Tests
1st tests to order
HSV polymerase chain reaction (PCR)
Test
Virologic testing (nucleic acid amplification test or viral culture) from the swab of an active lesion is the preferred method to establish diagnosis and distinguish between types 1 and 2.
Order when lesions are present. Do not use PCR testing to screen for genital HSV infection in asymptomatic patients. HSV shedding is intermittent, therefore PCR testing is unlikely to confirm the diagnosis if no lesions are present.[39][40]
Highest yield if vesicles can be unroofed and the base of an ulcer can be scraped with a Dacron swab.
Place swab into PCR buffer.
Higher sensitivity than viral culture.[37]
Other nucleic acid amplification tests methods have shown similar results and can be used for herpes simplex virus diagnosis.[38]
Result
positive (copies/mL)
viral culture
Test
Virologic testing (nucleic acid amplification test or viral culture) from the swab of an active lesion is the preferred method to establish diagnosis and distinguish between types 1 and 2.
Order when lesions are present.
Highest yield if vesicles can be unroofed and the base of an ulcer can be scraped with a Dacron swab. Place swab into a viral transport media.
Culture may be needed for phenotypic resistance testing.
Result
virus detected
Tests to consider
Glycoprotein G-based type-specific serology (gG1 and gG2)
Test
Routine screening is not recommended in asymptomatic adolescents, adults, and pregnant patients due to the high false-positive rate.[42] May be useful to confirm diagnosis in patients with atypical complaints or previously undiagnosed genital ulcer disease.[41] US guidelines recommend two-step serologic testing for HSV; commercially-available type-specific enzyme immunoassays may have poor specificity and a confirmatory test with a second-method (Western blot or Biokit) is advised.[36]
IgM testing is not recommended because it is not type-specific and cannot distinguish between primary versus recurrent episodes of HSV infection.[36][38]
Result
positive antibody to HSV-1 or HSV-2
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