Prospective evaluation and comparison of the direct agglutination test and an rK39-antigen-based dipstick test for the diagnosis of suspected kala-azar in Nepal.

摘要: Summary The diagnosis of visceral leishmaniasis (kala-azar) remains difficult in rural endemic areas and practicaland reliable tests are badly needed. Two serological tests, the Direct Agglutination Test (DAT) anrK39-antigen-based dipstick test, were compared to parasitological a group 184 patientspresenting at tertiary care centre south-eastern Nepal with history fever ‡14 days andsplenomegaly; 139 patients had parasitologically proven kala-azar 45 negativeparasitological work-up. rK39 showed sensitivity 97% specificity 71%. TheDAT was up 99% sensitive low cut-off titre (1:400) but its did not exceed 82%even high (1:51 200). Both could be used for screening suspect inendemic areas. However, their use as confirmatory should restricted situations where theproportion among clinical is high. cheaper easierto than DAT widely provided that both performance productionremain stable.keywords leishmaniasis, kala-azar, diagnosis, direct agglutination k39 antigen, dipstick,NepalIntroductionAn estimated 500 000 persons affected by visceralleishmaniasis (VL, also known kala-azar) every yearworldwide. vast majority these cases (90%) occursin poor Sudan, India, Bangladesh, andBrazil (Desjeux 1996). Kala-azar usually fatal if leftuntreated sodium stibogluconate, mostfrequently prescribed first-line therapy generally consideredto relatively safe, can have severe side-effects (Sundaret al. 2000). It is, therefore, prime importance haveaccurate practical diagnostic methods available In most countries, relies onmicroscopic examination lymph nodes, bone marrow orspleen aspirates. Lymph node aspira-tions safe procedures diagnosingkala-azar only 58–64% 70–86%, respectively(WHO 1984; Zijlstra et 1992). Spleen aspiration isgenerally considered gold standard kala-azardiagnosis (Ho 1948; 1992) because ofits (both close 100%).However, it contra-indicated quite number patients, although safer procedure thanthought many physicians. When performed properly,the death rate due bleeding 0.1% reviewedby Kager & Rees (1983). One major drawbacks ofparasitological expertise required fromboth physician perform thelaboratory technician stain read slides accu-rately. This very obtain practiceoutside reference hospitals or specialized treatmentor research centres.Research has focused on development cheap,simple whichcould replace field. TheDirect first described byAllain Kagan (1975) method then adaptedby El Harith (1986, 1988). proved