagnostics for VL post-elimination era;   

DOI  :  10.3389/fcimb.2021.670759

来源: Frontiers

【 摘 要 】

With reduced prevalence of visceral leishmaniasis (VL) in the Indian subcontinent (ISC), direct and field deployable diagnostic tests are needed to implement an effective diagnostic and surveillance algorithm for post-elimination VL control. In this regard, here we investigated the diagnostic efficacies of a loop-mediated isothermal amplification (LAMP) assay (Loopamp™ Leishmania Detection Kit, Eiken Chemical CO., Ltd, Japan), a real-time quantitative PCR assay (qPCR) and the Leishmania antigen ELISA (CLIN-TECH, UK) with different sampling techniques and evaluated their prospect to incorporate into post-elimination VL control strategies. Eighty clinically and rK39 rapid diagnostic test confirmed VL cases and 80 endemic healthy controls were enrolled in the study. Peripheral blood and dried blood spots (DBS) were collected from all the participants at the time of diagnosis. DNA was extracted from whole blood (WB) and DBS via silica columns (QIAGEN) and boil & spin (B&S) methods and tested with qPCR and Loopamp. Urine was collected from all participants at the time of diagnosis and was directly subjected to the Leishmania antigen ELISA. 41 patients were followed up and urine samples were collected at day 30 and day 180 after treatment and ELISA was performed. The sensitivities of the Loopamp-WB(B&S) and Loopamp-WB(QIA) were 96.2% (95% CI 89·43-99·22) and 95% (95% CI 87·69-98·62) respectively. The sensitivity of Loopamp-DBS(QIA) was 85% (95% CI 75·26- 92·00). The sensitivities of the qPCR-WB(QIA) and qPCR-DBS(QIA) were 93.8% (95% CI 86·01-97·94) and 72.5% (95% CI 61·38-81·90) respectively. The specificity of all molecular assays was 100%. The sensitivity and specificity of the Leishmania antigen ELISA were 97.5% (95% CI 91·47-99·70) and 91.95% (95% CI 84·12-96·70) respectively. The Leishmania antigen ELISA depicted clinical cure at day 180 in all the followed-up cases. Efficacy and sustainability identify the Loopamp-WB(B&S) and the Leishmania antigen ELISA as promising and minimally invasive VL diagnostic tools to support VL diagnostic and surveillance activities respectively in the post-elimination era.

【 授权许可】

CC BY