REEVALUATION OF THE WIDAL AGGLUTINATION-TEST IN RESPONSE TO THE CHANGING PATTERN OF TYPHOID-FEVER IN THE HIGHLANDS OF PAPUA-NEW-GUINEA
REEVALUATION OF THE WIDAL AGGLUTINATION-TEST IN RESPONSE TO THE CHANGING PATTERN OF TYPHOID-FEVER IN THE HIGHLANDS OF PAPUA-NEW-GUINEA
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DOI：
10.1016/0001-706x(94)90071-x
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发表时间：
1994-09-01
期刊：
影响因子：
2.7
通讯作者：
SUVE, N
中科院分区：
文献类型：
--
作者：
CLEGG, A;PASSEY, M;SUVE, N
1992年，巴布亚新几内亚决定重新评估维达尔玻片凝集试验作为伤寒的快速诊断试验。这是对使用大于或等于 40 的 O 截止滴度进行的 Widal 玻片凝集假阳性数量明显增加的反应，该滴度先前在 1987 年被证明是合适的。重新评估的结果表明，使用大于或等于 40 的诊断截止滴度的 Widal 测试缺乏特异性，不再适合该人群。建议使用大于或等于 160 的新 O 抗体滴度作为巴布亚新几内亚伤寒的诊断滴度。在初次评估和重新评估之间的五年期间，维达尔玻片凝集试验的特异性下降是由于社区伤寒模式的变化导致总体人群抗体水平升高。 1987 年之前，伤寒是零星、孤立的疫情，大多数生活在巴布亚新几内亚高地的人在免疫学上都是幼稚的。到 1992 年，伤寒已成为一种公认的地方病，更多的人接触了伤寒沙门氏菌，并因此产生了抗体。我们已经能够清楚地证明社区免疫状态的显着变化，其中维达尔管O凝集滴度为40或更高的健康个体的比例在短短五年内从0上升到56%。影响维达尔凝集试验在人群中的有效性的因素包括伤寒的流行、对伤寒的免疫反应、一般人群对伤寒沙门氏菌的抗体水平以及选择适当的诊断临界滴度的能力。尽管其有效性会随时间和地点的不同而变化，但维达尔凝集试验在适当的情况下仍然是一种有用的诊断试验。
In 1992 it was decided to re-evaluate the Widal slide agglutination test as a rapid diagnostic test for typhoid fever in Papua New Guinea. This was in response to an apparent increase in the number of false positive Widal slide agglutinations occurring using an O cut-off titre greater than or equal to 40 which was previously shown to be appropriate in 1987. The results of the re-evaluation indicated that the Widal test using a diagnostic cut-off titre of greater than or equal to 40 lacked specificity and was no longer appropriate for this population. A new O antibody titre of greater than or equal to 160 was recommended as a diagnostic titre for typhoid fever in PNG. The fall in the specificity of the Widal slide agglutination test over the five-year period between the initial assessment and the re-evaluation is due to an increase in general population antibody levels caused by the changing pattern of typhoid in the community. Before 1987 typhoid fever occurred as sporadic, isolated outbreaks and most people living in the highlands of PNG were immunologically naive. By 1992 typhoid fever had become a well-established endemic disease and many more people had been exposed to Salmonella typhi and as a result developed antibodies. We have been able to demonstrate clearly a remarkable change in the immune status of the community, in which the proportion of healthy individuals with a Widal tube O agglutination titre of 40 or more rose from 0 to 56% in the short span of five years. Factors influencing the usefulness of the Widal agglutination test in a population include the endemicity of typhoid fever, the immune response to typhoid, general population antibody levels to Salmonella typhi and the ability to select an appropriate diagnostic cut-off titre. Though its usefulness will vary with time and place, the Widal agglutination test remains a useful diagnostic test under appropriate circumstances.