Evaluation of a nanophosphor lateral-flow assay for self-testing for herpes simplex virus type 2 seropositivity

Herpes Simplex Virus Type 2 (HSV-2) is a common human pathogen that causes life-long illness. The US prevalence of HSV-2 infection is 11.9% for individuals between 15 and 49 years of age. Individuals with HSV-2 infection are more likely to contract and spread other sexually-transmitted infections. Eighty percent of individuals with HSV-2 are unaware of their infection, in part because of the social stigma associated with in-clinic testing for sexually-transmitted infections. We conducted an initial evaluation of a prototype smartphone-based serological lateral-flow immunoassay (LFA) for HSV-2 infection that uses strontium aluminate persistent luminescent nanoparticles (nanophosphors) as reporters. When applied to a test panel of 21 human plasma/serum samples varying in anti-HSV titer, the nanophosphor HSV-2 LFA had 96.7% sensitivity and 100% specificity for detection of HSV-2 infection. The sensitivity of the nanophosphor HSV-2 LFA was higher than that of commercially-available rapid HSV-2 assays tested with the same panel. Analysis of the iPhone nanophosphor HSV-2 LFA strip images with our custom smartphone app gave greater reproducibility compared to ImageJ analysis of strip images. The smartphone-based nanophosphor LFA technology shows promise for private self-testing for sexually-transmitted infections (STI).单纯疱疹病毒2型（Herpes Simplex Virus Type 2, HSV-2）是一种可引发终生感染的常见人类病原体。美国15至49岁人群中，HSV-2感染的患病率为11.9%。感染HSV-2的个体更易感染并传播其他性传播感染（Sexually Transmitted Infections, STI）。80%的HSV-2感染者并未察觉自身已被感染，部分原因在于性传播感染门诊检测所伴随的社会污名化。本研究针对一款以铝酸锶长效发光纳米颗粒（纳米荧光粉，nanophosphors）作为报告标记物、用于HSV-2感染检测的智能手机端血清学侧向流免疫层析试验（Lateral Flow Immunoassay, LFA）原型开展了初步评估。当该检测方法应用于21份涵盖不同抗HSV抗体滴度的人血浆/血清样本检测组时，其检测HSV-2感染的灵敏度达96.7%，特异性为100%。相较于使用同一检测组测试的市售快速HSV-2检测试剂盒，该纳米荧光粉基HSV-2 LFA的灵敏度更优。利用定制化智能手机应用程序对iPhone拍摄的纳米荧光粉HSV-2 LFA检测条图像进行分析，其重现性优于采用ImageJ软件对检测条图像的分析结果。综上，基于智能手机的纳米荧光粉LFA技术在性传播感染私密自检领域展现出良好的应用前景。