Detection of herpes simplex virus DNA in serum and oral secretions during acute recurrent herpes labialis

Although herpes simplex virus (HSV) has been detected in the peripheral blood of immunocompromised patients and in neonates with disseminated disease, the extent to which the virus may be present in the blood during a localized infection in otherwise healthy patients is still unknown. Literature on patterns of HSV shedding into the oral cavity at the prodromal stage of the disease, during recurrences, and also during asymptomatic periods is still lacking. The present study aims at the detection of HSV DNA in the serum and oral secretions during acute herpes labialis using a highly sensitive technique, the polymerase chain reaction (PCR). The study included 10 patients with acute herpes labialis and five healthy controls. Using PCR, herpes simplex virus DNA was detected in the serum of seven patients (70%) and in the saliva of nine patients (90%). One of the control cases showed positive HSV DNA in the saliva (20%). There was good statistical agreement between the presence of HSV DNA in the serum and saliva. Frequency of attacks, patient's age, and gender had no statistically significant effect oil the presence of the virus in serum or in saliva. It is concluded that HSV viremia during attacks of recurrent herpes simplex is more frequent than previously appreciated.