Heterogeneity of Leishmania donovani parasites complicates diagnosis of visceral leishmaniasis: comparison of different serological tests in three endemic regions.
Diagnostic tests for visceral leishmaniasis that are based on antigens of a single Leishmania strain can have low diagnostic performance in regions where heterologous parasites predominate. The aim of this study was to investigate and compare the performance of five serological tests, based on different Leishmania antigens, in three endemic countries for visceral leishmaniasis. A total number of 231 sera of symptomatic and asymptomatic cases and controls from three endemic regions of visceral leishmaniasis in East Sudan, North India and South France were evaluated by following serological tests: rKLO8- and rK39 ELISA, DAT (ITMA-DAT) and two rapid tests of rK39 (IT LEISH) and rKE16 (Signal-KA). Overall, rKLO8- and rK39 ELISA were most sensitive in immunocompetent patients from all endemic regions (96-100%) and the sensitivity was reduced to 81.8% in HIV co-infected patients from France. Sera of patients from India demonstrated significantly higher antibody responses to rKLO8 and rK39 compared with sera from Sudan (p<0.0001) and France (p<0.0037). Further, some Indian and Sudanese patients reacted better with rKLO8 than rK39. Sensitivity of DAT (ITMA-DAT) was high in Sudan (94%) and India (92.3%) but low in France being 88.5% and 54.5% for VL and VL/HIV patients, respectively. In contrast, rapid tests displayed high sensitivity only in patients from India (96.2%) but not Sudan (64-88%) and France (73.1-88.5% and 63.6-81.8% in VL and VL/HIV patients, respectively). While the sensitivity varied, all tests showed high specificity in Sudan (96.7-100%) and India (96.6%).Heterogeneity of Leishmania parasites which is common in many endemic regions complicates the diagnosis of visceral leishmaniasis. Therefore, tests based on homologous Leishmania antigens are required for particular endemic regions to detect cases which are difficult to be diagnosed with currently available tests.
Institute for Medical Microbiology and Hygiene, University of Marburg, 35043 Marburg, Germany; Biomedical Research Laboratory, Ahfad University for Women, P.O. Box 167, Omdurman, Sudan; Faculty of Medical Laboratory Sciences, Sudan International University, Khartoum, Sudan.
Elfadil
E
Abass
Institute for Medical Microbiology and Hygiene, University of Marburg, 35043 Marburg, Germany.
Cholho
C
Kang
Department for Parasitology and Parasitic Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia.
Franjo
F
Martinkovic
Department of Nursing, University Tiradentes (UNIT), Campus Farolândia, CEP 49.032-490, Aracaju, Sergipe- Brazil.
Saul J
SJ
Semião-Santos
Institute of Medical Sciences, Banaras Hindu University, Varanasi-221 005 UP, India.
Shyam
S
Sundar
Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Peter
P
Walden
UMR MD3 Aix-Marseille University, Marseille, France.
Renaud
R
Piarroux
Biomedical Research Laboratory, Ahfad University for Women, P.O. Box 167, Omdurman, Sudan.
Abdallah
A
El Harith
Institute for Medical Microbiology and Hygiene, University of Marburg, 35043 Marburg, Germany.
Michael
M
Lohoff
Institute for Medical Microbiology and Hygiene, University of Marburg, 35043 Marburg, Germany.
Ulrich
U
Steinhoff
D000953:Antigens, Protozoan / Q000097:blood* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015658:HIV Infections / Q000150:complications; D006801:Humans; D007118:Immunoassay; D007893:Leishmania donovani / Q000502:physiology*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity
D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins; C079253:K39 antigen, Leishmania