School of Public Health and Primary Care, College of Medicine, Nursing and Health Sciences, Fiji National University, Suva, Fiji.
Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia.
Am J Trop Med Hyg. 2021 Nov 29;106(2):543-549. doi: 10.4269/ajtmh.21-0771.
Typhoid is an endemic in Fiji with increases observed since the early 2000s and frequent outbreaks reported. We assessed the diagnostic accuracy of currently available typhoid rapid diagnostic tests (RDTs) (TUBEX, Typhidot Rapid, and Test-It assay) to establish their performance against blood culture in Fiji and to examine their suitability for rapid typhoid outbreak identification. The performance of RDTs was assessed in the public health reference laboratory in Suva, Fiji, according to the manufacturers' instructions. A simulation was used to examine the potential use of RDTs for attribution of a febrile illness outbreak to typhoid. For the diagnostic evaluation, 179 patients were included; 49 had blood culture-confirmed typhoid, 76 had fever as a result of non-typhoid etiologies, and 54 were age-matched community controls. The median (interquartile range) age was 29 (20-46) years. Of the participants, 92 (51.4%) were male and 131 (73.2%) were indigenous Fijians. The sensitivities of the tests were 77.6% for TUBEX, 75.5% for Typhidot Rapid, and 57.1% for Test-It assay. The Test-It assay had the highest specificity of 93.4%, followed by Typhidot Rapid 85.5% and TUBEX 60.5%. Typhidot Rapid had the best performance in the simulation for attribution of a febrile illness outbreak to typhoid. Typhoid RDTs performed suboptimally for individual patient diagnosis due to low sensitivity and variable specificity. We demonstrate that RDTs could be useful in the field for rapid attribution of febrile illness outbreaks to typhoid. Typhidot Rapid had the best combination of sensitivity, specificity, positive and negative predictive values, cost, and ease of use for this purpose.
在斐济，伤寒是地方性疾病，自 21 世纪初以来发病率不断上升，且经常爆发。我们评估了目前可用的伤寒快速诊断检测（RDT）（TUBEX、Typhidot Rapid 和 Test-It 检测）的诊断准确性，以确定它们在斐济与血培养的对比结果，并检验它们在快速伤寒暴发识别方面的适用性。在斐济苏瓦的公共卫生参考实验室，按照制造商的说明评估 RDT 的性能。通过模拟检验 RDT 用于归因发热性疾病暴发为伤寒的潜在用途。为了进行诊断评估，纳入了 179 名患者；49 名患者的血培养证实为伤寒，76 名患者因非伤寒病因发热，54 名患者为年龄匹配的社区对照者。参与者的中位（四分位间距）年龄为 29（20-46）岁。其中 92 名（51.4%）为男性，131 名（73.2%）为斐济原住民。三种检测方法的灵敏度分别为 TUBEX 77.6%、Typhidot Rapid 75.5%和 Test-It 检测 57.1%。Test-It 检测的特异性最高，为 93.4%，其次是 Typhidot Rapid 85.5%和 TUBEX 60.5%。在归因发热性疾病暴发为伤寒的模拟中，Typhidot Rapid 的表现最佳。由于灵敏度低和特异性变化，伤寒 RDT 在个体患者诊断中的表现不理想。我们证明 RDT 可在现场用于快速归因发热性疾病暴发为伤寒。就该目的而言，Typhidot Rapid 在灵敏度、特异性、阳性和阴性预测值、成本和易用性方面具有最佳的综合性能。
