Detection of asymptomatic Leishmania infection in Bangladesh by antibody and antigen diagnostic tools shows an association with post–kala-azar dermal leishmaniasis (PKDL) patients

Parasites & Vectors

Emily R. Adams¹  Sophie I. Owen¹  Albert Picado²  Isra Cruz³  Chris Jewell⁴  Faria Hossain⁵  Rajashree Chowdhury⁵  Md. Sakhawat Hossain⁵  Dinesh Mondal⁵  Prakash Ghosh⁵ 

[1]Department of Tropical Disease Biology, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK

[2]Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland

[3]Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland

[4]National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain

[5]Lancaster Medical School, Lancaster University, Lancaster, UK

[6]Nutrition and Clinical Services Division, International Centre for Diarrhoeal Diseases Research (icddr,b), Dhaka, Bangladesh

关键词: Visceral leishmaniasis;    Elimination;    Leishmania;    Diagnostics;    Leishmania;    qPCR;   

DOI  :  10.1186/s13071-021-04622-8

来源: Springer

【 摘 要 】

BackgroundAsymptomatic Leishmania infections outnumber clinical infections on the Indian subcontinent (ISC), where disease reservoirs are anthroponotic. Diagnostics which detect active asymptomatic infection, which are suitable for monitoring and surveillance, may be of benefit to the visceral leishmaniasis (VL) elimination campaign on the ISC.MethodsQuantitative polymerase chain reaction (qPCR), loop-mediated isothermal amplification (LAMP), and the direct agglutination test (DAT) were carried out on blood samples, and the Leishmania antigen ELISA was carried out on urine samples collected from 720 household and neighbouring contacts of 276 VL and post–kala-azar dermal leishmaniasis (PKDL) index cases, with no symptoms or history of VL or PKDL, in endemic regions of Bangladesh between September 2016 and March 2018.ResultsOf the 720 contacts of index cases, asymptomatic infection was detected in 69 (9.6%) participants by a combination of qPCR (1.0%), LAMP (2.1%), DAT (3.9%), and Leishmania antigen ELISA (3.3%). Only one (0.1%) participant was detected positive by all four diagnostic tests. Poor agreement between tests was calculated using Cohen’s kappa (κ) statistics; however, the Leishmania antigen ELISA and DAT in combination captured all participants as positive by more than one test. We find evidence for a moderately strong association between the index case being a PKDL case (OR 1.94, p = 0.009), specifically macular PKDL (OR 2.12, p = 0.004), and being positive for at least one of the four tests.ConclusionsLeishmania antigen ELISA on urine detects active asymptomatic infection, requires a non-invasive sample, and therefore may be of benefit for monitoring transmission and surveillance in an elimination setting in combination with serology. Development of an antigen detection test in a rapid diagnostic test (RDT) format would be of benefit to the elimination campaign.Graphical Abstract

【 授权许可】

CC BY