Subclinical reactivation of herpes simplex virus type 1 in the oral cavity

Abstract

Reactivation in the oral cavity either symptomatically (recrudescence) or without symptoms (recurrence) may contribute to the transmission of herpes simplex virus type 1 (HSV‐1), especially in critical areas of exposure such as dentistry. In order to measure the frequency of HSV‐1 reactivation, nested polymerase chain reaction (PCR) was performed on oral swabs collected from 30 healthy people over a period of 58–161 days. In total 19 of 25 (76%) seropositive people were PCR‐positive at least once, 6 of these 19 (32%) had recrudescence and 13 (68%) had only asymptomatic reactivation. Frequencies of additional recurrences were higher in people showing symptomatic reactivation than in those who had only recurrences. Recrudescence is a risk factor for elevated levels of asymptomatic HSV‐shedding. In most cases HSV‐1 was detected only by nested PCR investigated by early onset of therapy or time span before sampling.