To answer whether a patient has HSV disease, false positive diagnoses can be avoided if tests are performed in high-probability of disease situations and NOT as simple screening tests! And, proper samples must be obtained. If the sample be a blood specimen, the disease state must have had sufficient time to mount an antibody response (in an immunocompetent patient). If the sample be of tissue, it must contain viropathic cells containing a sufficient viral load to be visible in DFA tests or amplifiable in molecular tests (such as PCR). Via this link, place HSV in the top left search box to see the many test modes for HSV (HERE).
Patients & physicians often present with ACUTE lesions &, directly or indirectly, want to know if it is herpetic. Local gynecologic speakers tell
us that acute, apparently "first" lesions, can be managed as if herpetic until several weeks later when serologic testing can then be performed at a time when the
antibody level has become detectible. Or they want to know if a CHRONIC HSV
status is type I or II. Type I tends to infrequently recurr; type II tends to frequently recurr.
In our lab, this " Herpes Select 2" is
a type-specific western-blot-like "strip immunoblot" patient's-serum-test only for
IgG antibodies (at a certain height or higher3). It differentiates between
HSV I & II by antibody detection of either the IgG HSV I type
specific glycoprotein gG-1 or the IgG HSV II type specific glycoprotein
gG-2. The reagent antigens are by recombinant preparations (Focus
Technology's HerpesSelect Immunoblot [IB] strip tests). Color producing
reactions are by ELISA. The one for HSV II has, by comparison to
UW-WB testing, a sensitivity of 97-100% and a specificity of 94-98%
in clinical trials. We started reporting this test from LML on
29 October 2004. [HSV testing]
"Select" Negative, Non reactive, undetectible status:
- persons (1) with a lesion NOT due to herpes & (2) who have never had HSV II.
- HSV II infected persons whose Ab level has not yet reached
- previously infected persons who (1) did not mount a detectible
level of Ab (may or may not be "immune") or (2) whose antibody level has receeded to nondetectible levels.
- previously infected persons who have become seriously immunocompromised
and cannot produce detectible levels of IgG Ab.
Elevated, reactive, or positive results:
- represents true evidence of HSV II present or past infection.
- false positive of undetermined etiology: the
lower the disease prevalence in the population of the tested
patient (high prevalence in STD clinic...expected low prevalence
in children), the lower the positive predictive value (example: a positive
test of 98% specificity when the expected disease prevalence
is only 3% has a positive predictive value of just 0.61).
- Ashley RL, "Performance and Use of HSV...", Herpes
9 (2):38-45, 2002. (JBC & LML)
- Focus Diagnostic's website about
- Carter JB, memo, "Various LML QA Projects, Summer 2012", 17 January 2013.
(posted 30 October 2004; lates
adjustment, 21 January 2013)