rK39 enzyme-linked immunosorbent assay for diagnosis of Leishmania donovani infection.
The rK39 enzyme-linked immunosorbent assay (ELISA) was compared with the direct agglutination test (DAT) for Leishmania donovani infection in the Sudan. rK39 ELISA proved more sensitive than DAT in diagnosis of kala-azar (93 and 80%, respectively); both tests may remain positive up to 24 months after treatment. For patients with post-kala-azar dermal leishmaniasis and individuals with subclinical infection, rK39 ELISA performed as well as DAT but could detect infection 6 months earlier in approximately 40% of patients. Conversion in DAT and rK39 ELISA also occurred in leishmanin skin test (LST)-positive individuals, suggesting active parasite replication (rK39 is an amastigote antigen) in these presumably immune individuals. In contrast to DAT, rK39 ELISA also detected infection in randomly selected LST-positive individuals (in four of six) and endemicity (LST-negative) controls (in one of five). rK39 ELISA appears more sensitive than DAT and may prove an important tool in epidemiological studies.
Zijlstra
E E
EE
Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.
Daifalla
N S
NS
Kager
P A
PA
Khalil
E A
EA
El-Hassan
A M
AM
Reed
S G
SG
Ghalib
H W
HW
D000293:Adolescent; D000328:Adult; D000372:Agglutination Tests / Q000379:methods; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D008875:Middle Aged; D015800:Protozoan Proteins / Q000276:immunology*; D016036:Seroepidemiologic Studies; D013397:Sudan / Q000453:epidemiology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; C079253:K39 antigen, Leishmania