Department of International Health Program in Global Disease Epidemiology and Control, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Trop Med Int Health. 2014 Mar;19(3):301-307. doi: 10.1111/tmi.12252. Epub 2014 Jan 9.
To evaluate the specificity of the Crystal VC dipstick test for detecting cholera.
We compared direct testing using the Crystal VC dipstick test and testing after enrichment for 6 h in alkaline peptone water (APW) to bacterial culture as the gold standard. Samples positive by dipstick but negative by culture were also tested using PCR.
Stool was collected from 125 patients. The overall specificities of the direct testing and testing after 6-h enrichment in APW compared to bacterial culture were 91.8% and 98.4% (P = 0.125), respectively, and the sensitivities were 65.6% and 75.0% (P = 0.07), respectively.
The increase in the sensitivity of the Crystal VC kit with the use of the 6-h enrichment step in APW compared to direct testing was marginally significant. The Crystal VC dipstick had a much higher specificity than previously reported (91-98%). Therefore, this method might be a promising screening tool for cholera outbreak surveillance in resource-limited settings where elimination of false-positive results is critical.
评估 Crystal VC 检测棒试验检测霍乱的特异性。
我们比较了直接使用 Crystal VC 检测棒试验检测与在碱性蛋白胨水（APW）中富集 6 小时后检测，以细菌培养为金标准。检测棒阳性但培养阴性的样本也使用 PCR 进行检测。
从 125 名患者中采集了粪便样本。与细菌培养相比，直接检测和在 APW 中富集 6 小时后的检测的总体特异性分别为 91.8%和 98.4%（P = 0.125），敏感性分别为 65.6%和 75.0%（P = 0.07）。
与直接检测相比，在 APW 中使用 6 小时富集步骤可略微提高 Crystal VC 试剂盒的敏感性。Crystal VC 检测棒的特异性明显高于先前报道（91-98%）。因此，这种方法可能是资源有限环境中霍乱暴发监测的有前途的筛查工具，在这些环境中消除假阳性结果至关重要。
