Applicability of direct agglutination test (DAT) at a rural health setting in Bangladesh and feasibility of local antigen production.
As part of a large-scale sero-epidemiological survey on visceral leishmaniasis (VL) carried out in Mymensingh district of Bangladesh, applicability of DAT was assessed at the level of a rural health setting in Trishal (upazila) subdistrict. Despite the relatively less optimal conditions encountered, 5854 inhabitants from 7 villages appendant to Trishal were assessed for VL. The demographic distribution for sero-positivity obtained at the rural setting was comparable to that found by DAT as executed at the central laboratory (IEDC&R, Dhaka) on 9619 inhabitants from the same upazila. The overall sero-prevalence rate was 4.4% compared to 3.7% obtained in the population assessed at the central laboratory. In either study, similar VL prevalence rates of 2.1% were obtained in the male populations. Irrespective of sex, younger population (< 20 years) in both studies appeared to have higher VL incidence rate (2.3% and 2.6%) than others of 21- > or = 90 years (1.4% and 1.8%). Local production of DAT antigen employing an authochtonus L. donovani isolate was attempted at the central laboratory (IEDC&R) in Dhaka. By comparison with the reference antigen, titres obtained in all 33 VL sera tested were equally higher (1:6400- > or =: 51200) than in 35 out of 38 negative controls (< or = 1:400-1:1600). A comparable level of reactivity was also obtained in 53 VL and 52 negative control sera using a well characterized L. donovani strain (MHOM/IN/80/D88) from India. However, unlike the reference strain, titres obtained in 7 endemic controls were significantly higher with the authochtonous and homologous antigen (1:3200 - 1:6400) than with the reference (1:100 - 1:1600). The results signify the advantage of employing indigenous L. donovani isolates to further improve DAT sensitivity for detection of early and sub-clinical VL.
Chowdhury
M S
MS
Institute of Epidemiology Disease Control & Research (IEDC&R), Mohakhali, Dhaka-Bangladesh.
al Masum
A
A
al Karim
E
E
Semiáo-Santos
S
S
Rahman
K M
KM
Ar-Rashid
H
H
el Harith
A
A
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000372:Agglutination Tests / Q000379:methods*; D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood*; D001459:Bangladesh / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007223:Infant; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000097:blood* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D012423:Rural Health; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D000953:Antigens, Protozoan