Sero-epidemiological study of kala-azar in a village of Varanasi district, India.
OBJECTIVE
To evaluate five kala-azar serological tests for field use.


METHODS
Serological survey in Pandit Ka Purva village in Varanasi district, India, using Sia water test, aldehyde test, direct agglutination test (DAT), micro-enzyme-linked immunosorbent assay (ELISA) and dot-ELISA.


RESULTS
The total population of the village was 518, 67 of whom showed typical clinical and parasitological features of kala-azar, including seven who died. The age distribution of kala-azar cases showed significant differences, being highest among the 45-54-year age group. The disease was more prevalent among males. Serum samples were collected from 498 persons (96% of total population) including 67 kala-azar cases and 40 disease controls (malaria, TB, leprosy, typhoid). Ten 10 serum samples from healthy controls living in endemic area were also collected. The test sensitivities were: Sia water test, 85.0%; aldehyde test, 62.7%; DAT, 94.0%; micro-ELISA, 91.0% and dot-ELISA, 97.0%. The test specificities were: Sia water test 92.5%, aldehyde test, 93.2%, DAT, 96.7; micro-ELISA, 97.6% and dot-ELISA, 98.4%.


CONCLUSIONS
The dot-ELISA is highly sensitive and specific, cheap, and easy to interpret with the naked eye, making it a powerful screening test for the surveillance and diagnosis of Indian kala-azar at field level.
Kumar
R
R
Department of Biochemistry, Banaras Hindu University, Varanasi, India. ramesh_1995@sify.com
Pai
K
K
Kumar
P
P
Pandey
H P
HP
Sundar
S
S
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000372:Agglutination Tests / Q000379:methods; D000953:Antigens, Protozoan / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004202:Disinfectants; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005557:Formaldehyde; D006801:Humans; D007194:India / Q000453:epidemiology; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012423:Rural Health; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D012698:Serologic Tests / Q000379:methods; D017678:Sex Distribution; D014867:Water
D000953:Antigens, Protozoan; D004202:Disinfectants; D014867:Water; D005557:Formaldehyde