Genital Herpes Simplex Frequency of Recurrence

"Frequency of recurrence

Approximately 80% to 90% of persons with a symptomatic first episode of HSV-2 genital infection will have a recurrent episode within the following year, compared with 50% to 60% of patients with HSV-1 infection.

Reactivation decreases in frequency over time in most patients. Ninety-five percent of patients with primary HSV-2 have recurrences, with a median time to the first recurrence of approximately 50 days. Fifty percent of patients with primary HSV-1 have recurrent outbreaks, and the median time to the first recurrence is 1 year. Median recurrence rates in the first year are one (HSV-1) and five (HSV-2) per year in patients with newly acquired infection. Patients infected with HSV-2 who were followed for more than 4 years had a median decrease of two recurrences between years 1 and 5. However, 25% of these patients had an increase of at least one recurrence in year 5. Decreases over time among patients who never received suppressive therapy were similar to decreases during untreated periods in patients who received suppressive therapy. Patients who had severe primary infection had recurrences nearly twice as often and had a shorter time to first recurrence compared with those who had shorter first episodes. "