A team of US researchers looked at patterns of genital virus shedding in 498 people who had tested positive for herpes simplex virus type-2.
They found that, although asymptomatic individuals shed virus in the genital tract less frequently, they shed about as many virus particles subclinically as those with symptoms.
Among individuals with asymptomatic infections, genital herpes virus shedding occurred on 10% of days during the study period.
The researchers also found that men can have subclinical shedding.
They said their findings suggested that those who learn through serological testing that they are infected with herpes should be given tailored advice.
This should include information on recognising genital symptoms, the potential for transmission and guidance on reducing the risk of passing the infection on to partners.