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Review: Serological
tests for herpes simplex virus that can accurately distinguish
between HSV-1 and HSV-2 are now commercially available.
Serological testing
for herpes simplex virus (HSV)-1 and HSV-2 infection.
Wald A, Ashley-Morrow R.
Clin Infect Dis 2002;35 (Suppl 2):S173-82
Question
What are the performances and uses of commercially available HSV-1 and
HSV-2 type-specific serology tests?
Study Selection Criteria
Commercially available serological assays that detect and distinguish
antibodies to HSV glycoproteins G-1 and G-2, which evoke a type-specific
antibody response, were discussed.
Data Extraction
The evidence for the performance and use of five test kits based on
glycoprotein G was evaluated. 1) HerpeSelect-1 ELISA and HerpeSelect-2
ELISA (Focus Technologies, formerly MRL Diagnostics, Cypress, CA) are
enzyme-linked immunosorbent assays for detection of HSV-1 or HSV-2
antibodies, respectively, that can be semi-automated for high throughput.
2) HerpeSelect1/2 Immunoblot (Focus Technologies) is a nitrocellulose
strip immunoblot that simultaneously detects and distinguishes antibodies
to HSV-1, HSV-2, type-common, and control antigens, suited to low-volume
laboratory settings. The kits use bacculovirus recombinant gG-1 and gG-2
antigens. 3) POCkit HSV-2 (Diagnology, Belfast, UK) is a point of care
test only for HSV type 2 antibodies, which uses lectin-purified gG-2 and a
lateral flow membrane format. It is designed for direct patient testing of
blood or single sera in the laboratory. The FDA has approved but limited
the use of these three tests to diagnosis in adults. 4) Captia Select EIA
(Wampole Laboratories) and 5) Cobas Core HSV-2 IgG EIA (Roche) detect only
HSV-2 antibodies and are not yet FDA approved. These commercial kits were
evaluated against gold standard HSV antibody tests, including Western blot
(University of Washington) and a monoclonal antibody blocking assay
(Central Public Health Laboratory, London), which distinguish between
antibodies to HSV-1 and HSV-2.
Main Results
The performances of 5 commercial glycoprotein G-based tests for detection
of type-specific HSV antibodies are shown in the table. The accuracy of
commercial tests that are not based on glycoprotein G is low compared with
gG-based assays, and their use is not recommended. HSV-1 and HSV-2
antibodies can be detected a median of 2-3 weeks and 2 weeks after the
onset of first episode of genital herpes with the HerpeSelect ELISA and
the POCkit-HSV-2 kit, respectively. The reading of a positive POCkit-HSV-2
test is subjective and caution is advised in interpreting the results.
Settings in which type-specific
serologies for the diagnosis of HSV-1 and HSV-2 infection are useful
include patients with atypical or no genital symptoms who are at risk of
STD acquisition, patients who are seropositive for HSV-1 who are at risk
of acquiring HSV-2, confirmation of a clinical diagnosis, and determining
the type-specific serostatus of sexual partners and pregnant women.
Knowledge of type-specific HSV infection will help clinicians provide
education and counseling to prevent transmission to sex partners and
neonates.
| Performances of
commercial gG-based type-specific HSV antibody tests |
| Test |
Parameter
by HSV antibody typy |
| HSV-1 |
HSV-2 |
| Sensitivity
(%) |
Specificity
(%) |
Sensitivity
(%) |
Specificity
(%) |
| HerpeSelect
ELISA |
89-100 |
89-98 |
96-100 |
96-97 |
| HerpeSelect
Immunoblot |
99-100 |
93-96 |
97-100 |
94-98 |
| POCkit-HSV-2 |
NA* |
NA |
93-96 |
95-98 |
| Cobas-HSV-2 |
NA |
NA |
93 |
98 |
| Captia
Select-HSV-2 |
NA |
NA |
90-92 |
91-98 |
| *The POCkit-HSV-2,
Cobas-HSV-2, and Captia Select-HSV-2 tests only detect HSV-2
antibodies |
Conclusions
The commercial availability of type-specific
antibody tests for HSV-1 and HSV-2 will increase the diagnosis of this
infection. Only glycoprotein G-based tests have acceptable accuracy.
Populations appropriate for serological testing for HSV include pregnant
women, STD clinic patients, and persons with HIV infection.
For correspondence: Anna
Wald, University of Washington Virology Research Clinic, 1001 Broadway,
Ste. 320, Seattle, WA. E-mail address: annawald@u.washington.edu.
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