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.