Thank you for your query at DoctorSpring.com
I understand your concern.
Yes even without outbreaks, if there has been an exposure, then herpes antibodies HSV IGM/IGG will be positive in the individual. HSV IGM indicates a more recent infection, while HSV-IGG will be indicative of an infection in the past. A lot of people are completely asymptomatic, however on routine testing it is picked through the antibody testing showing that outbreaks are not necessary for the antibodies to be positive in the serum.
Hope this was helpful,