Longitudinal evaluation of herpes simplex virus DNA load during episodes of herpes labialis.

BACKGROUND: Few studies have performed sequential evaluation of the herpes simplex virus (HSV) load using quantitative PCR during episodes of herpes labialis. OBJECTIVE: To determine HSV viral load kinetics during recurrences of herpes labialis. STUDY DESIGN: Twenty-two subjects were monitored by daily swabs during recurrences of herpes labialis. A real-time PCR detecting both HSV-1 and HSV-2 was used to quantify the viral load. RESULTS: Median duration of HSV-1 shedding was 60 h and 48 h by PCR and culture, respectively. No HSV-2 DNA was detected in that study. Peak viral DNA load (123.6 copies/cell) occurred at 48 h with no virus detected beyond 96 h of onset of symptoms. CONCLUSIONS: These viral load kinetics data could be used as surrogate markers of antiviral activity in future clinical trials.