Fadeel Moustafa Abdel, House Brent L, Wasfy Momtaz M, Klena John D, Habashy Engy E, Said Mayar M, Maksoud Mohamed Abdel, Rahman Bassem Abdel, Pimentel Guillermo
US Naval Medical Research Unit No 3 NAMRU-3, Cairo, Egypt.
J Infect Dev Ctries. 2011 Mar 21;5(3):169-75. doi: 10.3855/jidc.1339.
Typhoid fever is endemic in many parts of the world and represents a major cause of acute febrile illness (AFI). Rapid and accurate laboratory methods for diagnosis of this disease are needed for both patient care and surveillance situations.
Serum samples were collected from AFI patients and used to evaluate the performance of a newly developed ELISA assay that uses a mixture of somatic and flagellar antigens to detect the total antibody response against Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) infection. The levels of Ig isotype response (IgG, IgM and IgA) were also evaluated, and results were compared to those of TUBEX-TF and Typhidot commercial kits.
Of 234 culture-confirmed typhoid patients, the total Ig ELISA diagnosed 93% compared to 71% using Widal test. This sensitivity level (93%) is higher than that observed for the individual Ig ELISAs (IgG 75%; IgM 79%; IgA 57%) and the commercial tests TUBEX-TF (75%), Typhidot IgM (63%) and Typhidot IgG (28%). An agreement of 78% was achieved between the total Ig ELISA and Widal test. The average specificity of the ELISA was 96%. Using ELISA, up to 200 samples can be tested per run with cost per test at US$0.20.
The developed ELISA shows superior sensitivity and specificity, when compared to Widal, TUBEX-TF and Typhidot assays, is more cost effective and allows higher throughput. This method is highly recommended for active surveillance studies or outbreak investigations of typhoid fever.
伤寒热在世界许多地区呈地方性流行，是急性发热性疾病（AFI）的主要病因。无论是患者护理还是监测情况，都需要快速准确的实验室诊断方法来诊断这种疾病。
从AFI患者中采集血清样本，用于评估一种新开发的酶联免疫吸附测定（ELISA）的性能，该测定使用菌体抗原和鞭毛抗原的混合物来检测针对伤寒沙门氏菌肠炎亚种伤寒血清型（伤寒杆菌）感染的总抗体反应。还评估了免疫球蛋白（Ig）同种型反应水平（IgG、IgM和IgA），并将结果与TUBEX-TF和Typhidot商业试剂盒的结果进行比较。
在234例经培养确诊的伤寒患者中，总Ig ELISA诊断出93%的病例，而维达试验诊断出71%的病例。这种灵敏度水平（93%）高于个体Ig ELISA（IgG 75%；IgM 79%；IgA 57%）以及商业检测TUBEX-TF（75%）、Typhidot IgM（63%）和Typhidot IgG（28%）所观察到的灵敏度。总Ig ELISA与维达试验之间的一致性为78%。ELISA的平均特异性为96%。使用ELISA，每次运行可检测多达200个样本，每个检测的成本为0.20美元。
与维达试验、TUBEX-TF和Typhidot检测相比，所开发的ELISA显示出更高的灵敏度和特异性，更具成本效益且通量更高。强烈推荐这种方法用于伤寒热的主动监测研究或疫情调查。
