Time course of seroconversion by HerpeSelect ELISA after acquisition of genital herpes simplex virus type 1 (HSV-1) or HSV-2

Primary herpes simplex virus type-2 infection as a cause of liver failure after liver transplantation

We report a case of fatal primary herpes simplex virus type-2 (HSV-2) infection following liver transplantation, which manifested with fever and liver failure in the absence of muco-cutaneous disease. The infection was characterized by high levels of HSV DNA in blood and the patient's inability to mount HSV-specific T-cell responses while showing preserved T-cell responses against cytomegalovirus. The donor was HSV-1 immunoglobulin G (IgG) seronegative and HSV-2 IgG seropositive, whereas the recipient was HSV-1 and HSV-2 IgG seronegative, suggesting that the graft may have been the source of the infection. In HSV-seronegative recipients of grafts from HSV-seropositive donors, HSV infection should be included in the differential diagnosis of a febrile illness, regardless of the absence of muco-cutaneous disease. In this setting, real-time polymerase chain reaction applied to blood samples provides a sensitive, rapid, and quantitative diagnostic tool.

Prevalence of herpes simplex virus types 1 and 2 among children and adolescents attending a sexual abuse clinic

BACKGROUND

Children and adolescents with a history of sexual abuse are at risk for acquiring herpes simplex virus (HSV) type 2. We evaluated the prevalence of HSV-1 and HSV-2 and the usefulness for this population of 2 commercially available tests.

METHODS

Sera from 150 children seen in a sexual abuse clinic were analyzed for type-specific HSV antibodies using Focus HerpeSelect HSV-2 ELISA (Focus), Biokit HSV-2 Rapid Test (Biokit), and by Western blot (WB).

RESULTS

The patient sample was 81% female, had a mean age of 11.6 years (range, 1 to 18 years), and was 46% Caucasian, 28% Hispanic, 25% African American, and 2% other. According to WB, 77 (51%) of the children were HSV-1 seropositive. For HSV-2, there was 1 "true positive" (positive by all 3 tests) and 1 patient whose serum had atypical HSV-2 bands by WB but was positive by Focus. There were 6 sera that were positive by Focus and negative by WB. Index values of these 6 Focus tests were not predictive of WB status. For the 105 samples for which Biokit data were available, all samples were concordant with WB.

CONCLUSIONS

The findings of this study suggest that routine screening for HSV-2 in sexually abused children does not have a high yield. The Focus test has an unacceptably high rate of false-positive results in children; however, Biokit may be an acceptable substitute for WB in evaluating children for HSV-2 antibodies.

Mature glycoprotein g presents high performance in diagnosing herpes simplex virus type 2 infection in sera of different tanzanian cohorts

Herpes simplex virus type 2 (HSV-2) is a common sexually transmitted infection in sub-Saharan Africa. Glycoprotein G (gG) of HSV-2 elicits a type-specific antibody response and is widely used for serodiagnosis. gG is cleaved into a secreted portion (sgG-2) and a highly O-glycosylated mature portion (mgG-2). The performances of these two native immunosorbent purified antigens were compared in an enzyme-linked immunosorbent assay (ELISA) format with a commercially available assay (FOCUS2) using sera from blood donors (n = 194) and individuals (n = 198) with genital ulcer disease (GUD) from Tanzania. Discordant results were resolved by Western blotting. The HSV-2 seroprevalence for blood donors was estimated as 42%, and that for the GUD cohort was estimated as 78%. The prevalence increased significantly with age for both cohorts and was higher among human immunodeficiency virus (HIV)-positive individuals than among HIV-negative subjects. In the GUD cohort with a high HSV-2 prevalence, all three assays showed statistically similar performances, with sensitivities between 97% and 99% and specificities in the range of 86% to 91%. In contrast, among blood donors with a lower seroprevalence, the mgG-2-based ELISA presented significantly higher specificity (97%) than the sgG-2 ELISA (89%) and FOCUS2 (74%). Overall, the mgG-2 ELISA gave a high performance, with negative and positive predictive values of 96% for blood donors and a negative predictive value of 95% and a positive predictive value of 97% for the GUD cohort. We conclude that native purified mgG-2 showed the highest accuracy for detection of HSV-2 in patient sera from Tanzania and is therefore suitable for seroprevalence studies as well as in clinical settings.

Incidence and Prevalence of Herpes Simplex Virus Infections in Adolescent Women

OBJECTIVES

We conducted this study to examine the incidence, prevalence, and risk factors for herpes simplex virus (HSV) 1 and HSV 2 infection in a cohort of young women who were closely followed for acquisition of sexually transmitted infections.

STUDY DESIGN

Women between the ages of 14 and 18 years had blood and genital specimens obtained quarterly to test for incident sexually transmitted infections. Subjects also had 2 12-week periods each year when they kept a detailed behavioral diary and performed weekly vaginal swabs. Serum specimens were tested for HSV 1 and HSV 2 antibody, and genital specimens were tested for HSV DNA by PCR.

RESULTS

A total of 100 subjects enrolled and had at least 2 sera that could be analyzed for seroconversion. The mean age of the subjects was 15.8 years at entry. The HSV 1 and HSV 2 seroprevalence at entry was 59.6% and 13.5%, respectively. During the study, 4 subjects acquired HSV 1 antibody and 7 acquired HSV 2 antibody, but there were no cases of symptomatic HSV infection identified. The annualized incidence among susceptible individuals was 8.9% for HSV 1 and 7.4% for HSV 2. Three of the 7 HSV 2 sero-converters had HSV 2 DNA detected in vaginal swabs. Age, duration of sexual activity, and the presence of other sexually transmitted infections were predictors of HSV 2 antibody positivity.

CONCLUSIONS

Acquisition of HSV 1 and HSV 2 is relatively common in adolescent women, although symptomatic infection is uncommon. HSV 2 is shed in the genital tract despite the lack of symptoms.

Maternal herpes simplex virus antibody avidity and risk of neonatal herpes

OBJECTIVE

The objective of the study was to assess whether herpes simplex virus antibody avidity is associated with risk of transmission of herpes simplex virus to the neonate.

STUDY DESIGN

We developed a novel herpes simplex virus type 1 avidity test based on the commercially available Focus HerpeSelect-1 enzyme-linked immunosorbent assay kit using sera from nonpregnant subjects with genital herpes simplex virus-1 infection. We used this test, and the previously developed herpes simplex virus type 2 avidity test, to compare maternal herpes simplex virus-1 and herpes simplex virus-2 antibody avidity in women who transmitted herpes simplex virus to the neonate and women who had herpes simplex virus isolated from genital secretions at delivery but who did not transmit herpes simplex virus to their infants.

RESULTS

Among nonpregnant subjects with genital herpes simplex virus-1 infection whose sera were used to develop the herpes simplex virus-1 avidity test, a significant relationship between herpes simplex virus-1 antibody avidity and time since herpes simplex virus-1 acquisition was observed (P < .001, mixed-effects model), with median avidity values increasing over time after primary infection. Among pregnant, herpes simplex virus-1, or herpes simplex virus-2 seropositive women, 4 of 8 women (50%) with avidity 40 or greater transmitted herpes simplex virus to the neonate, compared with only 12 of 97 (12%) of women with avidity greater than 40 (P = .02).

CONCLUSIONS

Herpes simplex virus-1 antibody avidity increased over time after genital herpes simplex virus-1 acquisition, as has been previously observed for herpes simplex virus-2. Among women with herpes simplex virus antibody at delivery, low antibody avidity was associated with herpes simplex virus transmission to the neonate and may be a useful marker for recent seroconversion.

Clinical correlates of index values in the focus HerpeSelect ELISA for antibodies to herpes simplex virus type 2 (HSV-2)

BACKGROUND

Clinical correlates of HerpeSelect ELISA index values are poorly understood.

OBJECTIVES

This study was designed to determine the effects of time of infection, test variability, and antibody avidity on index values.

STUDY DESIGN

Sera (N=313) from 81 patients with new HSV-2 infections and 236 sera from 32 patients with long-standing (median 11.3 years) HSV-2 were tested by HerpeSelect HSV-2 ELISA. High positive, low positive and negative controls were run on 42 test plates to establish test variability.

RESULTS

Index values tended to rise after infection, peaking a median of 9-10 weeks post-infection (range 8-323 days). Of 32 patients with established HSV-2 infections, 7 (22%) had at least one low index value (>1.1 to < or =3.5), and one had a transient seroreversion event. Test variability of index values was substantially lower than inter- or intra-patient variability. Median antibody avidity was higher in sera with high versus low index values in established infections, but unrelated to index value in patients with early infections.

CONCLUSIONS

Index values or index value changes are not absolute indicators of early versus established HSV-2 infection or solely a function of test variability. Low antibody avidity may contribute to low index values once infection is established.

Performance of a novel test for IgM and IgG antibodies in subjects with culture-documented genital herpes simplex virus-1 or -2 -infection

Novel tests (BioPlex) for herpes simplex virus-1 (HSV-1) and HSV-2 IgG were compared with HerpeSelect HSV-1 and HSV-2 ELISAs for type-specific IgG. The sensitivity and specificity of BioPlex HSV-1 IgG were 94% (84/89) and 96% (119/124), respectively, with unselected sera, while the sensitivity and specificity of BioPlex HSV-2 IgG were 92% (109/118) and 98% (95/97), respectively. BioPlex IgM was compared with Diamedix IgM against sera from patients with culture-documented genital herpes. The test results were concordant in 81% of sera from HSV-1 patients and in 90% of sera from HSV-2 patients. Use of BioPlex IgM in addition to BioPlex IgG tests increased HSV-2 seroconversion detection from 47% of subjects to 70%. Use of Diamedix IgM in addition to Focus IgG ELISA increased HSV-2 detection from 40% of subjects to 70%. IgM was detected by BioPlex in 63% of sera from patients with early HSV-2 infection (< 30 days) and in 59% of sera by Diamedix. IgM was also detected in a large proportion of sera from subjects with established HSV-2 infection (33% by BioPlex and 29% by Diamedix). Addition of IgM testing substantially increased the ability to detect seroconversion early in infection. IgM is an indicator of recent infection only in subjects who lack detectable IgG.

Use of "biokit HSV-2 Rapid Assay" to improve the positive predictive value of Focus HerpeSelect HSV-2 ELISA

BACKGROUND

Commercially available assays to detect antibodies to the herpes simplex virus type 2 (HSV-2)-specific glycoprotein gG-2 have markedly improved serologic diagnosis of HSV-2 infection. However, even tests with high specificity can have low positive predictive values in low prevalence populations. HSV-2 is a chronic, life-long viral infection that requires both medical attention and potential alterations in health care strategy. As such, the concern for false positive diagnoses is high confirmatory testing is routine for other viral serologies such as HIV and hepatitis C. We evaluated such a strategy for HSV-2 serology by using an easily performed commercial test, biokitHSV-2 rapid test ("Biokit"; Biokit USA, Lexington MA) as a confirmatory test for the widely used gG-2 specific serology ("Focus;" HerpeSelect HSV-2 ELISA; Focus Diagnostics, Cypress CA).

METHODS

We tested 782 sera by Focus HSV-2 ELISA, Biokit, and the current gold standard test, Western blot (WB).

RESULTS

The positive predictive value of the Focus HSV-2 ELISA increased from 80.5% to 95.6% when Biokit testing was performed on sera that were initially positive by Focus HSV-2 ELISA. Confirmatory testing increased the specificity markedly among sera with Focus EIA values between 1.1 and 3.5: only 35% of low positive (index values 1.1-3.5) Focus HSV-2 ELISA results confirmed as positive by Biokit and WB compared with 92% of those with index values >3.5. Mathematical modeling of the data resulted in expected positive predictive values over 98% for populations with antibody prevalences typical of clinical practices in the US and Europe.

CONCLUSION

Confirmatory Biokit testing of positive Focus HSV-2 ELISA results is fast, easy, and effective in reducing falsely positive HSV-2 antibody results. Patients, clinicians, and laboratories could benefit from the enhanced specificity of this simple HSV-2 serologic test combination.

The epidemiology of genital infection with herpes simplex virus types 1 and 2 in genitourinary medicine attendees in inner London

OBJECTIVE

To characterise the epidemiological and clinical features of genital herpes and the diagnostic role of HSV-2 specific serology in an ethnically diverse cohort of genitourinary medicine (GUM) attendees in inner London.

METHODS

Genital swabs (n = 186) were tested by real time polymerase chain reaction (PCR) and serum samples (n = 70) by HSV-2 specific enzyme linked immunoassay (ELISA).

RESULTS

Among 186 patients (median age 29 years), 104/186 (56%) were male and 176/186 (95%) heterosexual; ethnicity was predominantly black Caribbean (76/186, 41%), white (65/186, 35%), or black-African (41/186, 22%). The most common lesion sites were penis (85/104 men, 82%) and vulva (63/82 women, 77%); 114/186 (61%) patients were diagnosed clinically with first episode disease. Women were more likely to present <5 days of onset (p = 0.008). Black Caribbean patients were more likely to present > or = 5 days (p = 0.04) and decline HIV testing (p = 0.03). By PCR, 108/186 (58%) swabs tested positive for HSV-1 (7/108, 6.5%) or HSV-2 (101/108, 93.5%). Independent predictors of a positive PCR were heterosexual group, <5 days of onset, and visible genital ulceration on examination. HSV-2 was associated with black Caribbean and black African ethnicity; HSV-1 with white ethnicity (p = 0.006). By HSV-2 specific serology, 16/42 (38%) first episodes caused by HSV-2 were recurrent infections, and 7/19 (37%) patients with recurrent genital disease but negative PCR had genital herpes.

CONCLUSIONS

Epidemiological trends in genital HSV-1 and HSV-2 infection appear to vary between ethnic groups in the United Kingdom. HSV-2 specific serology improves diagnostic accuracy in GUM populations where most genital infections are caused by HSV-2.

Recommendations for the selective use of herpes simplex virus type 2 serological tests

BACKGROUND

Herpes simplex virus (HSV) type-specific serological tests are now widely available, but indications for their use have not been well defined. The California Sexually Transmitted Diseases (STD) Controllers Association convened a committee of clinicians and researchers to make recommendations for the use of type-specific HSV type 2 (HSV-2) serological tests.

METHODS

By means of a systematic review of the literature, evidence to support screening in selected high-risk groups was compiled. Screening recommendations were developed by applying standard screening criteria to each specific population.

RESULTS

The committee concluded that, in addition to serological testing for the diagnostic evaluation of patients with symptoms, screening of asymptomatic patients is likely to be beneficial among the following groups: those at high risk for STDs and human immunodeficiency virus (HIV) infection who are motivated to reduce their sexual risk behavior, HIV-infected patients, and patients with sex partners with genital herpes. In contrast, universal screening for HSV-2 infection in pregnant women is unlikely to be beneficial.

CONCLUSIONS

The targeted use of HSV-2 serological tests for specific diagnostic situations and selected populations should benefit patients, providers, and the community. Until more data become available, these recommendations provide justification for selective diagnostic and screening uses of HSV-2 serological tests.

Development and use of a type-specific antibody avidity test based on herpes simplex virus type 2 glycoprotein G

OBJECTIVES

It is difficult to discriminate between lesions resulting from recently acquired versus established genital herpes simplex virus type 2 (HSV-2) infection. Methods not based on history or serum IgM status are needed.

GOAL

Our goal was to use type-specific gG-2 antibody avidity determinations based on HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA) to identify new infections.

STUDY

Sera (N = 168) from 71 patients with first-episode genital herpes and 45 sera from 21 patients with recurrent episodes were tested.

RESULTS

Median avidity increased from 30.2 in sera drawn </=6 weeks to 54.9 >6 weeks after infection (P <0.001). Patients with recurrent episodes and established HSV-2 infections (median, 6.1 years' duration) had higher avidity antibodies (median, 92.7; range, 55.1-100) than patients after first episodes (median, 33.7; range, 6.4-73.9; P <0.001).

CONCLUSION

Avidity testing based on HerpeSelect ELISA could be a cost-effective method to identify patients with new HSV-2 infections.

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.

Living with genital herpes: how effective is antiviral therapy?

Twenty-five percent of American women and 20% of American men have genital herpes. Most of these individuals have never been diagnosed because of the prevalence of atypical clinical presentation and subclinical infection. This chronic, recurrent infection poses a significant public health challenge, particularly in women of childbearing age, who are at risk of transmitting the virus to their infants during pregnancy and birth, as well as to their discordant sexual partners. Antiviral therapy decreases the rate of recurrent episodes, decreases asymptomatic shedding of the virus, reduces the risk of transmission to sexual partners, and reduces the rate of operative delivery in women with a history of genital herpes. This article reviews the literature to explore evidence-based strategies for addressing the physical and psychological sequelae of herpes simplex virus infection and for accurately diagnosing and managing neonates who acquire this infection perinatally.

Performance of the focus and Kalon enzyme-linked immunosorbent assays for antibodies to herpes simplex virus type 2 glycoprotein G in culture-documented cases of genital herpes

Glycoprotein G-based herpes simplex virus type 2 (HSV-2) enzyme-linked immunosorbent assays from Focus and Kalon were performed with specimens from 118 patients with culture-documented genital herpes episodes, and their results were compared. Sensitivity was 52% by Kalon and 86% by Focus for first HSV-2 episodes and 100% (for each of the two tests) for recurrent HSV-2. Median times to seroconversion were 120 days by the Kalon assay, 21 days by the Focus assay, and 68 days by Western blotting assay. Values for specificity were 100% (Kalon) and 93% (Focus).

Association between acquisition of herpes simplex virus type 2 in women and bacterial vaginosis

A longitudinal cohort study of sexually active women 18-30 years of age was conducted to identify variables associated with the acquisition of herpes simplex virus type 2 (HSV-2) infections. Six hundred seventy HSV-2-seronegative women were followed up at 4-month intervals for 1 year; acquisition of HSV-2 antibodies was detected in 32 of these women. Black race, < or =12 years of education, having a new sex partner, and bacterial vaginosis (BV) were associated with HSV-2 seroconversion on univariate analysis. Antecedent HSV-1 infection was not protective against HSV-2 acquisition. After controlling for other identified risk factors in multivariable models, the diagnosis of BV remained associated with an increased risk of acquiring HSV-2 infection (hazard ratio, 2.1; 95% confidence interval, 1.0-4.5; P=.05). In this study, the population attributable risk of BV for HSV-2 seroconversion was 21%. Additional studies are needed to determine whether screening and treatment of BV could reduce susceptibility to the acquisition of HSV-2 in women.