Grace - check out this out.
http://www.fhcrc.org/en/news/center-news/2013/05/genital-herpes-suppressing-cells-identified.html
we don't blood test children for herpes . we don't have fda approved tests that are accurate in them until they are at least 14 years of age ( exception being we still do use herpes igm testing in infants under 1 year ).
once your children are old enough to have "the talk" with them, let them know that hsv1 is the cause of cold sores, 1 out of every 3 people they know has it by their teenage years and to be aware of it. they should avoid kissing others when they have active cold sores and to only give and receive protected oral sex unless it's a long term partner whose full std status they are aware of.
grace