Herpes simplex virus type 2 antibody detection performance in Kisumu, Kenya, using the Herpeselect ELISA, Kalon ELISA, Western blot and inhibition testing

Menstrual cups to reduce bacterial vaginosis and STIs through reduced harmful sexual and menstrual practices among economically vulnerable women: protocol of a single arm trial in western Kenya

BACKGROUND

In western Kenya, menstrual hygiene management (MHM) is a pervasive problem. Challenges are compounded for economically constrained women who continue to engage in sex during menses and resort to practices such as vaginal insertion of tissue and cotton to maintain dryness during sex. These practices can be harmful to the vaginal microbiome (VMB) and can lead to high rates of sexually transmitted infections (STIs) and HIV. This study will evaluate whether menstrual cups that can be worn during intercourse may be beneficial to the VMB and help prevent Bacterial vaginosis (BV) and STI acquisition among these economically vulnerable women.

METHODS

In this single-arm trial among economically vulnerable women in semi-urban western Kenya, we will evaluate the preliminary efficacy of menstrual cups on non-optimal VMB, BV, and STIs, and investigate safety, acceptability, and implementation needs. Through peer referral we aim to recruit 402 menstruating women aged 15-35 who exchange sex for money or basic needs. Women who are pregnant, have delivered in the past six months, or use an intrauterine device (IUD) will not be eligible. Participants will be seen every six months for 24 months and be asked about their sexual and MHM practices, with samples collected to assess BV and VMB. At baseline, 12-, and 24-month visits, additional samples will be collected to measure HIV and STIs (C. trachomatis, N. gonorrhoeae, and T. vaginalis). HSV-2 status will be assessed at baseline. Intervention provision will consist of one reusable disc-shaped menstrual cup per participant and a group-based training within four weeks of the 12-month visit, followed by monthly telephone surveys for the first three months to assess cup use, adverse events, and provide any assistance. Primary analyses of preliminary efficacy will compare probabilities of optimal VMB, BV, and STIs in the pre-intervention period to the post-intervention period. Primary safety analyses will compare occurrence of menstrual toxic shock syndrome and cervicovaginal laceration.

DISCUSSION

If demonstrated safe and effective, this multipurpose reproductive health intervention will offer a dignified solution for the menstrual hygiene needs of women who engage in sex for livelihood and reduce their occurrence of non-optimal VMB, BV, and STIs.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05666778 (28th December, 2022); Pan African Clinical Trials Registry 202,305,912,778,108 (25th May, 2023).

Sexually Transmitted Infection Treatment Guidelines for Adolescent Health Providers: What's New in 2021?

The Centers for Disease Control and Prevention's Sexually Transmitted Infections Treatment Guidelines, 2021 contain new recommendations for the treatment of gonococcal, chlamydial, and trichomonas infections, as well as pelvic inflammatory disease. Providers are encouraged to broaden their screening practices by considering incorporating rectal and pharyngeal testing when indicated, as well as opt-out testing for adolescent females. The discussion of testing and counseling for genital herpes infections has been expanded.

Vaginal and Penile Microbiome Associations with HSV-2 in Women and their Male Sex Partners

Background

We determined how the vaginal and penile microbiomes contribute to herpes simplex virus type 2 (HSV-2) serostatus within sexual partnerships.

Methods

Microbiomes were characterized in cervicovaginal lavage and penile meatal swab specimens through high-throughput 16s ribosomal RNA gene amplicon sequencing. HSV-2 antibody was detected in serum specimens. We modeled vaginal and penile taxa and covariates contributing to HSV-2 status in women and men using bivariate probit analysis.

Results

Among 231 couples, HSV-2 was detected in both partners in 78 couples (33.8%), in the woman only in 52 (22.5%),in the man only in 27 (11.7%), and in neither in 74 (32.0%). Among the women (median age, 22 years) 10.9% had human immunodeficiency virus (HIV), and 21.4% had Bacterial vaginosis. Among men (median age, 26 years), 11.8% had HIV, and 55.0% circumcised. In an analysis with adjustment for sociodemographics and Bacterial vaginosis, enrichment of vaginal Gardnerella vaginalis and Lactobacillus iners was associated with increased likelihood of HSV-2 in both partners. Penile taxa (including Ureaplasma and Aerococcus) were associated with HSV-2 in women.

Conclusions

We demonstrate that penile taxa are associated with HSV-2 in female partners, and vaginal taxa are associated with HSV-2 in male partners. Our findings suggest that couples-level joint consideration of genital microbiome and sexually transmitted infection or related outcomes could lead to new avenues for prevention.

Herpes simplex virus type 2 (HSV-2) IgG index values in two immunoassays in relation to HSV-2 IgG inhibition assay results

CDC guidelines recommend confirmatory testing of sera with low-positive indices (1.10-3.50) in the HerpeSelect® (HSLT) HSV-2 IgG screening assay. To determine if this recommendation is adequate for our patient population, we reviewed HSLT HSV-2 IgG screening indices for 262 screen-positive sera (index >1.10) tested in our confirmatory assay, which assesses inhibition of binding to recombinant gG2 by HSV-1- and HSV-2-infected cell lysates. To determine how the recommendation affects other screening assays, we tested these samples in the Liaison® HSV-2 IgG assay. Of 124 false-positive sera, 20% and 39% had an index >3.50 in the HSLT and Liaison screening assays, respectively. In both assays, 51% of 63 indeterminate sera (inhibition by HSV-1 lysate) had indices >3.50. Similarly, ≥75% of 75 true-positive samples exhibited indices >3.50 in both assays. Thus, confirmatory testing only of sera with low-positive HSV-2 IgG indices misses some false-positive and indeterminate samples, leading to misdiagnosis of HSV-2 infection.

2017 European guidelines for the management of genital herpes

Genital herpes is one of the commonest sexually transmitted infections worldwide. Using the best available evidence, this guideline recommends strategies for diagnosis, management, and follow-up of the condition as well as for minimising transmission. Early recognition and initiation of therapy is key and may reduce the duration of illness or avoid hospitalisation with complications, including urinary retention, meningism, or severe systemic illness. The guideline covers a range of common clinical scenarios, such as recurrent genital herpes, infection during pregnancy, and co-infection with human immunodeficiency virus.

Computational sensing of herpes simplex virus using a cost-effective on-chip microscope

Caused by the herpes simplex virus (HSV), herpes is a viral infection that is one of the most widespread diseases worldwide. Here we present a computational sensing technique for specific detection of HSV using both viral immuno-specificity and the physical size range of the viruses. This label-free approach involves a compact and cost-effective holographic on-chip microscope and a surface-functionalized glass substrate prepared to specifically capture the target viruses. To enhance the optical signatures of individual viruses and increase their signal-to-noise ratio, self-assembled polyethylene glycol based nanolenses are rapidly formed around each virus particle captured on the substrate using a portable interface. Holographic shadows of specifically captured viruses that are surrounded by these self-assembled nanolenses are then reconstructed, and the phase image is used for automated quantification of the size of each particle within our large field-of-view, ~30 mm². The combination of viral immuno-specificity due to surface functionalization and the physical size measurements enabled by holographic imaging is used to sensitively detect and enumerate HSV particles using our compact and cost-effective platform. This computational sensing technique can find numerous uses in global health related applications in resource-limited environments.

Performance of Kalon herpes simplex virus 2 assay using dried blood spots among young women in Uganda

This study evaluated the performance of the Kalon Biological HSV2 IgG enzyme-linked immunosorbent assay (Kalon Biological Ltd, Surrey, United Kingdom) on dried blood spots (DBS) of various dilutions compared with plasma from young women aged 18–24 years in Uganda. We estimated the sensitivity and specificity of three DBS dilutions using plasma as the reference. All three evaluated DBS dilutions yielded low sensitivities and specificities, with DBS 1:2 yielding the highest concurrence. Other herpes simplex virus type 2 assays should be examined with regard to their utility for testing DBS.

Precision of the Kalon Herpes Simplex Virus Type 2 IgG ELISA: an international inter-laboratory assessment

BACKGROUND

The commercial Kalon HSV-2 IgG ELISA is currently recommended for research use in sub-Saharan Africa because of its superior accuracy compared to other serologic assays. However, there are no data on key precision parameters of Kalon such as inter-operator variation, repeatability, and reproducibility, thus contributing to a barrier for its acceptance and use in clinical trials in sub-Saharan Africa. We evaluated the analytical and field precision of the Kalon HSV-2 IgG ELISA.

METHODS

A total of 600 HIV-infected and uninfected serum samples from South Africa and Zambia, previously tested by the gold standard University of Washington HSV western blot (UW-WB), were tested using Kalon by two technologists in an United States reference laboratory. Aliquots of 183 samples were retested using Kalon by an on-site technologist in a South African laboratory and a Zambian laboratory.

RESULTS

Intra-assay variation was below 10 %. Intra-assay, intra-laboratory, and inter-laboratory correlation and agreement were significantly high (p < 0.01). In comparison to the UW-WB, accurate performance of Kalon was reproducible by each operator and laboratory. Receiver operating characteristic curve analysis indicated high selectivity of Kalon in the overall study population (area under the curve = 0.95, 95%CI = 0.92-0.97).

DISCUSSION

Kalon is a robust assay with high precision and reproducibility. Accordingly, operator errorlikely does not contribute to the variability observed in Kalon's specificity throughout sera from sub-Saharan Africa.

CONCLUSIONS

In populations with optimal diagnostic accuracy, Kalon is a reliable stand-alone method for on-site HSV-2 IgG antibody detection.

Disclosure of HSV-2 serological test results in the context of an adolescent HIV prevention trial in Kenya

OBJECTIVES

Herpes simplex virus type 2 (HSV-2) biomarkers are often used in adolescent sub-Saharan HIV prevention studies, but evaluations of test performance and disclosure outcomes are rare in the published literature. Therefore, we investigated the proportion of ELISA-positive and indeterminate samples confirmed by western blot (WB), the psychosocial response to disclosure and whether reports of sexual behaviour and HSV-2 symptoms are consistent with WB confirmatory results among adolescent orphans in Kenya.

METHODS

In 2011, 837 Kenyan orphan youth in grades 7 and 8 enrolled in an HIV prevention clinical trial with HSV-2 biomarker outcomes. We used a modified algorithm for the Kalon HSV-2 ELISA to improve specificity; positive and indeterminate results were WB tested. We developed culturally sensitive protocols for disclosing positive results, and documented psychosocial responses, reports of sexual contact and HSV-2 symptoms.

RESULTS

28 adolescents (3.3%) were identified as HSV-2 seropositive, six as indeterminate. Of these, 22 positive and all indeterminates were WB tested; 20 and 5, respectively, were confirmed positive. Most youth reported moderate brief stress after disclosure; 22% reported longer and more severe distress. Boys were more likely to be in the latter category. Self-reported virginity was highly inconsistent with WB-confirmed positives.

CONCLUSIONS

The higher than manufacturer's cut-off for Kalon ELISA modestly reduced the rate of false-positive test results, but also increased false negatives. Investigators should consider the risk:benefit ratio in deciding whether or not to disclose HSV-2 results to adolescent participants under specific field conditions.

TRIAL REGISTRATION NUMBER

NCT01501864.

Global Diversity within and between Human Herpesvirus 1 and 2 Glycoproteins

Human herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are large-genome DNA viruses that establish a persistent infection in sensory neurons and commonly manifest with recurring oral or genital erosions that transmit virus. HSV encodes 12 predicted glycoproteins that serve various functions, including cellular attachment, entry, and egress. Glycoprotein G is currently the target of an antibody test to differentiate HSV-1 from HSV-2; however, this test has shown reduced capacity to differentiate HSV strains in East Africa. Until the recent availability of 26 full-length HSV-1 and 36 full-length HSV-2 sequences, minimal comparative information was available for these viruses. In this study, we use a variety of sequence analysis methods to compare all available sequence data for HSV-1 and HSV-2 glycoproteins, using viruses isolated in Europe, Asia, North America, the Republic of South Africa, and East Africa. We found numerous differences in diversity, nonsynonymous/synonymous substitution rates, and recombination rates between HSV-1 glycoproteins and their HSV-2 counterparts. Phylogenetic analysis revealed that while most global HSV-2 glycoprotein G sequences did not form clusters within or between continents, one clade (supported at 60.5%) contained 37% of the African sequences analyzed. Accordingly, sequences from this African subset contained unique amino acid signatures, not only in glycoprotein G, but also in glycoproteins I and E, which may account for the failure of sensitive antibody tests to distinguish HSV-1 from HSV-2 in some African individuals. Consensus sequences generated in the study can be used to improve diagnostic assays that differentiate HSV-1 from HSV-2 in global populations.

IMPORTANCE

Human herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are large DNA viruses associated with recurring oral or genital erosions that transmit virus. Up to 12 HSV-1 and HSV-2 glycoproteins are involved in HSV cell entry or are required for viral spread in animals, albeit some are dispensable for replication in vitro. The recent availability of comparable numbers of full-length HSV-1 and HSV-2 sequences enabled comparative analysis of gene diversity of glycoproteins within and between HSV types. Overall, we found less glycoprotein sequence diversity within HSV-2 than within the HSV-1 strains studied, while at the same time, several HSV-2 glycoproteins were evolving under less selective pressure. Because HSV glycoproteins are the focus of antibody tests to detect and differentiate between infections with the two strains and are constituents of vaccines in clinical-stage development, these findings will aid in refining the targets for diagnostic tests and vaccines.

Evaluating HIV Prevention Programs: Herpes Simplex Virus Type 2 Antibodies as Biomarker for Sexual Risk Behavior in Young Adults in Resource-Poor Countries

Background

Measuring effectiveness of HIV prevention interventions is challenged by bias when using self-reported knowledge, attitude or behavior change. HIV incidence is an objective marker to measure effectiveness of HIV prevention interventions, however, because new infection rates are relatively low, prevention studies require large sample sizes. Herpes simplex virus type 2 (HSV-2) is similarly transmitted and more prevalent and could thus serve as a proxy marker for sexual risk behavior and therefore HIV infection.

Methods

HSV-2 antibodies were assessed in a sub-study of 70,000 students participating in an education intervention in Western Province, Kenya. Feasibility of testing for HSV-2 antibodies was assessed comparing two methods using Fisher’s exact test. Three hundred and ninety four students (aged 18 to 22 years) were randomly chosen from the cohort and tested for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Out of these, 139 students were tested for HSV-2 with ELISA and surveyed for sexual risk behavior and 89 students were additionally tested for HSV-2 with a point-of-contact (POC) test.

Results

Prevalence rates were 0.5%, 1.8%, 0.3% and 2.3% for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis, respectively. Prevalence of HSV-2 antibodies was 3.4 % as measured by POC test (n=89) and 14.4 % by ELISA (n=139). Specificity of the POC test compared with ELISA was 100%, and the sensitivity only 23.1%. Associations between self-reported sexual behavior and HSV-2 serostatus could not be shown.

Conclusions

Associations between self-reported sexual risk behavior and HSV-2 serostatus could not be shown, probably due to social bias in interviews since its transmission is clearly linked. HSV-2 antibody testing is feasible in resource-poor settings and shows higher prevalence rates than other sexually transmitted diseases thus representing a potential biomarker for evaluation of HIV prevention interventions.

Prevalence and incidence estimation of HSV-2 by two IgG ELISA methods among South African women at high risk of HIV

Introduction

Previous comparison studies of the Kalon and HerpeSelect 2 ELISA IgG assays on sub-Saharan samples have found differences in the sensitivity and specificity of these assays. Using longitudinal samples from an HIV prevention study, we compared both assays and determined the HSV-2 prevalence and incidence in a South African young female population at elevated risk of acquiring HIV.

Methods

Samples at baseline were tested in both assays using the manufacturers’ guidelines (cut-off > 1.10). When non-reactive in one assay, the final visit samples were tested to determine the incidence rate. Using correlation and regression analyses, the intra- and inter-assay variabilities were assessed.

Results

The prevalence rate was 41.1% and 44.9% for Kalon and HerpeSelect using the manufacturer guidelines, respectively. Agreement between the two tests were high (kappa = 0.92). The original optical density values of both assays were highly correlated (R = 0.94), but the calibrator and correspondingly cut-off index values differed between the assays. Lowering the index value cut-off for the Kalon assay by 40% (to 0.66) resulted in a HSV-2 prevalence of 43.2%, and increased agreement between the assays (to kappa = 0.96). The incidence rate was 16.3/100 Person Years using the lower cut-off for the Kalon assay.

Discussion

In this longitudinal study, we showed that the performance of the two assays was very similar. After lowering the cut-off for the Kalon assay to 0.66 early infections were detected without impairing its specificity. The prevalence and incidence rates are in line with previously described rates for sub-Saharan African cohorts.

Use of HIV and HSV-2 biomarkers in sub-saharan adolescent prevention research: a comparison of two approaches

Self-report of sexual behavior among adolescents is notoriously inconsistent, yet such measures are commonly used as outcomes for human immunodeficiency virus (HIV) prevention intervention trials. There has been a growing interest in the use of HIV and other sexually transmitted disease biomarkers as more valid measures of intervention impact in high HIV prevalence areas, particularly in sub-Saharan Africa. We examine the challenges, benefits, and feasibility of including HIV and herpes simplex virus type 2 (HSV-2) biomarker data, with details about different data collection and disclosure methods from two adolescent prevention trials in Kenya and Zimbabwe. In Kenya, whole blood samples were collected using venipuncture; adult guardians were present during biomarker procedures and test results were disclosed to participants and their guardians. In contrast, in Zimbabwe, samples were collected using finger pricks for dried blood spots (DBS); guardians were not present during biomarker procedures, and results were not disclosed to participants and/or their guardians. In both countries, prevalence in the study samples was low. Although the standard of care for testing for HIV and other sexually transmitted infections includes disclosure in the presence of a guardian for adolescents under age 18, we conclude that more research about the risks and benefits of disclosure to adolescents in the context of a clinical trial is needed. Notably, current serological diagnosis for HSV-2 has a low positive predictive value when prevalence is low, resulting in an unacceptable proportion of false positives and serious concerns about disclosing test results to adolescents within a trial. We also conclude that the DBS approach is more convenient and efficient than venipuncture for field research, although both approaches are feasible. Manufacturer validation studies using DBS for HSV-2, however, are needed for widespread use.

Comparative performance of the Kalon and HerpeSelect enzyme-linked immunosorbant assays to determine the prevalence of herpes simplex virus type 2 in Papua New Guinea

Background Infection with herpes simplex virus type 2 (HSV-2) is common worldwide and an important risk factor for HIV infection. Aetiological diagnosis of HSV-2 is typically determined with the use of commercially available type-specific enzyme-linked immunosorbent assays (ELISAs). This study aimed to determine the prevalence of HSV-2 among people attending sexual health clinics in the Highlands of Papua New Guinea. The study also aimed to compare the performance of two type-specific ELISA assays, the Kalon and HerpeSelect glycoprotein G2 assays, in this context.

METHODS

Participants were recruited as part of a longitudinal sexual health study. Participants attended four appointments over a 12-month period and had blood taken for HSV-2 serology at each time point. Both the Kalon and HerpeSelect assays were performed as per manufacturer's instructions.

RESULTS

A total of 132 participants were tested for HSV-2 using the Kalon and HerpeSelect ELISAs. HSV-2 prevalence was 52% (95% CI, 43-60) and 61% (95% CI, 52-69) with Kalon and HerpeSelect assays respectively. There was high concordance (87%, ?=0.75, P<0.001, n=115) between the two assays at the manufacturer recommended index value cut-offs. For participants with discordant results at baseline, (n=16), three sero-conversions were observed over the 12-month period when sequential sera was tested.

CONCLUSIONS

A high HSV-2 prevalence was observed in this clinic-based population. Our longitudinal data indicate the higher prevalence of HSV-2 detected with the HerpeSelect ELISA was likely due to false positives rather than a higher sensitivity in the early stages of infection.

Incident HSV-2 infections are common among HIV-1-discordant couples

BACKGROUND

The synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) is well known, but lack of knowledge about the epidemiology of HSV-2 acquisition in HIV-1-discordant couples hampers development of HSV-2 prevention interventions that could reduce HIV-1 transmission.

METHODS

HIV-1-discordant couples were enrolled in Nairobi, Kenya, and followed for up to 2 years. HSV-2 status was determined using HerpeSelect HSV-2 ELISA. Correlates of prevalence and incidence were assessed. RESULTS.: Of 469 HIV-1-discordant couples, at baseline, 353 (75.3%) were affected by HSV-2, of which 189 (53.5%) were concordantly HSV-2 seropositive and 164 (46.5%) were HSV-2-discordant. Prevalence was lowest among HIV-1-uninfected men (39.9%) compared to HIV-1-infected women (64.8%), HIV-1-infected men (66.7%), and HIV-1-uninfected women (68.5%). During follow-up, HSV-2 seroincidence was 14.9 per 100 person-years. Incidence was 1.6-fold higher among females compared to males (95% confidence interval [CI], 1.00-2.48) and 2.5-fold higher in HIV-1-infected compared to uninfected women (95% CI, 1.12-5.74). At least 30% of incident HSV-2 infections originated from an outside partner.

CONCLUSIONS

The high HSV-2 prevalence and incidence in HIV-1-discordant couples in sub-Saharan Africa suggest HSV-2 treatment and prevention could be an effective targeted strategy to reduce HSV-2 and HIV-1 transmission in this high-risk population.

Factors associated with herpes simplex virus type 2 incidence in a cohort of human immunodeficiency virus type 1-seronegative Kenyan men and women reporting high-risk sexual behavior

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is an important cause of genital ulcers and can increase the risk for human immunodeficiency virus type 1 (HIV-1) transmission. Our objective was to determine the incidence and correlates of HSV-2 infection in HIV-1-seronegative Kenyan men reporting high-risk sexual behavior, compared with high-risk HIV-1-seronegative women in the same community.

METHODS

Cohort participants were screened for prevalent HIV-1 infection. HIV-1-uninfected participants had regularly scheduled follow-up visits, with HIV counseling and testing and collection of demographic and behavioral data. Archived blood samples were tested for HSV-2.

RESULTS

HSV-2 prevalence was 22.0% in men and 50.8% in women (P < 0.001). HSV-2 incidence in men was 9.0 per 100 person-years, and was associated with incident HIV-1 infection (adjusted incidence rate ratio [aIRR], 3.9; 95% confidence interval [CI], 1.3-12.4). Use of soap for genital washing was protective (aIRR, 0.3; 95% CI, 0.1-0.8). Receptive anal intercourse had a borderline association with HSV-2 acquisition in men (aIRR, 2.0; 95% CI, 1.0-4.1; P = 0.057), and weakened the association with incident HIV-1. Among women, HSV-2 incidence was 22.1 per 100 person-years (P < 0.001 compared with incidence in men), and was associated with incident HIV-1 infection (aIRR, 8.9; 95% CI, 3.6-21.8) and vaginal washing with soap (aIRR, 1.9; 95% CI, 1.0-3.4).

CONCLUSIONS

HSV-2 incidence in these men and women is among the highest reported, and is associated with HIV-1 acquisition. Although vaginal washing with soap may increase HSV-2 risk in women, genital hygiene may be protective in men.

Herpes simplex virus type 2 infection as a biomarker for sexual debut among young people in sub-Saharan Africa: a literature review

Biological markers are needed in order to provide objective measures to validate self-reported sexual behaviour and interpret prevention trial data. In this review, we evaluated herpes simplex type 2 virus (HSV-2), one of the most prevalent sexually transmitted infections in sub-Saharan Africa as a biological marker of sexual debut. Based on our findings, we do not recommend using HSV-2 as a biomarker for sexual debut due to its low transmission probabilities and the fact that HSV-2 prevalence is not 100% among potential sexual partners. We recommend that the validation of alternative biological measures should be prioritized, and included in future studies and trials of interventions to reduce sexual health risk.

Herpes simplex virus type-2 assay specificity and male circumcision to reduce herpes simplex virus type-2 acquisition

Three male circumcision (MC) trials which enrolled over 10,000 men of different ages, settings (urban vs. rural), countries (Uganda, Kenya and South Africa), and which utilized different surgical techniques were consistent in showing a 51–60% in reduction in HIV incidence [1 –5 ], and all three trials reported that MC decreased high-risk human papillomavirus (HR-HPV) prevalence by 32–35% [6 –8 ].

Circumcision status and incident herpes simplex virus type 2 infection, genital ulcer disease, and HIV infection

OBJECTIVE

We assessed the protective effect of medical male circumcision (MMC) against HIV, herpes simplex virus type 2 (HSV-2), and genital ulcer disease (GUD) incidence.

DESIGN

Two thousand, seven hundred and eighty-seven men aged 18-24 years living in Kisumu, Kenya were randomly assigned to circumcision (n=1391) or delayed circumcision (n=1393) and assessed by HIV and HSV-2 testing and medical examinations during follow-ups at 1, 3, 6, 12, 18, and 24 months.

METHODS

Cox regression estimated the risk ratio of each outcome (incident HIV, GUD, HSV-2) for circumcision status and multivariable models estimated HIV risk associated with HSV-2, GUD, and circumcision status as time-varying covariates.

RESULTS

HIV incidence was 1.42 per 100 person-years. Circumcision was 62% protective against HIV [risk ratio=0.38; 95% confidence interval (CI) 0.22-0.67] and did not change when controlling for HSV-2 and GUD (risk ratio=0.39; 95% CI 0.23-0.69). GUD incidence was halved among circumcised men (risk ratio=0.52; 95% CI 0.37-0.73). HSV-2 incidence did not differ by circumcision status (risk ratio=0.94; 95% CI 0.70-1.25). In the multivariable model, HIV seroconversions were tripled (risk ratio=3.44; 95% CI 1.52-7.80) among men with incident HSV-2 and seven times greater (risk ratio=6.98; 95% CI 3.50-13.9) for men with GUD.

CONCLUSION

Contrary to findings from the South African and Ugandan trials, the protective effect of MMC against HIV was independent of GUD and HSV-2, and MMC had no effect on HSV-2 incidence. Determining the causes of GUD is necessary to reduce associated HIV risk and to understand how circumcision confers protection against GUD and HIV.

Prevalence of herpes simplex virus type 2 infection, human immunodeficiency virus/herpes simplex virus type 2 coinfection, and associated risk factors in a national, population-based survey in Kenya

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is a known biologic cofactor for human immunodeficiency virus (HIV) transmission and acquisition. The Kenya AIDS Indicator Survey 2007 provided Kenya's first nationally representative estimate of HSV-2 prevalence and risk factors.

METHODS

KAIS was a household serosurvey among women and men aged 15 to 64 years. The survey included a behavioral interview and serum testing for HSV-2, HIV, and syphilis infections. Results were weighted for sampling design and nonresponse.

RESULTS

Of 19,840 eligible individuals, 90% completed an interview and 80% consented to testing. In all, 35% were infected with HSV-2, of which 42% were women and 26% were men. Between 15 and 24 years of age, HSV-2 prevalence increased from 7% to 34% in women and 3% to 14% in men. Among couples, 30% were HSV-2 concordant-positive, 21% were discordant, and 49% were concordant-negative. In all, 81% of HIV-infected persons were coinfected with HSV-2. HIV prevalence was 16% among those with HSV-2 and 2% among those without HSV-2. Women with circumcised partners had an HSV-2 prevalence of 39% compared to 77% of women with uncircumcised partners.

CONCLUSIONS

One-third of Kenyans were HSV-2 infected. HIV-1 infection, age, female sex, and lack of male circumcision were population-level predictors for HSV-2 infection. Targeted prevention interventions are needed, including an effective vaccine.

European guideline for the management of genital herpes, 2010

This is the guideline for genital herpes simplex virus (HSV) management for the IUSTI/WHO Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of genital HSV infection. They include details on the management of HSV in pregnancy, those who are immunocompromised and the clinical investigation and management of suspected HSV-resistant disease.

Association between HSV1 seropositivity and obesity: data from the National Health and Nutritional Examination Survey, 2007-2008

Background

Herpes simplex virus (HSV) is among the most common sexually transmitted pathogens in the United States and worldwide. HSV has a high incidence of undetected cases. In addition, there is no treatment, and there is a lack of knowledge why disparities among populations exist. Research studies suggest that fat tissue may participate in body's immune responses, and the impact of obesity on susceptibility to HSV1 infection is not clear. The purpose of this study was to examine whether obesity is a risk factor for HSV1 infection using a large sample from the general population.

Methods/Principal Findings

This cross-sectional study used data from the National Health and Examination and Nutritional Examination Survey (NHANES) from 2007–2008. Variables, gender, age, race/ethnicity, marital status, education, poverty level, and diabetes represented potential confounders and were included in analyses. The two-tailed Pearson's chi square, student's t test, and a multiple logistic regression analysis were applied to evaluate associations using a significance value of p≤0.05. Adjusted odds ratios with 95% confidence interval represented the degree of these associations. The prevalence of HSV1 infection in US population between 20 and 49 years old was 60.3% (n = 1,536). In this study, having a BMI classified as the obese group (BMI 30–39.9) was significantly associated with HSV1 infection before [unadjusted OR = 1.74 (95% CI 1.20–2.51), p = 0.006] and after controlling for socio-demographic factors [adjusted OR = 1.50 (95%CI 1.06–2.13)], p = 0.026]. This association was stronger than three already established risk factors of age, female gender, and poverty level.

Conclusions/Significance

This study provides evidence that obesity may play a role in the susceptibility to HSV1 infection. Findings from this study suggest that obesity should be considered when designing preventive measures for HSV1 infection. These results may also explain why some people acquire HSV1 infections and some do not. Further, these findings may justify an increased emphasis on the control and prevention of HSV1 transmission and other pathogens in overweight and obese populations.

Performance of commercial herpes simplex virus type-2 antibody tests using serum samples from Sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Several commercial type-specific serologic tests are available for herpes simplex virus type 2 (HSV-2). Poor specificity of some tests has been reported on samples from sub-Saharan Africa.

METHODS

To summarize the performance of the tests using samples from sub-Saharan Africa, we conducted a systematic review of publications reporting performance of commercially available HSV-2 tests against a gold standard (Western Blot or monoclonal antibody-blocking EIA). We used random-effects meta-analyses to summarize sensitivity and specificity of the 2 most commonly evaluated tests, Kalon gG2 enzyme-linked immunosorbent assay (ELISA), and Focus HerpeSelect HSV-2 ELISA.

RESULTS

We identified 10 eligible articles that included 21 studies of the performance of Focus, and 12 of Kalon. The primary analyses included studies using the manufacturers' cut-offs (index value = 1.1). Focus had high sensitivity (random effects summary estimate 99%, 95% confidence interval [CI]: 99%-100%) but low specificity (69%, 95% CI: 59%-80%). Kalon had sensitivity of 95% (95% CI: 93%-97%) and specificity of 91% (95% CI: 86%-95%). Specificity of Focus was significantly lower (P = 0.002) among HIV-positive (54%, 95% CI: 40%-68%) than HIV-negative individuals (69%, 95% CI: 56%-82%). When the cut-off optical density index was increased above the recommended value of 1.1 to between 2.2 and 3.5, the specificity of Focus increased to 85% (95% CI: 77%-92%).

CONCLUSIONS

Sensitivity and specificity of HSV-2 tests used in sub-Saharan Africa vary by setting, and are lower than reported from studies in the United States and Europe. Increasing the cut-off optical density index may improve test performance. Evaluation of test performance in a given setting may help deciding which test is most appropriate.

Sensitivity and specificity of herpes simplex virus-2 serological assays among HIV-infected and uninfected urban Ugandans

Herpes simplex virus type 2 (HSV-2) is a risk factor for HIV-1 infection. We characterized HSV-2 serology assay performance in HIV-positive and HIV-negative Africans. Serostatus for HSV-2 and HIV-1 was determined in 493 serum specimens stored from a community HSV-2 prevalence survey in Kampala, Uganda. HSV-2 serology by Focus HerpeSelect ELISA, Biokit HSV-2 rapid assay and Kalon HSV-2 was compared with HSV-2 Western blot (WB) according to HIV-1 serostatus. Sensitivity/specificity was: 99.5%/70.2% for Focus, 97.0%/86.4% for Biokit and 97.5%/96.2% for Kalon. Focus with Biokit confirmation improved sensitivity/specificity (99.4%/96.8%, respectively). Use of a higher Focus index value cut-off of 2.2 instead of 1.1 increased specificity from 70.2% to 92.4%. Kalon had higher specificity than Focus (P < 0.001). Of commercially available HSV-2 serological assays, Kalon alone, or Focus ELISA followed by Biokit confirmation perform best. Improved HSV-2 assays are needed for HSV-2 and HIV-1 public health activities in Africa.

Performance of the Focus HerpeSelect-2 enzyme immunoassay for the detection of herpes simplex virus type 2 antibodies in seven African countries

OBJECTIVE

To compare the performance of the Focus HerpeSelect-2 enzyme immunoassay (EIA) with the gold standard herpes simplex virus (HSV) type 2 western blot, among HIV-1-uninfected men and women in east and southern Africa.

METHODS

3399 HIV-1-uninfected women and men from seven countries in east and southern Africa were tested for HSV-2 antibody using the Focus HerpeSelect-2 EIA. The performance of the HerpesSelect-2 EIA was compared with the gold standard HSV-2-specific western blot.

RESULTS

Two-thirds (2294/3399) of participants were male and two-thirds (2242/3399) were from east Africa. By western blot testing, HSV-2 prevalence was 68%; 59% in men and 85% in women. At the manufacturer's recommended cut-off value of greater than 1.1, the HerpeSelect-2 EIA had a sensitivity of 98.3% and specificity of 80.3%. Receiver operating characteristic plot analysis indicated that the optimum cut-off was 2.1 or greater, with sensitivity 93.9% and specificity 90.5%. Diagnostic accuracy was modestly higher for southern Africa (area under the curve (AUC) 0.979, 95% CI 0.970 to 0.988) compared with east Africa (AUC 0.954, 95% CI 0.942 to 0.965; p<0.001 for southern vs east Africa).

CONCLUSIONS

The Focus HerpeSelect-2 EIA has acceptable diagnostic accuracy for the determination of HSV-2 serostatus in African HIV-1-uninfected adults. An assay cut-off value of 2.1 or greater results in approximately 90% sensitivity and specificity, against a gold standard HSV-2 western blot. Diagnostic accuracy differed slightly by geographical region.

Type-specific herpes simplex virus-1 and herpes simplex virus-2 seroprevalence in Romania: comparison of prevalence and risk factors in women and men

OBJECTIVE

To determine herpes simplex virus (HSV)-2 and HSV-1 seroprevalence in women and men in Romania.

METHODS

A cross-sectional seroprevalence survey was conducted between 2004 and 2005 on a total of 1058 women and men representative of the population of Bucharest. All participants were aged 15-44 years and completed a structured questionnaire. A blood sample was collected to detect IgG anti-HSV-1 and HSV-2 serum antibodies using the HerpeSelect ELISA (Focus Diagnostics).

RESULTS

A total of 761 women (median age 29 years) and 297 men (median age 29 years) were included. Overall, HSV-2 seroprevalence (15.2%) increased with age. Among women, HSV-2 seroprevalence increased from 11.0% in 15-19-year-olds to 38.3% in 40-44-year-olds. Among men, seroprevalence increased from 4.0% in 20-24-year-olds to 27.1% in 40-44-year-olds. HSV-2 seroprevalence was significantly higher among women than men (17.0% vs. 10.8%). HSV-1 seropositivity was high (87.2%) in all age groups, with no clear trend by age or by sex. In addition to older age and female sex, risk factors for HSV-2 included greater number of lifetime sexual partners, lower educational attainment, and history of genital vesicles. Lower educational level and rural residence were associated with a higher risk of HSV-1 seropositivity.

CONCLUSIONS

In Romania, HSV-2 seroprevalence was higher in women than men, and was within European limits and lower than that in Africa and the USA. In contrast, HSV-1 seroprevalence was generally higher than that previously recorded in similarly aged populations in Western Europe.

Performance of HSV-2 type specific serological tests in men in Kenya

This study compared five serological tests with Western blot from University of Washington to determine the most accurate method for detecting antibodies to herpes simplex virus type 2 (HSV-2) in a male population in Kisumu, Kenya. A random sample of 250 fishermen from 18 beaches along Lake Victoria underwent serological testing by two generations of the HerpeSelect HSV-2 ELISA ("Focus Gen 1" and "Focus Gen 2"), Kalon HSV-2 ELISA ("Kalon"), Biokit HSV-2 Rapid Test ("Biokit"), and HerpeSelect Express Rapid HSV-2 ("Express") against the Western blot test ("WB") as the "gold standard". Sensitivity and specificity of tests in this population with a high prevalence of HSV-2 (58% by WB) were: Focus Gen 1: 98.6% and 63.5%; Focus Gen 2: 99.3% and 52.3%; Biokit: 66% and 90.9%; Express: 99.3% and 44.3% and Kalon: 98.6% and 85.7%. Increasing the positive cut-off value improved the specificity of the Focus Gen 2-84.9% and Kalon to 92.2%. Focus Gen 2 offered no improvement in specificity over that of Focus Gen 1. Neither rapid assay could be recommended as either a stand-alone assay or as a confirmatory test. The results of Kalon using a cut-off of 1.5 were the most concordant with those of WB for all the approaches tested. However, low positive Kalon test results should be interpreted with caution as they could reflect early seroconversion or false positive results.

Comparison of focus HerpesSelect and Kalon HSV-2 gG2 ELISA serological assays to detect herpes simplex virus type 2 antibodies in a South African population

INTRODUCTION

Sero-epidemiological studies of herpes simplex virus (HSV) type 2 infection in Africa remain difficult to interpret as a result of the high rate of false-positive results observed when using the new recombinant gG2 HSV-2 ELISA tests. The performance of two widely used gG2 ELISA was compared to derive an appropriate testing algorithm for use in South Africa.

METHODS

Sera from 210 women attending family planning clinics in Johannesburg were tested using HerpeSelect and Kalon HSV-2 gG2 assays. Sera from 20 discordant pairs, 44 concordant positive and 33 concordant negative samples were further tested by HSV Western blot. The sensitivity and specificity of each test and of combination algorithms compared with Western blot were calculated.

RESULTS

HerpeSelect had a sensitivity of 98% (95% CI 95 to 100) and specificity of 61% (95% CI 48 to 74). Kalon was less sensitive (89%, 95% CI 83 to 94) but more specific (85%, 95% CI 61 to 100). Seroprevalence may have been overestimated by as much as 14% by HerpeSelect. Specificity was improved by raising the cut-off index for the determination of a positive result for HerpeSelect (to >or=3.5), but not for Kalon. HIV-1 infection reduced the specificity of HerpeSelect to 30%. Improved sensitivity and specificity were obtained by a two-test algorithm using HerpeSelect (>or=3.5) as the first test and Kalon to resolve equivocal results (sensitivity 92%, 95% CI 82 to 98; specificity 91%, 95% CI 79 to 98).

CONCLUSION

Newer HSV-2 serological tests have low specificity in this South African population with a high HIV-1 prevalence. Two-step testing strategies could provide rational testing alternatives to Western blot.