Herpes Simplex Virus-1 and -2 Rapid Detection in Whole Blood

Background Disseminated herpes simplex virus (HSV) infection has high morbidity and mortality, particularly in neonates, and requires rapid diagnosis for proper treatment. Currently, there are no US FDA-approved assays available to perform HSV testing on blood. Objectives Our goal was to evaluate the analytical sensitivity and clinical performance of an available sample-to-answer real-time polymerase chain reaction (PCR) platform used as a laboratory-developed test (LDT) for the detection of HSV-1 and -2 in whole blood (WB). Methods A clinical comparison study comparing a real-time PCR reference assay to a LDT based on the DiaSorin Simplexa Direct assay kit was performed. Analytical sensitivity studies comparing WB to the FDA-approved specimen type, cerebrospinal fluid (CSF), were also conducted with contrived quantified HSV-1 and -2 samples in WB and CSF matrix. Results In total, 102 samples were tested using the LDT and reference assay for the clinical correlation study, with 91 negative and 10 positive results for HSV-1 ( n = 7) and HSV-2 ( n = 3), exhibiting 100% concordance with comparator results. The overall limit of detection (LoD) for HSV-1 and HSV-2 in WB was comparable to that seen in CSF, with the calculated 95% LoD for blood being 1489 ± 16 copies/ml for HSV-1 and 1187 ± 18 copies/ml for HSV-2 and for CSF being 1168 ± 17 copies/ml for HSV-1 and 953 ± 21 copies/ml for HSV-2. Conclusions The performance of the LDT for detection of HSV-1 and HSV-2 in WB specimens is adequate for clinical use. The LoD for HSV-1 and HSV-2 is comparable to that in CSF, the FDA-approved specimen type.