Evaluation of an enzyme immunoassay system for measuring herpes simplex virus (HSV) type 1-specific and HSV type 2-specific IgG antibodies

Characterization of Serum Samples With Discordant Results in 2 Herpes Simplex Virus Type 2 IgG Assays

BACKGROUND

Our laboratory system tests sera for herpes simplex virus type 2 (HSV-2) IgG using the DiaSorin Liaison chemiluminescent immunoassay (CIA), with the option to confirm positive samples by a laboratory-developed HerpeSelect inhibition assay. As part of the confirmation process, the HerpeSelect HSV-2 IgG enzyme immunoassay (EIA) is performed. This study investigated the relationship between DiaSorin HSV-2 IgG CIA-positive indices and HerpeSelect HSV-2 IgG EIA results.

METHODS

HerpeSelect HSV-2 IgG EIA results were compiled for a cohort of consecutive DiaSorin HSV-2 IgG CIA-positive (index ≥1.10) samples. To further characterize DiaSorin CIA-positive samples that were positive (concordant) or negative (discordant) by the HerpeSelect EIA, a separate composite reference study panel was constructed and also tested using the Biokit HSV-2 IgG assay and an HSV-2 IgG inhibition assay developed for the DiaSorin instrument. Samples were classified as DiaSorin HSV-2 IgG true positive or false positive based on a composite reference using HerpeSelect EIA, Biokit, and DiaSorin inhibition results.

RESULTS

Of 2305 consecutive DiaSorin HSV-2 IgG CIA-positive samples, 411 (17.8%) were HerpeSelect HSV-2 IgG EIA negative; 343 of 411 (83%) had DiaSorin indices of 1.10 to 3.00. For the composite reference study panel (N = 120), 59 of 60 discordant samples were classified as DiaSorin HSV-2 IgG false positive based on the composite reference, whereas 58 of 60 concordant samples were classified as true positive.

CONCLUSIONS

Nearly all DiaSorin HSV-2 IgG CIA-positive but HerpeSelect HSV-2 IgG EIA-negative sera are falsely positive in the DiaSorin CIA. Furthermore, most DiaSorin false-positive samples exhibit low-positive indices, suggesting that guidelines for confirmatory testing should include low-positive samples by CIA and EIA.

Herpes Simplex Virus Type 2 Seroprevalence and Incidence and Growth of Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women

Reproductive tract infections have long been hypothesized to be risk factors for development of uterine fibroids, but few studies have investigated the issue. In our 2016 cross-sectional analysis from the Study of Environment, Lifestyle and Fibroids (2010-2018), a large Detroit, Michigan, community-based cohort study of 23- to 35-year-old African-American women with ultrasound fibroid screening, we found no association between a very prevalent reproductive tract infection, herpes simplex virus type 2 (HSV-2), and fibroids. With prospective data from the cohort (ultrasounds performed every 20 months over 5 years), we examined HSV-2's associations with fibroid incidence (among 1,208 women who were fibroid-free at baseline) and growth (among women with fibroids at baseline or diagnosed during the study). Using Cox proportional hazards models, we computed adjusted hazard ratios and 95% confidence intervals for fibroid incidence comparing HSV-2-seropositive women with HSV-2-seronegative women. The influence of HSV-2 infection on growth was assessed on the basis of the difference in fibroid size between successive ultrasounds (1,323 growth measures) using a linear mixed model, estimating the percent difference in growth scaled to 18 months. HSV-2 seropositivity was not associated with fibroid incidence (adjusted hazard ratio = 0.88, 95% confidence interval: 0.69, 1.12) or growth (estimated growth difference = 3.1%, 95% confidence interval: -5.8, 13.0). Women can be reassured that HSV-2 infection is unlikely to increase their risk of fibroid-related health problems, given these longitudinal measures.

Validation of a membrane touch biosensor for the qualitative detection of IgG class antibodies to herpes simplex virus type 2

A 1920s dead-stop end-point titration technique revisited for blood antibody analysis.

Herpes Simplex Virus Type 2 Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women

For decades reproductive tract infections (RTIs) have been hypothesized to play a role in uterine fibroid development. The few previous studies conducted used self-reported history of RTIs and had inconsistent findings. We investigated this hypothesis further using serological analysis, an immunological measure of past exposure. We focused on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association with fibroids, and serology for HSV-2 is much more sensitive than self-report. We used cross-sectional enrollment data from African-American women enrolled in a prospective study of fibroid incidence and growth (recruited 2010-2012) in the Detroit, Michigan, area. The women were aged 23-34 years and were screened for fibroids using a standardized ultrasound examination at their enrollment. Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. Of 1,696 participants, 1,658 had blood samples and HSV-2 serology results; 22% of participants with serology results had fibroids. There was no significant association between HSV-2 seropositivity and the presence of fibroids (multivariable-adjusted odds ratio = 0.94, 95% confidence interval: 0.73, 1.20), nor were there any associations with size of the largest fibroid, number of fibroids, or total fibroid volume. Our data provide no evidence for an influence of HSV-2 exposure on fibroid risk in young African-American women. Further study of other serologically measured RTIs is warranted.

Evaluating the performance of the focus HerpeSelect® HSV-2 IgG in veterans with chronic hepatitis C infection

Epidemiologic links between chronic hepatitis C and herpes simplex type-2 infection have been suggested; however, type-specific tests for HSV-2 infection have not been validated in patients with chronic hepatitis C infection. The Focus HerpeSelect(®) HSV-2 IgG (Cypress, California) assay and the Biokit HSV-2 rapid assay (Biokit USA, Lexington, MA) were performed on serum samples obtained from 84 veterans with chronic hepatitis C who demonstrated a previously positive HSV-2 serologic test in their medical records. Using the Biokit HSV-2 as the comparator assay, the positive predictive value, and specificity for the HerpeSelect(®) HSV-2 assay were 62.1% (95%CI: 49.3-73.8) and 41.9% (95%CI: 27.0-57.9), respectively. Increasing the HerpeSelect(®) HSV-2 index value defining a positive test result from >1.1 to ≥2.89 increased the assay's specificity to 97.7% (95%CI: 87.7-99.6) and the positive predictive value to 94.1%(95%CI: 71.2-99.0). J. Med. Virol. 9999: 1-5, 2015. © 2015 Wiley Periodicals, Inc. In veterans with chronic hepatitis C infection, HerpeSelect(®) HSV-2 index values between 1.1 and 2.89 should be confirmed with an alternate test for HSV-2 infection.

The diagnosis of genital herpes - beyond culture: An evidence-based guide for the utilization of polymerase chain reaction and herpes simplex virus type-specific serology

Accurate identification of persons with genital herpes is necessary for optimal patient management and prevention of transmission. Because of inherent inaccuracies, clinical diagnosis of genital herpes should be confirmed by laboratory testing for the causative agents herpes simplex virus type 1 (HSV-1) and HSV type 2 (HSV-2). Further identification of the HSV type is valuable for counselling on the natural history of infection and risk of transmission. Laboratory methods include antigen detection, culture, polymerase chain reaction (PCR) and conventional and type-specific serology (TSS). PCR has, by far, the greater sensitivity and should be the test of choice for symptomatic cases. HSV-2 TSS is indicated for patients with genital lesions in whom antigen detection, culture or PCR fail to detect HSV, and for patients who are asymptomatic but have a history suggestive of genital herpes. HSV-2 TSS is further indicated for patients infected with HIV. HSV-2 TSS along with HSV-1 TSS may be considered, as appropriate, in evaluating infection and/or immune status in couples discordant for genital herpes, women who develop their first clinical episode of genital herpes during pregnancy, asymptomatic pregnant women whose partners have a history of genital herpes or HIV infection, and women contemplating pregnancy or considering sexual partnership with those with a history of genital herpes. The above should be performed in conjunction with counselling of infected persons and their sex partners.

Evaluation of three multiplex flow immunoassays compared to an enzyme immunoassay for the detection and differentiation of IgG class antibodies to herpes simplex virus types 1 and 2

The diagnosis of herpes simplex virus (HSV) infections is routinely made based on clinical findings and supported by laboratory testing using PCR or viral culture. However, in instances of subclinical or unrecognized HSV infection, serologic testing for IgG class antibodies to type-specific HSV glycoprotein G (gG) may be useful. This study evaluated and compared the performances of three multiplex flow immunoassays (AtheNA Multi-Lyte [Zeus Scientific], BioPlex 2200 [Bio-Rad Laboratories], and Plexus HerpeSelect [Focus Diagnostics]) for the simultaneous detection of gG type-specific IgG antibodies to HSV types 1 and 2 (HSV-1 and HSV-2). Serum specimens (n = 505) submitted for routine gG type-specific HSV IgG testing by enzyme immunoassay (EIA) (HerpeSelect; Focus Diagnostics) were also tested by the three multiplex flow immunoassays. Specimens showing discordant results were tested by HSV type-specific Western blotting (WB). For HSV-1 IgG, the AtheNA, BioPlex, and Plexus assays demonstrated agreements of 94.9% (479/505 specimens), 97.8% (494/505 specimens), and 97.4% (492/505 specimens), respectively, with the results of EIA. For HSV-2 IgG, the AtheNA, BioPlex, and Plexus assays showed agreements of 87.9% (444/505 specimens), 97.2% (491/505 specimens), and 96.8% (489/505 specimens), respectively, with EIA results. Timing studies showed that the AtheNA, BioPlex, and Plexus assays could provide complete analysis of 90 serum specimens in 3.1, 1.5, and 2.9 h, respectively, versus 3.1 h by EIA. These findings suggest that the gG type-specific HSV IgG multiplex immunoassays may be beneficial to high-volume clinical laboratories experiencing significant increases in the number of specimens submitted for HSV serologic testing. The evaluated systems provide comparable results to those of EIA, while reducing hands-on time and eliminating the necessity to aliquot specimens prior to testing.

Herpes simplex virus type 2 and HIV infection among US military personnel: implications for health prevention programmes

US military personnel are routinely screened for HIV infection. Herpes simplex virus type 2 (HSV-2) is a risk factor for HIV acquisition. To determine the association between HSV-2 and HIV, a matched case-control study was conducted among US Army and Air Force servicemembers with incident HIV infections (cases) randomly matched with two HIV-uninfected servicemembers (controls) between 2000 and 2004. HSV-2 prevalence was significantly higher among cases (30.3%, 138/456) than among controls (9.7%, 88/912, P < 0.001). HSV-2 was strongly associated with HIV in univariate (odds ratio [OR] = 4.2, 95% confidence interval [CI] = 3.1–5.8) and multiple analyses (adjusted [OR] = 3.9, 95% CI = 2.8–5.6). The population attributable risk percentage of HIV infection due to HSV-2 was 23%. Identifying HSV-2 infections may afford the opportunity to provide targeted behavioural interventions that could decrease the incidence of HIV infections in the US military population; further studies are needed.

Serologic detection of herpes simplex virus type 2 antibodies among pregnant women using a point-of-care test from Focus Diagnostics

BACKGROUND

Serologic assays that identify herpes simplex type 2 (HSV-2) type-specific antibodies have been commercially available for more than a decade. Greater acceptance of these tests is hindered by uncertainty regarding their performance in real-world clinical settings.

OBJECTIVES

The primary objective was to compare the test characteristics of the Focus HerpeSelect Express Assay (EA) versus the Focus HerpeSelect enzyme linked immunoassay (ELISA) for detection of HSV-2 type-specific antibodies among pregnant women enrolled from 3 geographic sites with varying prevalences of HSV-2 infection. A second objective was to evaluate the performance of a HSV-2 testing strategy in which EA screens and ELISA confirms HSV-2 serodiagnosis.

STUDY DESIGN

We enrolled 399 pregnant women from Atlanta, GA, Moorestown, NJ, and Pittsburgh, PA into this cross-sectional investigation. Capillary whole blood was obtained from study participants, and evaluated for the presence of type-specific HSV-2 antibodies using the EA. Serum samples were also obtained from all study participants for subsequent identification of HSV-2 type-specific antibodies using both ELISA and the Focus Immunoblot assays.

RESULTS

We observed 96.2% agreement between results obtained with EA and ELISA. Overall, when compared to ELISA results, the sensitivity of EA for detection of HSV-2 type-specific antibodies was 94.2% and the specificity was 97.1%. Using Immunoblot results as our standard for performance calculations, the positive predictive value (PPV) of HSV-2 serodiagnosis increased from 91.7% to 98.2% when ELISA was used to confirm EA testing.

CONCLUSIONS

EA provides similar results to ELISA for the identification of HSV-2 type-specific antibodies among pregnant women. As use of the point-of-care (POC) EA in conjunction with confirmatory ELISA testing improves the PPV of HSV-2 serodiagnosis compared to the use of EA or ELISA testing alone, validation of this diagnostic algorithm in other at-risk populations may be warranted.

Improved performance of enzyme-linked immunosorbent assays and the effect of human immunodeficiency virus coinfection on the serologic detection of herpes simplex virus type 2 in Rakai, Uganda

Ugandan subjects (820) were tested by Focus HerpeSelect enzyme-linked immunosorbent assay (ELISA), Kalon herpes simplex virus type 2 ELISA, and BioKit rapid test, and the results were compared to those of Western blotting. Higher-than-standard-index cutoff values gave optimal sensitivity and specificity. Kalon ELISA was the optimal assay when an index value of 1.5 was used (sensitivity, 91.7%; specificity, 92.4%).

Seroprevalences of herpes simplex virus type 2, five oncogenic human papillomaviruses, and Chlamydia trachomatis in Katowice, Poland

Herpes simplex virus type 2 (HSV-2), human papillomaviruses (HPVs), and Chlamydia trachomatis are the most common pathogens causing sexually transmitted infections (STIs). There is limited information about the prevalences of these STIs in Poland. Here, we estimated the occurrence of immunoglobulin G (IgG) antibodies against HSV-2, HPV, and C. trachomatis in 199 blood donors and 110 patients of both genders attending an STI clinic in Katowice in southern Poland. The seroprevalences of HSV-2 were 5% for blood donors and 14% in the STI cohort. The seroprevalences of the five potentially oncogenic HPV types 16, 18, 31, 35, and 51 were 15%, 7%, 5%, 5%, and 17%, respectively, in blood donors and 37%, 8%, 12%, 5%, and 21%, respectively, in the STI cohort. The majority of HPV-infected individuals showed antibodies against more than one type, i.e., had been infected with multiple HPV types. Anti-C. trachomatis IgG antibodies were detected in 6% of blood donors and 13% of individuals attending the STI clinic. The relatively high prevalence of HPV-51 may have implications for future vaccine programs, as the newly introduced HPV vaccines are based on the potentially oncogenic HPV types 16 and 18.

Rapid, sensitive, and specific lateral-flow immunochromatographic point-of-care device for detection of herpes simplex virus type 2-specific immunoglobulin G antibodies in serum and whole blood

Herpes simplex virus type 2 (HSV-2) is a common human pathogen that can cause a variety of clinical manifestations in humans. In order to provide near-patient results to allow for faster counseling and treatment, a rapid point-of-care test that is accurate and simple to use is desirable. Here, we describe the development and evaluation of an HSV-2 immunoglobulin G (IgG)-specific antibody lateral-flow immunochromatographic assay (LFIA) based on colloidal gold nanoparticles. A total of 359 serum samples and 100 whole-blood samples were tested in the newly developed HSV-2 LFIA. Serum results were compared to those from the HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA), and whole-blood sample results were compared to those of both ELISA and HerpeSelect HSV-1 and -2 immunoblotting (IB). The sensitivity of the HSV-2 LFIA compared to that of the HerpeSelect ELISA was 100% (89/89), and the specificity was 97.3% (257/264). Cross-reactivity with HSV-1 IgG-positive serum samples was observed in 2.6% (5/196) of samples, 2.9% (1/34) for rubella virus, and 6.2% (1/16) for Epstein-Barr virus. No cross-reactivity in varicella-zoster virus or cytomegalovirus IgG-positive serum samples was observed. No interference was observed from bilirubin-, triglyceride-, albumin-, or hemoglobin-spiked samples. The concordance of the LFIA results between capillary whole blood, EDTA-treated venous whole blood, heparin-treated venous whole blood, and serum was 99% (99/100). In conclusion, the LFIA for HSV-2 IgG-specific antibodies demonstrated excellent sensitivity, specificity, and concordance for both serum and whole-blood samples compared to the sensitivity, specificity, and concordance of both HSV-2 ELISA and IB.

Herpes simplex virus (HSV) suppression with valacyclovir reduces rectal and blood plasma HIV-1 levels in HIV-1/HSV-2-seropositive men: a randomized, double-blind, placebo-controlled crossover trial

BACKGROUND

Herpes simplex virus type 2 (HSV-2) infection is common among human immunodeficiency virus (HIV)-infected persons, and HSV reactivation increases plasma and genital HIV-1 levels. We studied HIV-1 levels during HSV suppression in coinfected persons in a placebo-controlled crossover trial.

METHODS

Twenty antiretroviral therapy (ART)-naive HIV-1/HSV-2-seropositive men who have sex with men in Lima, Peru, with CD4 cell counts >200 cells/ microL were randomized to receive either valacyclovir at 500 mg twice daily or placebo for 8 weeks, after which they underwent a 2-week washout period and then received the alternative regimen for 8 weeks. Specimens included daily anogenital swabs (for HSV DNA polymerase chain reaction [PCR]), thrice weekly rectal mucosal secretions (for HIV-1 RNA and HSV DNA PCR) obtained by anoscopy, and weekly plasma (for HIV-1 RNA PCR). Outcomes were rectal and plasma HIV-1 RNA levels by treatment arm.

RESULTS

HIV-1 was detected in 73% of 844 rectal and 99% of 288 plasma specimens. HSV was detected in 29% and 4% of mucocutaneous specimens obtained during placebo and valacyclovir administration, respectively (P<.001). Valacyclovir resulted in a 0.16 (95% confidence interval [CI], 0.07-0.25; P=.0008; 33% decrease) log(10) copies/mL lower mean within-subject rectal HIV-1 level and a 0.33 (95% CI, 0.23-0.42; P<.0001; 53% decrease) log(10) copies/mL lower plasma HIV-1 level, compared with values for placebo.

CONCLUSIONS

Valacyclovir significantly reduces rectal and plasma HIV-1 levels in HIV-1/HSV-2-coinfected men. HSV suppression may provide clinical benefits to persons not receiving highly active ART as well as public health benefits.

Effect of sexually transmitted disease (STD) coinfections on performance of three commercially available immunosorbent assays used for detection of herpes simplex virus type 2-specific antibody in men attending Baltimore, Maryland, STD clinics

Two hundred seventy-nine serum samples from men attending sexually transmitted disease (STD) clinics in Baltimore, Maryland, were tested for herpes simplex virus type 2 (HSV-2)-specific antibody by three immunosorbent glycoprotein G-2-based assays (the Kalon, Focus, and Biokit assays). The results for all samples with positive results were confirmed by Western blotting (91/279; 32.6% HSV-2 seroprevalence). All patients were also tested for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, human immunodeficiency virus type 1, and hepatitis C virus. The Kalon assay performed very well with samples from this population (90.8% sensitive, 99.4% specific), whereas the Focus assay had a sensitivity (82.6%) much lower than that shown previously. For 19.7% of the samples, the Biokit assay gave an indeterminate result. It was found that the odds of a sample having a Biokit assay indeterminate result compared to that of having a definitive positive or negative results were 3.88 times greater for subjects concurrently infected with N. gonorrhoeae, after the effects of other STDs were controlled for (P = 0.001; 95% confidence interval, 1.78, 8.45). Unfortunately, we were unable to control for HSV-1 infection status in the regression model, which, on the basis of chi(2) analysis, might also affect the clarity of the Biokit test. The recommended index cutoff value of 1.1 for the Focus and Kalon assays was found to be optimal for this population.

Performance of focus ELISA tests for HSV-1 and HSV-2 antibodies among university students with no history of genital herpes

OBJECTIVES

To define the performance characteristics of the Focus ELISA HSV-1 and HSV-2 assay among 100 university students.

STUDY DESIGN

HSV-1 and HSV-2 Focus ELISA and Western Blot assays were performed on sera from university students who reported no history of genital herpes.

RESULTS

HSV-2 and HSV-1 seroprevalence by Western Blot were 3.4% and 48%, respectively. In this population, the positive predictive value of the Focus HSV-2 ELISA was 37.5%, the sensitivity was 100%, and specificity was 94.1%. The PPV of the Focus HSV-1 ELISA was 96.7%, the sensitivity was 69.0%, and the specificity was 97.8%.

CONCLUSIONS

In this low-prevalence population, the positive predictive value of the Focus HSV-2 ELISA test was low. This finding, together with those reported elsewhere, indicates that caution is warranted when recommending HSV screening in low-prevalence or heterogeneous populations. Consideration should be given to raising the cutoff index value for defining a positive test result.

Herpes Simplex Virus Type 2 (HSV-2) Western Blot Confirmatory Testing Among Men Testing Positive for HSV-2 Using the Focus Enzyme-Linked Immunosorbent Assay in a Sexually Transmitted Disease Clinic

OBJECTIVE

The objective of this study was to define the positive predictive value (PPV) of the Focus herpes simplex virus type 2 (HSV-2) enzyme-linked immunosorbent assay (ELISA) in a low HSV-2 prevalence population and to develop a new test interpretation algorithm.

METHODS

HSV-2 Western blots were performed on sera from male sexually transmitted disease clinic patients testing HSV-2 ELISA-positive and used to define a new class of indeterminate HSV-2 ELISA result. HSV-2 Western blots were then prospectively performed on sequential sera with indeterminate HSV-2 ELISAs.

RESULTS

Ninety-one (84%) of 108 HSV-2 ELISA-positive sera tested HSV-2 Western blot-positive. Western blot positivity was more common in men without herpes simplex virus type 1 (HSV-1) antibody than in those with HSV-1 antibody (93% vs 76%, P = 0.02) and in men with a history or clinical evidence of genital lesions (88% vs 80%, P = 0.30). Selectively raising the ELISA index value defining HSV-2 positivity from >1.1 to >or=3.0 either among HSV-1-positive men or among those without a history or clinical evidence of genital lesions increased the PPV to >or=93%. Prospective evaluation of an algorithm incorporating HSV-1 serostatus found that 11 of 70 persons with indeterminate HSV-2 ELISAs were Western blot-positive.

CONCLUSIONS

Clinicians should consider selectively using a higher index value to define Focus ELISA HSV-2 positivity based on either HSV-1 serostatus or clinical circumstances.

Genital Herpes Complicating Pregnancy

Approximately 22% of pregnant women are infected with herpes simplex virus (HSV)-2, and 2% of women will acquire HSV during pregnancy. Remarkably, up to 90% of these women are undiagnosed because they are asymptomatic or have subtle symptoms attributed to other vulvovaginal disorders. Diagnosis of genital herpes relies on laboratory confirmation with culture or polymerase chain reaction assay of genital lesions and type-specific glycoprotein G-based serologic testing. Neonatal herpes is the most severe complication of genital HSV infection and is caused by contact with infected genital secretions at the time of labor. Maternal acquisition of HSV in the third trimester of pregnancy carries the highest risk of neonatal transmission. Despite advances in the diagnosis and treatment of neonatal herpes, little change in the incidence or serious sequelae from this infection has occurred. As such, prevention of the initial neonatal infection is critically important. Obstetricians are in a unique position to prevent vertical HSV transmission by identifying women with genital lesions at the time of labor for cesarean delivery, prescribing antiviral suppressive therapy as appropriate, and avoiding unnecessary invasive intrapartum procedures in women with genital herpes. Enhanced prevention strategies include identification of women at risk for HSV acquisition during pregnancy by testing women and possibly their partners for HSV antibodies and providing counseling to prevent transmission to women in late pregnancy.

Herpes Simplex Virus Infections in Neonates and Early Childhood

Of the commonly considered congenital infections, those caused by cytomegalovirus (CMV), syphilis, and herpes simplex virus (HSV) are frequently (CMV, HSV) or exclusively (syphilis) acquired sexually by the mother, with subsequent transmission to the developing fetus. Of the other commonly considered congenital infections, including rubella and toxoplasma infections, the mother is exposed to the infectious agent via interpersonal or environmental contacts. Unlike each of these other pathogens, which are transmitted transplacentally to the developing fetus following maternal infection though, HSV usually is transmitted perinatally as the neonate is exposed to the virus during passage through an infected birth canal. This difference in timing of acquisition of infection has had important consequence in the therapeutic advances achieved during the last 30 years in the management of neonatal HSV infections. Because the time period between the acquisition of infection and initiation of effective antiviral therapy is shorter in neonatal herpes than in congenital toxoplasmosis or CMV infections, the outcomes of therapy have the potential to be markedly different. This article will summarize the current state of neonatal HSV disease presentation, diagnosis, and management.

A branched, synthetic oligopeptide corresponding to a region of glycoprotein G of HSV-1 reacts sensitively and specifically with HSV-1 antibodies in an ELISA

Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), which are common worldwide, are so similar that antibodies directed against one serotype may crossreact with antigens from the other one. Methods for specific detection of antibodies against HSV-1 or HSV-2 are based upon the antigenicities of glycoproteins G. However, due to the cost, the available commercial methods may not readily be used in developing countries. A different enzyme-linked immunosorbent assay (ELISA) method, based upon a synthetic oligopeptide corresponding to an immunogenic region in glycoprotein G of HSV-2, has been used recently and successfully for detection of HSV-2 antibodies. In the present study, the sequences of a newly identified immunogenic and type-specific region in glycoprotein G of HSV-1 was used to synthesize three different, branched oligopeptides. The performances of these peptides in an ELISA were investigated by testing Scandinavian and African sera which were characterized by commercial ELISA and Western blotting methods and divided into four groups either lacking HSV antibodies, containing antibodies against one or the other virus, or against both types. The peptide which corresponded in sequence to the immunodominant region was as specific and sensitive by an ELISA as were the commercial methods. The method is inexpensive and reliable.

Production of herpes B virus recombinant glycoproteins and evaluation of their diagnostic potential

B virus (cercopithecine herpesvirus 1) is the only deadly alphaherpesvirus that is zoonotically transmissible from macaques to humans. The detection of humoral immune responses is the method of choice for the rapid identification of B virus-infected animals. We evaluated the diagnostic potential of recombinant B virus glycoproteins for the detection of immunoglobulin G (IgG) antibodies in monkey and human sera. Glycoproteins B, C, and E and secreted (sgG) and membrane-associated (mgG) segments of glycoprotein G (gG) were expressed in the baculovirus expression system, while gD was expressed in CHO cells. We developed recombinant protein-based IgG enzyme-linked immunosorbent assays (ELISAs) and compared their diagnostic efficacies by using B virus antibody-negative (n = 40) and -positive (n = 75) macaque sera identified by a whole antigen-based ELISA and Western blotting. The diagnostic sensitivities of the gB-, gC-, gD-, and mgG-ELISAs were 100, 97.3, 88.0, and 80.0%, respectively. The specificities of the gB-, gC-, and gD-ELISAs and of the mgG-ELISA were 100 and 97.5%, respectively. In contrast, the sensitivities and specificities of sgG- and gE-ELISAs were low, suggesting that sgG and gE are less effective diagnostic antigens. Sera from nonmacaque monkeys cross-reacted with gB, gC, and gD, and only baboon sera reacted weakly with mgG. Human herpes simplex virus type 1 (HSV-1)- and HSV-2-positive sera pools reacted with gB and gD, whereas sera from B virus-infected individuals reacted with all four antigens. These data indicate that gB, gC, gD, and mgG have a high diagnostic potential for B virus serodiagnosis in macaques, whereas mgG may be a valuable antigen for discrimination between antibodies induced by B virus and those induced by other, closely related alphaherpesviruses, including HSV-1 and -2.

Neonatal herpes: What have we learned

Neonatal herpes simplex virus (HSV) infection usually is acquired during the birth process, as the neonate comes in contact with the virus during passage through an infected birth canal. After an incubation period which can last as long as 2 to 4 weeks, neonatal HSV disease then manifests in 1 of 3 ways: (1) disseminated disease, with visceral organ involvement (including infection of the brain in two-thirds to three-quarters of patients); (2) central nervous system disease (with no other visceral organ involvement, but with skin lesions in two-thirds of patients); or (3) disease limited to the skin, eyes, and/or mouth (ie, SEM disease). Diagnostic advances in recent years have focused primarily on applying polymerase chain reaction technology to babies suspected of having neonatal HSV disease. Treatment of neonatal HSV disease with intravenous acyclovir has improved the likelihood of survival substantially, although neurologic morbidity remains a common sequelae, especially among survivors of central nervous system disease. Despite these advances, the duration of time from onset of symptoms and initiation of antiviral therapy has remained unchanged for the past 20 years. The surest way to improve outcomes rapidly at this point is to raise awareness of neonatal HSV disease, resulting in the establishment of earlier diagnoses and more rapid institution of antiviral therapy. In the longer term, development of a bedside nucleic acid detection kit for real-time detection of HSV DNA in the maternal genital tract at the time of delivery could identify which babies are at risk of developing neonatal HSV disease.

Performance of focus ELISA tests for herpes simplex virus type 1 (HSV-1) and HSV-2 antibodies among women in ten diverse geographical locations

To determine the sensitivity and specificity of Focus HerpeSelect ELISAs, sera or plasma samples from women aged 18-55 years were collected in ten cities from eight countries and tested by HerpeSelect HSV-1 ELISA (Focus-HSV-1) and by HerpeSelect HSV-2 ELISA (Focus-HSV-2). Sera with Focus-HSV-2-positive results were retested; 94% of the 3617 samples retested were positive. A subset of sera from each site was then selected, based on the HSV-2 results, and tested by Western blot (WB). The sensitivity and specificity were determined with samples from ten sites (n = 967) for Focus-HSV-1 and from seven sites (n = 675) for Focus-HSV-2. Focus-HSV-1 and WB results were concordant (both negative or both positive) for 97% of samples, with 99% sensitivity and 77% specificity. Specimens from Songkla, Thailand had 84% concordance with WB results for HSV-1, while three other sites had 100% concordance. Concordance of Focus-HSV-2 and WB was 92%, with 97% sensitivity and 89% specificity. Ibadan, Nigeria had 78% concordance. Focus-HSV-2 sensitivity and specificity in sites other than Ibadan were 97% and 93%, respectively. Raising the positive cut-off index value for HSV-2 from 1.1 to 3.5 yielded a sensitivity of 90% and a specificity of 96%. A sensitivity of 90% and a specificity of 98% were achieved for sites other than Nigeria with the higher cut-off. In summary, the sensitivity and specificity of the Focus-HSV-1 and Focus-HSV-2 tests varied by site. Performance data generated in one area may not be applicable to other populations.

Performance of a commercial, type-specific enzyme-linked immunosorbent assay for detection of herpes simplex virus type 2-specific antibodies in Ugandans

Two hundred forty-eight human immunodeficiency virus (HIV)-positive and 496 HIV-negative subjects in Uganda were tested by HerpeSelect herpes simplex virus type 2 enzyme-linked immunosorbent assay (ELISA) and Western blotting to optimize the ELISA for use in this population. A higher index cutoff value was required for optimal sensitivity and specificity, and overall performance of the assay was not affected by HIV status.

The seroepidemiology of herpes simplex virus type 1 and 2 in Europe

OBJECTIVES

To describe the seroepidemiology of herpes simplex virus (HSV) types 1 and 2 in the general populations of eight European countries to better understand recent reported changes in disease epidemiology.

METHODS

Belgium, Bulgaria, Czech Republic, England and Wales, Finland, Germany, Netherlands, and Slovenia conducted national cross sectional serological surveys for HSV-1 and HSV-2 between 1989 and 2000. Survey sizes ranged from 3000 to 7166 sera. External quality control was ensured through reference panel testing.

RESULTS

Large intercountry and intracountry differences in HSV-1 and HSV-2 seroprevalence were observed. Age standardised HSV-1 seroprevalence ranged from 52% in Finland, to 57% in the Netherlands, 67% in Belgium, 81% in Czech Republic, and 84% in Bulgaria. Age standardised (>12 years) HSV-2 seroprevalence ranged from 24% in Bulgaria, to 14% in Germany, 13% in Finland, 11% in Belgium, 9% in Netherlands, 6% in Czech Republic, and 4% in England and Wales. In all countries, probability of seropositivity for both infections increased with age. A large proportion of teenagers and young adults remain HSV-1 susceptible particularly in northern Europe. Women were significantly more likely to be HSV-2 seropositive in six of seven (p<0.05) countries and HSV-1 seropositive in four of seven (p<0.05) countries, particularly in northern Europe. No significant evidence of a protective role of HSV-1 for HSV-2 infection was found adjusting for age and sex (p<0.05).

CONCLUSIONS

There is large variation in the seroepidemiology of HSV-1 and HSV-2 across Europe. The observation that a significant proportion of adolescents are now HSV-1 susceptible may have implications for transmission and clinical presentation of HSV-1 and HSV-2.

Gender differences in sexual biomarkers and behaviors associated with human papillomavirus-16, -18, and -33 seroprevalence

BACKGROUND

The elevated risk for incident head and neck cancer among human papillomavirus (HPV)-16-seropositive individuals has substantiated a role for HPV in the etiology of head and neck cancers. The relationship between HPV seroreactivity and prevalent oral HPV infection in men and women without cancer has yet to be investigated.

GOAL

The goal of this study was to evaluate a possible association between oral HPV infection and HPV seroreactivity after adjustment for gender, sexual behaviors, and sexually transmitted disease.

STUDY DESIGN

A cross-sectional study of factors associated with HPV-16, -18, and -33 seroreactivity was performed in a population of 586 men and women with and without HIV infection. Antibodies in sera were measured by use of a virus-like protein (VLP)-based enzyme-linked immunosorbent assay. Exfoliated cells from the tonsillar and oral mucosa were analyzed for the presence of 38 mucosal HPV types by polymerase chain reaction.

RESULTS

Women had significantly greater seroreactivity for all HPV types investigated when compared with men (odds ratio, 4.3; 95% confidence interval, 3.0-6.0). Seroprevalence was greatest in men and women aged 35 to 45 years. Tonsillar HPV infection, oral sex with men, and HIV infection were independently associated with HPV seroreactivity in men after adjustment for age and number of sexual partners. In women, HSV-2 seropositivity and a history of sexually transmitted diseases were similarly important. Oral and tonsillar HPV infection were not associated with HPV seroreactivity in women.

CONCLUSION

HPV seropositivity is associated with sexually transmitted diseases among women and possibly mucosal HPV exposures in men. Tonsillar HPV infection could impact seroprevalence, particularly in men.

Performance and use of a ribonucleotide reductase herpes simplex virus type-specific serological assay

In response to the increasingly evident need for herpes simplex virus (HSV) serotype-specific serologic assays that rely on proteins other than glycoprotein-G (gG), we developed a rapid serologic assay that is based on type-specific epitopes within the large subunit of HSV ribonucleotide reductase (R1). The assay (Au-2 enzyme-linked immunosorbent assay [ELISA]) uses an HSV type 2 (HSV-2) R1 peptide antigen. It provides a reliable method for detecting serotype-specific antibody to a protein other than gG-2. The Au-2 ELISA has high sensitivity and specificity as determined by direct comparison to Western blotting, a widely accepted "gold standard," and to ELISA with an HSV-1 R1 peptide (Au-1). The use of the Au-2 ELISA in conjunction with the gG-2-based assays will improve the sensitivity and specificity of serologic diagnosis and patient management.

Adolescent sexually transmitted diseases: Recent developments

Adolescents and young adults continue to have the highest rates of sexually transmitted diseases. New chlamydia and gonorrhea diagnostic tests are being used in innovative ways to increase the number of infections that are detected. Nevertheless, challenges such as gonorrhea resistance and partner notification and treatment continue to hinder efforts to reduce the prevalence of these two bacterial infections. Although recent surveillance data suggest a decreasing trend of herpes simplex virus 2 (HSV-2) incidence among adolescents and young adults, the incidence of sexually transmitted human papillomavirus (HPV) in adolescent and young adult females remains high. Progress has been made toward the development of vaccines that may become available in the future to prevent infection with and sequelae from HSV-2 and HPV.

Neonatal herpes simplex infection

Tremendous advances have occurred over the past 30 years in the diagnosis and management of neonatal herpes simplex virus (HSV) disease. Mortality in patients with disseminated disease has decreased from 85 to 29%, and that in patients with central nervous system (CNS) disease has decreased from 50 to 4%. Morbidity has been improved more modestly: the proportion of patients with disseminated disease who are developing normally at 1 year has increased from 50 to 83%. While the proportion of patients with neurologic morbidity following CNS disease has remained essentially unchanged over the past three decades, the total number of patients who are developing normally following HSV CNS disease has increased due to the improved survival. Although additional therapeutic advances in the future are possible, more immediate methods for further improvements in outcome for patients with this potentially devastating disease lie in an enhanced awareness of neonatal HSV infection and disease. A thorough understanding of the biology and natural history of HSV in the gravid woman and the neonate provides the basis for such an index of suspicion and is provided in this article.

Secreted portion of glycoprotein g of herpes simplex virus type 2 is a novel antigen for type-discriminating serology

The secreted portion of glycoprotein G (sgG-2) of herpes simplex virus type 2 (HSV-2) was evaluated as a novel antigen in an enzyme-linked immunosorbent assay (ELISA) format for detection of type-specific immunoglobulin G (IgG) antibodies in HSV-2-infected patients. The results were compared with those obtained by a commercially available assay, the HerpeSelect 2 ELISA (the FOCUS2 assay). Five different panels of sera were analyzed: panel A consisted of 109 serum samples from patients with a culture-proven HSV-1 infection that were Western blotting (WB) negative for HSV-2; panel B consisted of 106 serum samples from patients with a culture-proven recurrent HSV-2 infection that were WB positive for HSV-2; panel C consisted of 100 serum samples with no detectable IgG antibodies against HSV-1 and HSV-2; panel D consisted of 70 HSV-2 negative "tricky" serum samples containing antinuclear IgG antibodies or IgM antibodies against other viruses or bacteria; and panel E consisted of consecutive serum samples from 21 patients presenting with a first episode of HSV-2-induced lesions. When sera in panels A to C were analyzed, the sgG-2 ELISA and the FOCUS2 assay both showed sensitivities and specificities of >or=98%. In total, among the samples in panel D, 13 serum samples (19%) were false positive by the FOCUS2 assay and 1 serum sample (1.4%) was false positive by the sgG-2 ELISA. When the sera in panel E were analyzed, the sgG-2 ELISA detected seroconversion somewhat later than WB or the FOCUS2 assay did. We conclude that sgG-2 induces an HSV-2 type-specific antibody response and can be used for type-discriminating serology.

Seroepidemiological study of herpes simplex virus types 1 and 2 in Brazil, Estonia, India, Morocco, and Sri Lanka

BACKGROUND

The association between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV) and the development of HSV vaccines have increased interest in the study of HSV epidemiology.

OBJECTIVES

To estimate the age and sex specific seroprevalence of HSV-1 and HSV-2 infections in selected populations in Brazil, Estonia, India, Morocco, and Sri Lanka.

METHODS

Serum samples were collected from various populations including children, antenatal clinic attenders, blood donors, hospital inpatients, and HIV sentinel surveillance groups. STD clinic attenders were enrolled in Sri Lanka, male military personnel in Morocco. Sera were tested using a common algorithm by type specific HSV-1 and HSV-2 antibody assay.

RESULTS

13,986 samples were tested, 45.0% from adult females, 32.7% from adult males, and 22.3% from children. The prevalence of HSV-1 varied by site ranging from 78.5%-93.6% in adult males and from 75.5%-97.8% in adult females. In all countries HSV-1 seroprevalence increased significantly with age (p<0.001) in both men and women. The prevalence of HSV-2 infection varied between sites. Brazil had the highest age specific rates of infection for both men and women, followed by Sri Lanka for men and Estonia for women, the lowest rates being found in Estonia for men and India for women. In all countries, HSV-2 seroprevalence increased significantly with age (p<0.01) and adult females had higher rates of infection than adult males by age of infection.

CONCLUSIONS

HSV-1 and HSV-2 seroprevalence was consistently higher in women than men, particularly for HSV-2. Population based data on HSV-1 and HSV-2 will be useful for designing potential HSV-2 vaccination strategies and for focusing prevention efforts for HSV-1 and HSV-2 infection.

Longitudinal reliability of focus glycoprotein G-based type-specific enzyme immunoassays for detection of herpes simplex virus types 1 and 2 in women

Serologic assays that utilize herpes simplex virus (HSV) type-specific glycoproteins G-1 (HSV-1) and G-2 (HSV-2) to discriminate between antibodies against HSV-1 and HSV-2 are sensitive and specific. However, the high rates of seroreversion, defined as the change in an individual's antibody status from positive to negative over time, previously reported in longitudinal evaluations of glycoprotein G type-specific tests suggests that their use in HSV acquisitional studies would be problematic. To further explore the reliability of the glycoprotein G-based serologic tests, we evaluated HSV-1 and HSV-2 enzyme immunoassays from Focus Technologies in a longitudinal cohort of 1207 young women from Pittsburgh, Pa. On enrollment of the women in the study, HSV-1 and HSV-2 antibodies were detected in 46.6 and 24.9% of the women, respectively. Among the women with at least three visits, 3.4% (15 of 447) of those who were HSV-1 antibody positive had a subsequent negative result while fewer than 1% (2 of 227) of those who were HSV-2 antibody positive seroreverted. The median of mean positive index values for women who seroreverted to HSV-1 antibody was lower than that for women who remained seropositive (1.25 versus 7.06; P < 0.001). Similarly, the median of mean positive index values for women whose HSV-2 antibody status reverted from positive to negative was lower than that for those women who did not serorevert (1.83 versus 7.46; P = 0.02). Comparative Western blot analysis demonstrated that the lower positive index values, seen more often among the HSV seroreverters, often signified false-positive immunoassay results. Overall, the seroreversion rates were low; the use of glycoprotein G-based serologic tests for the measurement of HSV-1 and HSV-2 antibodies in incidence studies therefore appears warranted.

Serological testing for herpes simplex virus (HSV)-1 and HSV-2 infection

Serological tests for herpes simplex virus (HSV) that can accurately distinguish between HSV-1 and HSV-2 are now commercially available. These tests detect antibodies to HSV glycoproteins G-1 and G-2, which evoke a type-specific antibody response. Focus Technologies produces the HerpeSelect-1 and HerpeSelect-2 enzyme-linked immunosorbent assay tests and the HSV-1 and HSV-2 HerpeSelect1/2 Immunoblot. Diagnology has marketed POCkit-HSV-2, a point-of-care test for HSV-2 that allows blood from a finger stick to be tested in a clinic. These tests can be used to confirm a genital herpes diagnosis, establish diagnosis of HSV infection in patients with atypical complaints, identify asymptomatic carriers, and identify persons at risk for acquiring HSV. Potential settings for use of these tests include sexually transmitted disease clinics, prenatal clinics, and clinics that care for patients with human immunodeficiency virus. Patient interest in HSV serological tests appears high.

Detection of herpes simplex virus type 2-specific immunoglobulin G antibodies in African sera by using recombinant gG2, Western blotting, and gG2 inhibition

Sera (n = 781) from four African countries were used to determine the prevalence of herpes simplex virus type 2 (HSV-2) antibodies by using the HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA; Focus Technologies) and Western blotting (WB). Also, an HSV inhibition assay was developed to evaluate the discordant sample results between HerpesSelect and WB. The seroprevalence of HSV-2 ranged from 17% in the South African panel to nearly 70% in panels from Kenya, Uganda, and Zimbabwe. Overall, HerpeSelect was 100% sensitive and 88% specific compared to WB and 100% sensitive and 96% specific compared to the inhibition assay. There was 100% concordance among all three assays for samples from South Africa and Zimbabwe. The discordant results occurred in samples from Kenya and Uganda.

HIV-1 prevalence and herpes simplex virus 2, hepatitis C virus, and hepatitis B virus infections among male workers at a sugar estate in Malawi

HIV-1 prevalence is approximately 23% among men working at a sugar estate in Malawi. Given the scale of the HIV epidemic in this country, it is important to determine possible cofactors of infection. The authors investigated associations between HIV-1 prevalence and herpes simplex virus 2 (HSV-2), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections (indicated by anti-HSV-2, anti-HCV and HBsAg positivity, respectively) in a nested case-control study of 279 HIV-positive and 280 HIV-negative male workers. The prevalence of HSV-2 infection was 88.1% among HIV-positive persons and 64.3% among HIV-negative control subjects (p <.01). This difference persisted after adjusting for sexual behavior and history of sexually transmitted diseases (OR = 4.12; 95% CI, 2.21-7.68). The prevalence of HCV seropositivity was 12.7% among HIV-positive persons and 10.0% among control subjects (p =.31), whereas that of HBV infection was 16.9% among HIV-positive persons and 14.4% among control subjects (p =.46). HSV-2 infection is significantly associated with prevalent HIV-1 infection in this population. Therefore, preventive measures for HSV-2 and HIV infection should be emphasized.

Use of a fragment of glycoprotein G-2 produced in the baculovirus expression system for detecting herpes simplex virus type 2-specific antibodies

Fragments of glycoprotein G (gG-2(281-594His)), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1(t26-189His)), and glycoprotein D of HSV-1 (gD-1(1-313)), were expressed in the baculovirus expression system to develop an assay for the detection of HSV-1 and HSV-2 type-specific antibodies. The expression of the gG-1(t26-189His) and gG-2(281-594His) fragments was analyzed by Western blotting using monoclonal antibodies LP10 and AP1, respectively. The molecular masses of the major products of gG-1(t26-189His) and the fragment of gG-2(281-594His) were 36 to 39 kDa and 64 to 72 kDa, respectively. Human sera positive for HSV-1 reacted with gG-1(t26-189His), sera positive for HSV-2 reacted with the gG-2(281-594His) fragment, and sera positive for both types reacted with gG-1(t26-189His) and gG-2(281-594His) in Western blotting. The human sera recognized polypeptides of gG-2(281-594His) with molecular masses of 57 to 67 and 120 to 150 kDa and additional faint bands of 21, 29, and 45 kDa. The recombinant gG-1(t26-189His) and the recombinant gG-2(281-594His) fragment were used as type-specific antigens for the detection of HSV-1- and HSV-2-specific antibody responses in human sera, respectively. As type-common antigens, an extract of HSV-1-infected Vero cells and recombinant gD-1(1-313) were used. An enzyme-linked immunosorbent assay to detect type-specific antibodies was developed, and the sensitivity and specificity were evaluated by comparison with commercial tests by using sera obtained from different sources. The sensitivity and specificity were 91.5 and 95.5%, respectively, compared to the Gull assay. The gG-2(281-594His) fragment can be obtained in relatively large quantities at low cost.

Sorting out the new HSV type specific antibody tests

This review will delineate performance characteristics and limitations, as far as they are known, of the new glycoprotein G based, type specific HSV serologies. Several of these tests have been FDA approved in the United States for use in adults. With the departure of Gull/Meridian from the HSV serology market, it is important for clinicians to understand the sources and claims of the remaining type specific tests. Moreover, inaccurate tests using crude antigen preparations remain on the market. These tests are identified based on product insert information provided by company representatives.

Comparison of four enzyme immunoassays with a western blot assay for the determination of type-specific antibodies to herpes simplex virus

Most current enzyme immunoassays (EIAs) differentiate inadequately between types 1 and 2 herpes simplex virus (HSV) antibodies since significant cross-reactivity exists. We compared 4 IgG type-specific EIAs using a Western blot assay for resolution of discrepant results. The Diamedix had sensitivities of 100% for types 1 and 2 but specificities of only 71% and 61%, respectively. The cross-reactivity rate was 82% in positive samples tested. For HSV types 1 and 2, the Zeus sensitivities were 92% and 98%, respectively; specificities were 72% and 79%, respectively; the cross-reactivity rate was 54%. For HSV types 1 and 2, the Wampole sensitivities were 98% and 95%, respectively; specificities were 68% and 85%, respectively; the cross-reactivity rate was 47%. For HSV types 1 and 2, the Meridian sensitivities were 98% and 90%, respectively; specificities were 96% and 100%, respectively; no cross-reactivity was found between positive samples tested. While the Diamedix, Zeus, and Wampole assays showed good sensitivity, they lacked type specificity. The Meridian EIA offers the highest specificity along with no observed cross-reactivity. This EIA may be an easier, reliable alternative to Western blot for the determination of HSV type-specific antibodies.