Terán-Angel Guillermo, Schallig Henk, Zerpa Olga, Rodríguez Vestalia, Ulrich Marian, Cabrera Maira
Instituto de Biomedicina, Universidad Central de Venezuela, San José, Caracas, Venezuela.
Biomedica. 2007 Sep;27(3):447-53.
Visceral leishmaniasis is the most severe clinical form of leishmaniasis and is often fatal without proper treatment. Therefore, early and accurate diagnosis is important, but often difficult in endemic areas.
The aim was to evaluate a direct agglutination test as a potential visceral leishmaniasis diagnostic method in endemic areas of Venezuela.
The performance of the direct agglutination test, based on freeze-dried Leishmania donovani antigen was evaluated under laboratory conditions using serum samples of humans and dogs from several Venezuelan visceral leishmaniasis endemic areas: Nueva Esparta (Margarita Island), Lara, Anzoátegui and Trujillo Status. The study included confirmed visceral leishmaniasis patients (n=30), visceral leishmaniasis suspected subjects (n=4), healthy controls (n=19) and patients with other confirmed diseases (n=20). In addition, 24 serum samples from dogs with confirmed visceral leishmaniasis and 18 healthy control dogs were tested.
All serum samples of visceral leishmaniasis patients, either active or recovered, were positive. They showed anti-L. donovani titers above 1:1600. Three out of four suspected visceral leishmaniasis cases were also positive, while serum samples from endemic controls and patients with other diseases had titers lower than 1:800. A sensitivity of 100% was obtained for all threshold levels under consideration and 100% specificity at the threshold titer of 1:800 (95% confidence interval: 91-100%). A 93% sensitivity (95% confidence interval: 76-99%) was observed in dog samples, with 100% specificity (95% confidence interval: 79-100%) at the threshold titer of 1:200.
The direct agglutination test seems suitable for use in epidemiological studies and for serological diagnosis of human visceral leishmaniasis and canine visceral leishmaniasis.
内脏利什曼病是利什曼病最严重的临床形式，若未经适当治疗往往会致命。因此，早期准确诊断很重要，但在流行地区往往很难做到。
旨在评估直接凝集试验作为委内瑞拉流行地区潜在的内脏利什曼病诊断方法。
在实验室条件下，使用来自委内瑞拉几个内脏利什曼病流行地区（新埃斯帕塔州[玛格丽塔岛]、拉腊州、安索阿特吉州和特鲁希略州）的人类和犬类血清样本，对基于冻干杜氏利什曼原虫抗原的直接凝集试验性能进行评估。该研究纳入了确诊的内脏利什曼病患者（n = 30）、疑似内脏利什曼病受试者（n = 4）、健康对照者（n = 19）以及患有其他确诊疾病的患者（n = 20）。此外，还检测了24份来自确诊内脏利什曼病犬的血清样本和18份健康对照犬的血清样本。
所有活动期或康复期内脏利什曼病患者的血清样本均呈阳性。它们显示出抗杜氏利什曼原虫滴度高于1:1600。4例疑似内脏利什曼病病例中有3例也呈阳性，而流行地区对照者和患有其他疾病患者的血清样本滴度低于1:800。对于所考虑的所有阈值水平，灵敏度均为100%，在滴度阈值为1:800时特异性为100%（95%置信区间：91 - 100%）。在犬类样本中观察到灵敏度为93%（95%置信区间：76 - 99%），在滴度阈值为1:200时特异性为100%（95%置信区间：79 - 100%）。
直接凝集试验似乎适用于流行病学研究以及人类内脏利什曼病和犬类内脏利什曼病的血清学诊断。
