Zijlstra E E, Ali M S, el-Hassan A M, el-Toum I A, Satti M, Ghalib H W, Kager P A
Leishmaniasis Research Group, Medical Research Council, Sudan.
Trans R Soc Trop Med Hyg. 1991 Jul-Aug;85(4):474-6. doi: 10.1016/0035-9203(91)90224-m.
132 patients with suspected kala-azar (visceral leishmaniasis) were included in a prospective study to compare the performance of the direct agglutination test (DAT) with smears of lymph node, bone marrow and splenic aspiration. A titre greater than 1:3200 was considered positive. 67 patients provided positive smears and 65 were smear-negative. Compared with the results obtained from smears, the sensitivity of the DAT was 94% and its specificity 72%. Of 18 patients who were negative by smears but positive by DAT, 3 were treated on strong clinical suspicion of kala-azar and responded well to therapy. One other patient had post-kala-azar dermal leishmaniasis. Of the remaining 14, 8 were tested with the leishmanin skin test; 6 gave a positive result, suggesting past or sub-clinical infection. In 4 smear-positive patients, the DAT was negative; in 2 of these, the test remained negative during 6 months' follow-up. In a sero-epidemiological survey in a camp for displaced people, 30 of 600 sampled individuals gave a positive DAT. Of these, 11 had been treated for kala-azar; 4 others were leishmanin positive. The DAT is a useful screening test (sensitivity 94%; predictive value of a negative test 92%), but it does not differentiate between past kala-azar, sub-clinical infection and active disease.
132例疑似黑热病（内脏利什曼病）患者纳入一项前瞻性研究，以比较直接凝集试验（DAT）与淋巴结、骨髓和脾穿刺涂片检查的性能。滴度大于1:3200被视为阳性。67例患者涂片阳性，65例涂片阴性。与涂片结果相比，DAT的敏感性为94%，特异性为72%。18例涂片阴性但DAT阳性的患者中，3例因强烈临床怀疑黑热病接受治疗，治疗反应良好。另1例患者有黑热病后皮肤利什曼病。其余14例中，8例进行了利什曼原虫皮肤试验；6例结果为阳性，提示既往或亚临床感染。4例涂片阳性患者DAT为阴性；其中2例在6个月随访期间试验仍为阴性。在一个流离失所者营地进行的血清流行病学调查中，600名抽样个体中有30例DAT阳性。其中，11例曾接受黑热病治疗；另外4例利什曼原虫试验阳性。DAT是一种有用的筛查试验（敏感性94%；阴性试验预测值92%），但它不能区分既往黑热病、亚临床感染和活动性疾病。
