This test screens for herpes, an STD that can cause painful sores around the mouth or genitals. The test checks for both types of herpes: herpes type-1 most often causes oral herpes and herpes type-2 most often causes genital herpes, although herpes type-1 is responsible for an increasing proportion of genital infections. Although there is no cure for herpes, treatment can help relieve the symptoms and prevent future episodes.