Let me be quick and to the point - If you are positive for HSV2 then your picture can remain asymptomatic in terms of rashes or eveolve over years into full blown rash recurrences and "everything in between." This is a variable disease and people present differently. Asymptomatic shedding to most health professionals simply means you transfer disease without having obvious rash or physical outward signs - period. many people "shed' disease and don't know they are HSV@ positive - they are not prompted to get tested because they don't have the physical clues.
And viruses are really hard to test for - but the IgG ad IgM blood tests are considered the current best tests - if you have it - one of those 2 tests - if not both - will diagnose it.