Background: Herpes simplex virus type 1 (HSV-1) is prevalent worldwide and causes mucocutaneous infections of the oral area. We aimed to define the frequency and anatomic distribution of HSV-1 reactivation in the facial area in persons with a history of oral herpes.
Methods: Eight immunocompetent HSV-1 seropositive adults were evaluated for shedding of HSV-1 from 12 separate orofacial sites (8 from oral mucosa, 2 from nose, and 2 from conjunctiva) 5 days a week and from the oral cavity 7 days a week for approximately 5 consecutive weeks by a HSV DNA PCR assay. Symptoms and lesions were recorded by participants.
Results: Herpes simplex virus type 1 was detected at least from 1 site on 77 (26.5%) of 291 days. The most frequent site of shedding was the oral mucosa, with widespread shedding throughout the oral cavity. Lesional shedding rate was 36.4% (4 of 11 days with lesions), and the asymptomatic rate was 27.1% (65 of 240 nonlesional days). In individual participants, the median rate of HSV shedding by HSV PCR was 19.7% of days (range, 11%-63%).
Conclusions: Reactivation of HSV-1 on the oral mucosa is common and usually asymptomatic. However, HSV-1 is rarely found in tears and nasal mucosa. Frequent oral shedding of HSV-1 may increase the risk for transmitting the virus to both oral and genital mucosa of sexual partners.