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).