New concepts in understanding genital herpes

Gene editing for latent herpes simplex virus infection reduces viral load and shedding in vivo

Anti-HSV therapies are only suppressive because they do not eliminate latent HSV present in ganglionic neurons, the source of recurrent disease. We have developed a potentially curative approach against HSV infection, based on gene editing using HSV-specific meganucleases delivered by adeno-associated virus (AAV) vectors. Gene editing performed with two anti-HSV-1 meganucleases delivered by a combination of AAV9, AAV-Dj/8, and AAV-Rh10 can eliminate 90% or more of latent HSV DNA in mouse models of orofacial infection, and up to 97% of latent HSV DNA in mouse models of genital infection. Using a pharmacological approach to reactivate latent HSV-1, we demonstrate that ganglionic viral load reduction leads to a significant decrease of viral shedding in treated female mice. While therapy is well tolerated, in some instances, we observe hepatotoxicity at high doses and subtle histological evidence of neuronal injury without observable neurological signs or deficits. Simplification of the regimen through use of a single serotype (AAV9) delivering single meganuclease targeting a duplicated region of the HSV genome, dose reduction, and use of a neuron-specific promoter each results in improved tolerability while retaining efficacy. These results reinforce the curative potential of gene editing for HSV disease.

Resorbable nanofibrous membranes for local and sustained co-delivery of acyclovir and ketorolac in herpes therapy

Herpes simplex and herpes zoster are both viral infections caused by members of the herpesvirus family. The former is characterized by painful, fluid-filled blisters or sores on the skin and mucous membranes, while the latter presents as a painful rash with blisters, typically occurring in a single band or patch along one side of the body. The treatment remains a challenge since current antiviral therapy via oral administration may lead to unfavorable side effects such as headaches, nausea, and diarrhea. This study used electrospinning to develop biodegradable nanofibrous poly(lactic-co-glycolic acid) (PLGA) membranes for delivery of both acyclovir and ketorolac. The structure of the spun nanofibers was assessed via scanning electron microscopy (SEM), and the appearance of loaded acyclovir and ketorolac in the nanofibers was confirmed with Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Release profiles of these drugs from the nanofibrous membranes were assessed using in vitro elution studies, high-performance liquid chromatography (HPLC) assays, and in vivo drug release patterns. The electrospun nanofibers had a size range of 283-725 nm in diameter, resembling the extracellular matrix of natural tissue and demonstrated excellent flexibility and extensibility. Notably, the drug-eluting nanofibers exhibited an extended release of high levels of acyclovir and ketorolac over a 21-day period. Thus, biodegradable drug-eluting membranes with a prolonged drug release could be a potential therapeutic approach for treating herpes infections.

Diagnostic Methods and Management Strategies of Herpes Simplex and Herpes Zoster Infections

Herpesviruses are medium-sized double-stranded DNA viruses. Of more than 80 herpesviruses identified, only 9 human herpesviruses have been found to cause infection in humans. These include herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), human cyto-megalovirus (HCMV), Epstein-Barr virus (EBV), and human herpesvirus (HHV-6A, HHV-6B, HHV-7, HHV-8). HSV-1, HSV-2, and VZV can be problematic given their characteristic neurotropism which is the ability to invade via fusion of its plasma membrane and reside within neural tissue. HSV and VZV primarily infect mucocutaneous surfaces and remain latent in the dorsal root ganglia for a host's entire life. Reactivation causes either asymptomatic shedding of virus or clinical manifestation of vesicular lesions. The clinical presentation is influenced by the portal of entry, the immune status of the host, and whether the infection is primary or recurrent. Affecting 60% to 95% of adults, herpesvirus-associated infections include gingivostomatitis, orofacial and genital herpes,and primary varicella and herpes zoster. Symptomatology, treatment, and potential complications vary based on primary and recurrent infections as well as the patient's immune status.

Korean sexually transmitted infection guidelines 2023 revision, guideline update of viral infections: Genital herpes and anogenital warts

The Korean Association of Urogenital Tract Infection and Inflammation and the Korea Disease Control and Prevention Agency regularly update, revise, and develop new content for the Korean sexually transmitted infection (STI) guidelines. These professional bodies respond to changing epidemiological trends and evolving scientific evidence, and consider advances in laboratory diagnostics and research. The principal recommendations of the 2023 Korean STI guidelines in terms of viral infection follow: 1) If genital herpes recurs more than 4-6 times annually, suppressive therapy with acyclovir 400 mg orally 2 times/day or famciclovir 250 mg orally 2 times/day or valacyclovir 500 mg orally once a day (for patients with <10 episodes/year) or valacyclovir 1 g orally once daily (for patients with ≥10 episodes/year) is recommended to prevent recurrence; 2) molecular human papillomavirus (HPV) testing is not recommended as a routine test for STI status, nor for determination of HPV vaccination status; and 3) patients should inform their current sexual partners about anogenital warts because the types of HPV that cause such warts can be passed to partners. These guidelines will be updated every 5 years and will be revised when new knowledge on STIs becomes available and there is a reasonable need to improve the guidelines. Physicians and other healthcare providers can use the guidelines to assist in the prevention and treatment of STIs.

A Narrative Review of Alternative Symptomatic Treatments for Herpes Simplex Virus

Herpes simplex virus-1 (HSV-1) and -2 (HSV-2) are large, spherically shaped, double-stranded DNA viruses that coevolved with Homo sapiens for over 300,000 years, having developed numerous immunoevasive mechanisms to survive the lifetime of their human host. Although in the continued absence of an acceptable prophylactic and therapeutic vaccine, approved pharmacologics (e.g., nucleoside analogs) hold benefit against viral outbreaks, while resistance and toxicity limit their universal application. Against these shortcomings, there is a long history of proven and unproven home remedies. With the breadth of purported alternative therapies, patients are exposed to risk of harm without proper information. Here, we examined the shortcomings of the current gold standard HSV therapy, acyclovir, and described several natural products that demonstrated promise in controlling HSV infection, including lemon balm, lysine, propolis, vitamin E, and zinc, while arginine, cannabis, and many other recreational drugs are detrimental. Based on this literature, we offered recommendations regarding the use of such natural products and their further investigation.

Linear trends over 20 years in sexually transmitted infections among patients attending a tertiary care centre in north Kerala, India

BACKGROUND

Worldwide, a declining trend is observed in sexually transmitted infections of bacterial origin which is reflected as a rise in the proportion of viral sexually transmitted infections.

AIMS

To find out the clinical referral patterns of sexually transmitted infections among patients who attended the sexually transmitted infection clinic attached to Dermatology and Venereology Department of Government Medical College, Kozhikode from 1.1.1998 to 31.12.2017 and to study the linear trends in the pattern of sexually transmitted infections over 20 years.

METHODS

After clearance from the institutional ethics committee, a retrospective study was conducted among patients who attended the sexually transmitted infection clinic of Government Medical College, Kozhikode from 1.1.1998 to 31.12.2017 and were diagnosed to have sexually transmitted infections.

RESULTS

During the 20 year study period 5227 patients, attended the sexually transmitted infection clinic of our institution. Diagnosis of sexually transmitted infection was made in 2470 (47.3%) cases. Predominant sexually transmitted infections were herpes genitalis (964, 39%), condyloma acuminata (921, 37.9%) and syphilis (418, 17.2%). Viral sexually transmitted infections (1885, 76.3%) outnumbered bacterial sexually transmitted infections (575, 23.3%). A declining trend was noted for both bacterial and viral sexually transmitted infections over the 20 year period, which was more marked for the former. But the latter years of the study documented a rising trend in total sexually transmitted infections including bacterial sexually transmitted infections.

LIMITATIONS

The study does not reflect the status of sexually transmitted infections in the general population since it was conducted in a tertiary referral center.

CONCLUSION

The disturbing ascending trend recorded in sexually transmitted infections including syphilis during the final years of the 20-year period needs to be watched closely, to plan future strategies.

Host Cell Neddylation Facilitates Alphaherpesvirus Entry in a Virus-Specific and Cell-Dependent Manner

Herpes simplex virus 1 (HSV-1) commandeers the host cell proteasome at several steps of its replication cycle, including entry. Here we demonstrate that HSV-2, pseudorabies virus (PRV), and bovine herpesvirus 1 (BoHV-1) entry are blocked by bortezomib, a proteasome inhibitor that is an FDA-approved cancer drug. Proteasome-dependent entry of HSV-1 is thought to be ubiquitin-independent. To interrogate further the proteasomal mechanism of entry, we determined the involvement of the ubiquitin-like molecule NEDD8 and the neddylation cascade in alphaherpesvirus entry and infection. MLN4924 is a small-molecule inhibitor of neddylation that binds directly to the NEDD8-activating enzyme. Cell treatment with MLN4924 inhibited plaque formation and infectivity by HSV-1, PRV, and BoHV-1 at noncytotoxic concentrations. Thus, the neddylation pathway is broadly important for alphaherpesvirus infection. However, the neddylation inhibitor had little effect on entry of the veterinary viruses but had a significant inhibitory effect on entry of HSV-1 and HSV-2 into seven different cell types. Washout experiments indicated that MLN4924's effect on viral entry was reversible. A time-of-addition assay suggested that the drug was acting on an early step in the entry process. Small interfering RNA (siRNA) knockdown of NEDD8 significantly inhibited HSV entry. In probing the neddylation-dependent step in entry, we found that MLN4924 dramatically blocked endocytic uptake of HSV from the plasma membrane by >90%. In contrast, the rate of HSV entry into cells that support direct fusion of HSV with the cell surface was unaffected by MLN4924. Interestingly, proteasome activity was less important for the endocytic internalization of HSV from the cell surface. The results suggest that the NEDD8 cascade is critical for the internalization step of HSV entry. IMPORTANCE Alphaherpesviruses are ubiquitous pathogens of humans and veterinary species that cause lifelong latent infections and significant morbidity and mortality. Host cell neddylation is important for cell homeostasis and for the infection of many viruses, including HSV-1, HSV-2, PRV, and BoHV-1. Inhibition of neddylation by a pharmacologic inhibitor or siRNA blocked HSV infection at the entry step. Specifically, the NEDD8 pathway was critically important for HSV-1 internalization from the cell surface by an endocytosis mechanism. The results expand our limited understanding of cellular processes that mediate HSV internalization. To our knowledge, this is the first demonstration of a function for the neddylation cascade in virus entry.

Detection of herpes simplex virus 2: a SYBR-Green-based real-time PCR assay

The prevalence of Herpes simplex virus 2 (HSV2) is increasing at an alarming rate in the world. Most of the HSV2 cases are not diagnosed properly, although a range of molecular and serological diagnoses exist. Herein, we have reported a very rapid detection method specific for HSV2 using real-time PCR. The primers specific for HSV2 were designed using the Primer-BLAST tool and 120 base pairs of the polymerase gene were amplified using real-time PCR with SYBR Green dye. The designed primer pair was found highly efficient in detecting only HSV2 DNA, but not HSV1. The threshold cycle (Ct) value for HSV2 reactions by designed primers was found to be an average of 22.55 for a standard copy number of viral DNA that may denote the efficiency of the primers. The melting temperature (Tm) of the amplicon using designed primers (82.6 ⁰C) was also higher than that using reference primers (about 78 ⁰C), indicating the high GC content of the amplified template. The designed primer pair will help clinicians to detect the HSV2 DNA specifically and diagnose the associated disease rapidly.

CD8+ T cells in the central nervous system of mice with herpes simplex infection are highly activated and express high levels of CCR5 and CXCR3

Herpes simplex virus type 2 (HSV-2) is a neurotropic virus that can cause meningitis, an inflammation of the meninges in the central nervous system. T cells are key players in viral clearance, and these cells migrate from peripheral blood into the central nervous system upon infection. Several factors contribute to T cell migration, including the expression of chemokines in the inflamed tissue that attract T cells through their expression of chemokine receptors. Here we investigated CD8⁺ T cell profile in the spinal cord in a mouse model of herpes simplex virus type 2 neuroinflammation. Mice were infected with HSV-2 and sacrificed when showing signs of neuroinflammation. Cells and/or tissue from spinal cord, spleen, and blood were analyzed for expression of activation markers, chemokine receptors, and chemokines. High numbers of CD8⁺ T cells were present in the spinal cord following genital HSV-2-infection. CD8⁺ T cells were highly activated and HSV-2 glycoprotein B -specific effector cells, some of which showed signs of recent degranulation. They also expressed high levels of many chemokine receptors, in particular CCR2, CCR4, CCR5, and CXCR3. Investigating corresponding receptor ligands in spinal cord tissue revealed markedly increased expression of the cognate ligands CCL2, CCL5, CCL8, CCL12, and CXCL10. This study shows that during herpesvirus neuroinflammation anti-viral CD8⁺ T cells accumulate in the CNS. CD8⁺ T cells in the CNS also express chemotactic receptors cognate to the chemotactic gradients in the spinal cord. This indicates that anti-viral CD8⁺ T cells may migrate to infected areas in the spinal cord during herpesvirus neuroinflammation in response to chemotactic gradients.

Sexually Transmitted Infections: Part I: Genital Bumps and Genital Ulcers

Sexually transmitted infections (STIs) affect young people in a disproportionate way, with more than half of the infections occurring in 15- to 25-year-olds, although as an age group they constitute only 25% of the sexually active population. Pediatricians should be familiar with the social, behavioral, and biological factors that predispose adolescents to STIs. Preventive visits for teens and pre-teens should incorporate education and counseling about sexuality, safe sexual behavior, and STIs. Pediatricians should be able to identify, diagnose, and manage STIs presenting as genital "bumps" and genital "ulcers." Pediatricians should also offer human immunodeficiency virus testing and expedited partner treatment to all adolescents who are diagnosed as having an STI.

Biologic interactions between HSV-2 and HIV-1 and possible implications for HSV vaccine development

Development of a safe and effective vaccine against herpes simplex virus type 2 (HSV-2) has the potential to limit the global burden of HSV-2 infection and disease, including genital ulcer disease and neonatal herpes, and is a global sexual and reproductive health priority. Another important potential benefit of an HSV-2 vaccine would be to decrease HIV infections, as HSV-2 increases the risk of HIV-1 acquisition several-fold. Acute and chronic HSV-2 infection creates ulcerations and draws dendritic cells and activated CD4+ T cells into genital mucosa. These cells are targets for HIV entry and replication. Prophylactic HSV-2 vaccines (to prevent infection) and therapeutic vaccines (to modify or treat existing infections) are currently under development. By preventing or modifying infection, an effective HSV-2 vaccine could limit HSV-associated genital mucosal inflammation and thus HIV risk. However, a vaccine might have competing effects on HIV risk depending on its mechanism of action and cell populations generated in the genital mucosa. In this article, we review biologic interactions between HSV-2 and HIV-1, consider HSV-2 vaccine development in the context of HIV risk, and discuss implications and research needs for future HSV vaccine development.

Early Steps in Herpes Simplex Virus Infection Blocked by a Proteasome Inhibitor

Viruses commandeer host cell 26S proteasome activity to promote viral entry, gene expression, replication, assembly, and egress. Proteasomal degradation activity is critical for herpes simplex virus (HSV) infection. The proteasome inhibitor bortezomib (also known as Velcade and PS-341) is a clinically effective antineoplastic drug that is FDA approved for treatment of hematologic malignancies such as multiple myeloma and mantle cell lymphoma. Low nanomolar concentrations of bortezomib inhibited infection by HSV-1, HSV-2, and acyclovir-resistant strains. Inhibition coincided with minimal cytotoxicity. Bortezomib did not affect attachment of HSV to cells or inactivate the virus directly. Bortezomib acted early in HSV infection by perturbing two distinct proteasome-dependent steps that occur within the initial hours of infection: the transport of incoming viral nucleocapsids to the nucleus and the virus-induced disruption of host nuclear domain 10 (ND10) structures. The combination of bortezomib with acyclovir demonstrated synergistic inhibitory effects on HSV infection. Thus, bortezomib is a novel potential therapeutic for HSV with a defined mechanism of action.IMPORTANCE Viruses usurp host cell functions to advance their replicative agenda. HSV relies on cellular proteasome activity for successful infection. Proteasome inhibitors, such as MG132, block HSV infection at multiple stages of the infectious cycle. Targeting host cell processes for antiviral intervention is an unconventional approach that might limit antiviral resistance. Here we demonstrated that the proteasome inhibitor bortezomib, which is a clinically effective cancer drug, has the in vitro features of a promising anti-HSV therapeutic. Bortezomib inhibited HSV infection during the first hours of infection at nanomolar concentrations that were minimally cytotoxic. The mechanism of bortezomib's inhibition of early HSV infection was to halt nucleocapsid transport to the nucleus and to stabilize the ND10 cellular defense complex. Bortezomib and acyclovir acted synergistically to inhibit HSV infection. Overall, we present evidence for the repurposing of bortezomib as a novel antiherpesviral agent and describe specific mechanisms of action.

Comparison of Acyclovir and Multistrain Lactobacillus brevis in Women with Recurrent Genital Herpes Infections: a Double-Blind, Randomized, Controlled Study

We performed a randomized double-blind controlled trial to compare the efficacy and safety of multistrain probiotic and acyclovir in women patients with recurrent genital herpes simplex virus type 2 (HSV-2) infections. Eighty-one patients enrolled in the study were being treated with multistrain Lactobacillus brevis one vaginal capsule every 12 h and oral acyclovir 400 mg twice daily for 6 months. Of 53 patients who completed both treatment courses, no important differences were identified between acyclovir and probiotic for the primary and secondary efficacy endpoint, resolution of episode (hazard ratio, 0.60; 95% CI, 0.3429 to 1.0663; P = 0.08), lesion healing time (hazard ratio, 0.57; 95% CI, 0.3034 to 1.0717, P = 0.08), viral shedding (hazard ratio, 0.54; 95% CI, 0.3027 to 0.9750, P = 0.04), and percentage of pain (hazard ratio, 0.48; 95% CI, 0.2708 to 0.8545, P = 0.01). The median time to first and second recurrence after treatment were 43 and 121 days in patients receiving acyclovir and 33 and 118 days in patients receiving probiotic (HR 2.61; 95% CI, 1.4427 to 4.7546, P = 0.001, and HR 0.62; 95% CI, 0.3500 to 1.1133, P = 0.1, respectively). No clinically important effects happened during the probiotic treatment but some of adverse events reported in patients taking acyclovir. Easy availability, low cost, and no side effect of L. brevis are valuable properties of probiotic therapy compared with acyclovir. Therefore, we concluded that multistrain L. brevis could play an important role in suppression of recurrent genital herpes simplex virus infection.

Blood-borne and sexually transmitted infections: a cross-sectional study in a Swiss prison

Background

Incarcerated people carry a high burden of infection, including blood-borne diseases (BBDs). It is also known that one million people contract a sexually transmitted infection (STI) every day worldwide, which represents a global public health challenge. However, data regarding the prevalence of STIs and the risk factors among incarcerated populations are lacking. The objective of this study was to determine the prevalence and associated factors of BBDs and STIs among detainees in the largest pre-trial prison in Switzerland.

Methods

In a cross-sectional study conducted at the Champ-Dollon pre-trial prison, 273 male detainees answered a standardized questionnaire and were screened for syphilis, herpes simplex virus 2 (HSV-2), HIV, and hepatitis C (HCV). Prevalence rates and associations of BBDs and STIs with risk factors were computed.

Results

Most participants (90.9%) were migrants from outside Western Europe, and 5.9% were injecting drug users. HCV was diagnosed among 6.2% of participants (antibody prevalence). The prevalence of HCV was higher among injecting drug users (81.2%) than non-injectors (1.6%). The prevalence of HIV, syphilis, and HSV-2 was 0.4%, 1.1%, and 22.4%, respectively. HCV was associated with a history of injecting drug use and HSV-2 with a lower education level and being older than 26 years.

Conclusions

This study showed the infection prevalence of 2–9 times higher among detainees than in the Swiss community. It also illustrated that these infections are associated with sociodemographic and risk factors. Therefore, the prison environment offers an opportunity to strengthen infectious disease control programs targeting specific subgroups of at-risk people. Such programs would benefit both the prison population and broader society.

CRISPR/Cas9 and Genome Editing for Viral Disease-Is Resistance Futile?

Chronic viral infections remain a major public health issue affecting millions of people worldwide. Highly active antiviral treatments have significantly improved prognosis and infection-related morbidity and mortality but have failed to eliminate persistent viral forms. Therefore, new strategies to either eradicate or control these viral reservoirs are paramount to allow patients to stop antiretroviral therapy and realize a cure. Viral genome disruption based on gene editing by programmable endonucleases is one promising curative gene therapy approach. Recent findings on RNA-guided human immunodeficiency virus 1 (HIV-1) genome cleavage by Cas9 and other gene-editing enzymes in latently infected cells have shown high levels of site-specific genome disruption and potent inhibition of virus replication. However, HIV-1 can readily develop resistance to genome editing at a single antiviral target site. Current data suggest that cellular repair associated with DNA double-strand breaks can accelerate the emergence of resistance. On the other hand, a combination antiviral target strategy can exploit the same repair mechanism to functionally cure HIV-1 infection in vitro while avoiding the development of resistance. This perspective summarizes recent findings on the biology of resistance to genome editing and discusses the significance of viral genetic diversity on the application of gene editing strategies toward cure.

Genital herpes stigma: Toward the Measurement and Validation of a highly prevalent yet hidden public health problem

Despite its highly prevalent and stigmatizing nature, genital herpes has received little attention from stigma researchers relative to other sexually transmitted infections. This limitation is of great relevance to researchers and practitioners in both clinical and healthcare settings, given that stigma can cause psychological distress and hinder disclosure to sexual partners, hence contributing to the spread of genital herpes. The present research developed and examined the psychometric properties of a quantitative measure of genital herpes stigma. Two hundred individuals diagnosed with genital herpes recruited through online genital herpes support groups completed a survey containing 37 items adapted from the HIV Stigma Scale, questions about demographic and herpes-related characteristics, and measures of relevant psychosocial variables. A confirmatory factor analysis yielded an 18-item scale with four factors: personalized stigma, disclosure concerns, negative self-image, and concern with public attitudes. All subscales demonstrated good internal consistency, with Cronbach alphas ranging from 0.74 to 0.87. Construct validity was supported by correlations with relevant psychosocial variables, including negative affect, rumination, and perceived social support. As a psychometrically sound assessment tool, the Genital Herpes Stigma Scale can be used in both clinical and research settings to facilitate future efforts to alleviate the negative psychological consequences of this incurable viral infection.

Herpes simplex virus: 'to disclose or not to disclose.' An exploration of the multi-disciplinary team's role in advising patients about disclosure when diagnosed with genital herpes simplex virus

The first UK prosecution for genital herpes simplex virus (HSV) transmission in 2011 attracted strong criticism from medical experts. To address the dearth of research on the topic, this study aimed to explore the nature of advice given to patients by the multidisciplinary team (MDT) in the West of Scotland on HSV disclosure to partners. Ten semi-structured interviews with members of the MDT were conducted and the interviews were analysed using Burnard's Thematic Content Analysis. Four themes emerged which explored practitioners' knowledge of HSV and their feelings regarding the emotional aspects of the diagnosis on clients including the challenges of discussing disclosure. Within this framework, participants' attitudes to the legal prosecution were also surveyed. This study revealed that participants had good knowledge about HSV. Furthermore, participants believed disclosure to be the patient's choice and had not altered their practice to advise disclosure to all partners in accordance with local protocol. However, there was a general consensus that disclosure was not required due to the prevalence of HSV and prevalence was used to dissipate emotional reactions to HSV diagnosis.

Genotypic Characterization of Herpes Simplex Virus Type 1 Isolates in Immunocompromised Patients in Rio de Janeiro, Brazil

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen that causes a variety of diseases, including an increased risk of developing more severe disease in HIV-infected individuals. In Brazil, there is no information about the molecular epidemiology of HSV-1 infection, especially in HIV-infected individuals. The aim of this study was to perform the genotypic characterization of HSV-1 among HIV-infected patients. A total of 214 serum samples from HIV-positive patients without HSV infection symptoms were enrolled in one of two reference hospitals for HIV infection managing in Rio de Janeiro. The gG and gI genes were analyzed by restriction fragment length polymorphism (RFLP) and full nucleotide sequencing of the US8 (1601 bp), UL44 (1996 bp), and UL23 (1244 bp) regions was performed. A total of 38.3% (82/214) and 32.7% (70/214) of the serum samples tested positive for gG and gI genes, respectively. RFLP analysis classified the HSV-1 as belonging to genotype A. Phylogenetic analysis of the Brazilian samples for the US8, UL44, and UL23 regions demonstrated that the nucleotide identity between Brazilian samples was higher than 97% for all genes. No acyclovir mutation was detected in the patients. The shedding of HSV in the serum samples from HIV-positive patients who were asymptomatic for HSV infection was detected in this work. This is the first report of molecular characterization of HSV-1 in Brazilian samples since there is no previous data available in the literature concerning the genotypic classification and stable distribution of Brazilian strains of HSV-1 in Rio de Janeiro, Brazil.

Patient-Specific Neutralizing Antibody Responses to Herpes Simplex Virus Are Attributed to Epitopes on gD, gB, or Both and Can Be Type Specific

Herpes simplex virus 1 (HSV-1) and HSV-2 infect many humans and establish a latent infection in sensory ganglia. Although some infected people suffer periodic recurrences, others do not. Infected people mount both cell-mediated and humoral responses, including the production of virus-neutralizing antibodies (Abs) directed at viral entry glycoproteins. Previously, we examined IgGs from 10 HSV-seropositive individuals; all neutralized virus and were directed primarily against gD or gD+gB. Here, we expand our studies and examine 32 additional sera from HSV-infected individuals, 23 of whom had no recurrent disease. Using an Octet RED96 system, we screened all 32 serum samples directly for both glycoprotein binding and competition with known neutralizing anti-gD and -gB monoclonal Abs (MAbs). On average, the recurrent cohort exhibited higher binding to gD and gB and had higher neutralization titers. There were similar trends in the blocking of MAbs to critical gD and gB epitopes. When we depleted six sera of Abs to specific glycoproteins, we found different types of responses, but always directed primarily at gD and/or gB. Interestingly, in one dual-infected person, the neutralizing response to HSV-2 was due to gD2 and gB2, whereas HSV-1 neutralization was due to gD1 and gB1. In another case, virus neutralization was HSV-1 specific, with the Ab response directed entirely at gB1, despite this serum blocking type-common anti-gD and -gB neutralizing MAbs. These data are pertinent in the design of future HSV vaccines since they demonstrate the importance of both serotypes of gD and gB as immunogens.

IMPORTANCE

We previously showed that people infected with HSV produce neutralizing Abs directed against gD or a combination of gD+gB (and in one case, gD+gB+gC, which was HSV-1 specific). In this more extensive study, we again found that gD or gD+gB can account for the virus neutralizing response and critical epitopes of one or both of these proteins are represented in sera of naturally infected humans. However, we also found that some individuals produced a strong response against gB alone. In addition, we identified type-specific contributions to HSV neutralization from both gD and gB. Contributions from the other entry glycoproteins, gC and gH/gL, were minimal and limited to HSV-1 neutralization. Knowing the variations in how humans see and mount a response to HSV will be important to vaccine development.

Estimating the cost-effectiveness of pre-exposure prophylaxis to reduce HIV-1 and HSV-2 incidence in HIV-serodiscordant couples in South Africa

OBJECTIVE

To estimate the cost-effectiveness of daily oral tenofovir-based PrEP, with a protective effect against HSV-2 as well as HIV-1, among HIV-1 serodiscordant couples in South Africa.

METHODS

We incorporated HSV-2 acquisition, transmission, and interaction with HIV-1 into a microsimulation model of heterosexual HIV-1 serodiscordant couples in South Africa, with use of PrEP for the HIV-1 uninfected partner prior to ART initiation for the HIV-1 1infected partner, and for one year thereafter.

RESULTS

We estimate the cost per disability-adjusted life-year (DALY) averted for two scenarios, one in which PrEP has no effect on reducing HSV-2 acquisition, and one in which there is a 33% reduction. After a twenty-year intervention, the cost per DALY averted is estimated to be $10,383 and $9,757, respectively--a 6% reduction, given the additional benefit of reduced HSV-2 acquisition. If all couples are discordant for both HIV-1 and HSV-2, the cost per DALY averted falls to $1,445, which shows that the impact is limited by HSV-2 concordance in couples.

CONCLUSION

After a 20-year PrEP intervention, the cost per DALY averted with a reduction in HSV-2 is estimated to be modestly lower than without any effect, providing an increase of health benefits in addition to HIV-1 prevention at no extra cost. The small degree of the effect is in part due to a high prevalence of HSV-2 infection in HIV-1 serodiscordant couples in South Africa.

Herpes simplex virus type 2 among mobile pastoralists in northwestern Namibia

BACKGROUND

Although herpes simplex virus type 2 (HSV-2) epidemiology has been described for many western and/or urban populations, disease burden has not been characterized for remote, non-western, under treated populations, where patterns of risk and vulnerability may be very different.

AIMS

To understand demographic, behavioural and geographic influences on risk for HSV-2 in a population of mobile, rural pastoralists in northwestern Namibia.

SUBJECTS AND METHODS

The authors conducted a cross-sectional survey of reproductively aged adults (n = 445) across 28 villages in Kaokoveld, Namibia. All participants completed a questionnaire of demographic data, ecological interactions and sexual behaviour, and a rapid test specific for HSV-2.

RESULTS

HSV-2 status was significantly associated with being female (OR = 3.1, 95% CI = 2.00, 4.71), increasing age (men: OR = 7.5, 95% CI = 2.67, 20.85; women: OR = 6.2, 95% CI = 2.48, 15.50) and with higher wealth among men (OR = 5.1, 95% CI = 1.98, 13.09).

CONCLUSIONS

Higher risk among women can be explained, in part, by local hygiene practices and a preference for "dry" sex. There was considerable variation in prevalence by region, which appears to be linked to geographic remoteness. Culturally contextualized epidemiologic studies of remote, vulnerable populations can provide essential information for limiting the introduction and spread of new infections.

Comparative performance of the Uni-Gold™ HSV-2 Rapid: a point-of-care HSV-2 diagnostic test in unselected sera from a reference laboratory

BACKGROUND

HSV-2 diagnosis is typically by viral culture, viral DNA amplification of lesion material or by serology in cases of subclinical presentation. These methods can be time consuming and expensive. The Uni-Gold™ HSV-2 Rapid is a fast, point-of-care diagnostic test that can be performed outside a full service laboratory.

OBJECTIVE

To evaluate the ability of the Uni-Gold™ HSV-2 Rapid to correctly diagnose the presence or absence of anti-HSV-2 antibodies in patient serum samples in comparison to the University of Washington HSV Western blot (UWWB).

STUDY DESIGN

Sera from 100 adult patients in the USA were tested for HSV-2 specific antibodies by Uni-Gold™ HSV-2 Rapid and results were compared to those of the UWWB to determine the test's sensitivity and specificity.

RESULTS

Of 18 patients seropositive for HSV-2 by UWWB, 17 were correctly identified as such by the Uni-Gold™ HSV-2 Rapid. Of 76 patients who were seronegative for HSV-2 by UWWB, 75 were correctly identified by the rapid test. Six sera had indeterminate results by UWWB. Sensitivity for the Uni-Gold™ HSV-2 Rapid was 94% and specificity was 99%.

CONCLUSION

The Uni-Gold™ HSV-2 Rapid had high sensitivity and specificity in a small sample of unselected, adults seeking care in the Seattle, USA area. An accurate, near-person test allows immediate counseling directed toward symptom recognition, treatment, and practices that can limit the risk of HSV-2 transmission.

Repertoire of epitopes recognized by serum IgG from humans vaccinated with herpes simplex virus 2 glycoprotein D

The results of a clinical trial of a subunit vaccine against genital herpes were recently reported (R. B. Belshe, P. A. Leone, D. I. Bernstein, A. Wald, M. J. Levin, J. T. Stapleton, I. Gorfinkel, R. L. Morrow, M. G. Ewell, A. Stokes-Riner, G. Dubin, T. C. Heineman, J. M. Schulte, C. D. Deal, N. Engl. J. Med. 366: 34-43, 2012, doi:10.1056/NEJMoa1103151). The vaccine consisted of a soluble form of herpes simplex virus 2 (HSV-2) glycoprotein D (gD2) with adjuvant. The goal of the current study was to examine the composition of the humoral response to gD2 within a selected subset of vaccinated individuals. Serum samples from 30 vaccine recipients were selected based upon relative enzyme-linked immunosorbent assay (ELISA) titers against gD2; 10 samples had high titers, 10 had medium titers, and the remaining 10 had low ELISA titers. We employed a novel, biosensor-based monoclonal antibody (MAb)-blocking assay to determine whether gD2 vaccination elicited IgG responses against epitopes overlapping those of well-characterized MAbs. Importantly, IgGs from the majority of gD2-immunized subjects competed for gD binding with four antigenically distinct virus-neutralizing MAbs (MC2, MC5, MC23, and DL11). Screening of patient IgGs against overlapping peptides spanning the gD2 ectodomain revealed that about half of the samples contained antibodies against linear epitopes within the N and C termini of gD2. We found that the virus-neutralizing abilities of the 10 most potent samples correlated with overall gD-binding activity and to an even greater extent with the combined content of IgGs against the epitopes of MAbs MC2, MC5, MC23, and DL11. This suggests that optimal virus-neutralizing activity is achieved by strong and balanced responses to the four major discontinuous neutralizing epitopes of gD2. Importance: Several herpes simplex virus 2 (HSV-2) subunit vaccine studies have been conducted in human subjects using a recombinant form of HSV-2 glycoprotein D (gD2). Although several distinct, well-characterized virus-neutralizing epitopes on gD2 are targeted by murine monoclonal antibodies, it is not known whether the same epitopes are targeted by the humoral response to gD2 in humans. We have developed a novel, biosensor-based competition assay to directly address this important question. Using this approach, we identified epitopes that elicit strong humoral responses in humans, as well as other epitopes that elicit much weaker responses. These data provide new insight into the human response to known neutralizing gD2 epitopes and reveal characteristics of this response that may guide future vaccine development.

Stability of glycoprotein gene sequences of herpes simplex virus type 2 from primary to recurrent human infection, and diversity of the sequences among patients attending an STD clinic

Background

Herpes simplex virus type 2 (HSV-2) is sexually transmitted, leading to blisters and ulcers in the genito-anal region. After primary infection the virus is present in a latent state in neurons in sensory ganglia. Reactivation and production of new viral particles can cause asymptomatic viral shedding or new lesions. Establishment of latency, maintenance and reactivation involve silencing of genes, continuous suppression of gene activities and finally gene activation and synthesis of viral DNA. The purpose of the present work was to study the genetic stability of the virus during these events.

Methods

HSV-2 was collected from 5 patients with true primary and recurrent infections, and the genes encoding glycoproteins B,G,E and I were sequenced.

Results

No nucleotide substitution was observed in any patient, indicating genetic stability. However, since the total number of nucleotides in these genes is only a small part of the total genome, we cannot rule out variation in other regions.

Conclusions

Although infections of cell cultures and animal models are useful for studies of herpes simplex virus, it is important to know how the virus behaves in the natural host. We observed that several glycoprotein gene sequences are stable from primary to recurrent infection. However, the virus isolates from the different patients were genetically different.

In vitro Inactivation of Latent HSV by Targeted Mutagenesis Using an HSV-specific Homing Endonuclease

Following acute infection, herpes simplex virus (HSV) establishes latency in sensory neurons, from which it can reactivate and cause recurrent disease. Available antiviral therapies do not affect latent viral genomes; therefore, they do not prevent reactivation following therapy cessation. One possible curative approach involves the introduction of DNA double strand breaks in latent HSV genomes by rare-cutting endonucleases, leading to mutagenesis of essential viral genes. We tested this approach in an in vitro HSV latency model using the engineered homing endonuclease (HE) HSV1m5, which recognizes a sequence in the HSV-1 gene UL19, encoding the virion protein VP5. Coexpression of the 3'-exonuclease Trex2 with HEs increased HE-mediated mutagenesis frequencies up to sixfold. Following HSV1m5/Trex2 delivery with adeno-associated viral (AAV) vectors, the target site was mutated in latent HSV genomes with no detectable cell toxicity. Importantly, HSV production by latently infected cells after reactivation was decreased after HSV1m5/Trex2 exposure. Exposure to histone deacetylase inhibitors prior to HSV1m5/Trex2 treatment increased mutagenesis frequencies of latent HSV genomes another two- to fivefold, suggesting that chromatin modification may be a useful adjunct to gene-targeting approaches. These results support the continuing development of HEs and other nucleases (ZFNs, TALENs, CRISPRs) for cure of chronic viral infections.Molecular Therapy-Nucleic Acids (2014) 3, e1; doi:10.1038/mtna.2013.75; published online 4 February 2014.

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.

The immunologic basis for severe neonatal herpes disease and potential strategies for therapeutic intervention

Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) infect a large proportion of the world's population. Infection is life-long and can cause periodic mucocutaneous symptoms, but it only rarely causes life-threatening disease among immunocompetent children and adults. However, when HSV infection occurs during the neonatal period, viral replication is poorly controlled and a large proportion of infants die or develop disability even with optimal antiviral therapy. Increasingly, specific differences are being elucidated between the immune system of newborns and those of older children and adults, which predispose to severe infections and reflect the transition from fetal to postnatal life. Studies in healthy individuals of different ages, individuals with primary or acquired immunodeficiencies, and animal models have contributed to our understanding of the mechanisms that control HSV infection and how these may be impaired during the neonatal period. This paper outlines our current understanding of innate and adaptive immunity to HSV infection, immunologic differences in early infancy that may account for the manifestations of neonatal HSV infection, and the potential of interventions to augment neonatal immune protection against HSV disease.

The efficacy of HSV-2 vaccines based on gD and gB is enhanced by the addition of ICP27

DNA vaccines expressing HSV-2 gD, gB, ICP27, VP22 and VP13/14 were shown to be immunogenic in mice; gD and gB elicited neutralising antibody, and all five antigens induced T cell responses measured by IFNγ ELISPOT. In murine HSV-2 challenge studies, gD and gB provided moderate to high levels of protection while ICP27 provided a lower level of protection depending on the model (intravaginal or intranasal) and the challenge dose. Combining vaccines expressing gB or gD with vaccines expressing ICP27 provided greater protection than any antigen alone. We conclude that the addition of ICP27 to enhance the anti-viral T cell response can improve the efficacy of gD- and gB-based vaccines.

Immunogenicity and efficacy of intramuscular replication-defective and subunit vaccines against herpes simplex virus type 2 in the mouse genital model

Herpes simplex virus type 2 (HSV-2) is a sexually transmitted virus that is highly prevalent worldwide, causing a range of symptoms that result in significant healthcare costs and human suffering. ACAM529 is a replication-defective vaccine candidate prepared by growing the previously described dl5-29 on a cell line appropriate for GMP manufacturing. This vaccine, when administered subcutaneously, was previously shown to protect mice from a lethal vaginal HSV-2 challenge and to afford better protection than adjuvanted glycoprotein D (gD) in guinea pigs. Here we show that ACAM529 given via the intramuscular route affords significantly greater immunogenicity and protection in comparison with subcutaneous administration in the mouse vaginal HSV-2 challenge model. Further, we describe a side-by-side comparison of intramuscular ACAM529 with a gD vaccine across a range of challenge virus doses. While differences in protection against death are not significant, ACAM529 protects significantly better against mucosal infection, reducing peak challenge virus shedding at the highest challenge dose by over 500-fold versus 5-fold for gD. Over 27% (11/40) of ACAM529-immunized animals were protected from viral shedding while 2.5% (1/40) were protected by the gD vaccine. Similarly, 35% (7/20) of mice vaccinated with ACAM529 were protected from infection of their dorsal root ganglia while none of the gD-vaccinated mice were protected. These results indicate that measuring infection of the vaginal mucosa and of dorsal root ganglia over a range of challenge doses is more sensitive than evaluating survival at a single challenge dose as a means of directly comparing vaccine efficacy in the mouse vaginal challenge model. The data also support further investigation of ACAM529 for prophylaxis in human subjects.

Geldanamycin, a ligand of heat shock protein 90, inhibits herpes simplex virus type 2 replication both in vitro and in vivo

Previously, we discovered geldanamycin, a ligand of heat shock protein 90, effectively inhibited herpes simplex virus type 1 replication in vitro and in vivo (mouse encephalitis model). In this study, we demonstrate that geldanamycin has very strong activities against herpes simplex virus type 2 in vitro and in vivo (mouse vagina model). In mouse vagina model, administration of geldanamycin suspension to vagina after virus infection protected the infected mice from death and increased the average survival days in a dose-dependent manner. Geldanamycin also significantly reduced virus shedding from mouse vagina. All geldanamycin-treated groups were statistically significant when compared with the infected control group. The high-dose group of geldanamycin (5.72 mg kg⁻¹) was better than acyclovir group (2.86 mg kg⁻¹). All geldanamycin vaginal administration mock-infected groups did not show significant body weight loss. Although geldanamycin has strong antiviral activities against various DNA and RNA viruses, geldanamycin is not suitable for systemic administration because of its high toxicity. We consider that geldanamycin is a candidate of topical usage for the treatment of herpes simplex virus type infections.

Severe Primary HSV-2 in a Perinatal HIV-Infected Woman with Advanced Immunosuppression

Herpes simplex virus type 2 (HSV-2) is most commonly associated with mucocutaneous manifestations; however, coinfections with HIV may be associated with atypical and more severe presentations of clinical disease. We present a case of a young woman with advanced perinatally acquired AIDS presenting with severe purulent pharyngitis, fevers, and toxic appearance with a subsequent diagnosis of disseminated primary HSV-2 infection in multiple noncontiguous mucocutaneous sites. This case highlights an unusual presentation of the protean nature of primary HSV infection and the potential severity of illness in patients with advanced immunosuppression.

Targeted DNA mutagenesis for the cure of chronic viral infections

Human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV), and herpes simplex virus (HSV) have been incurable to date because effective antiviral therapies target only replicating viruses and do not eradicate latently integrated or nonreplicating episomal viral genomes. Endonucleases that can target and cleave critical regions within latent viral genomes are currently in development. These enzymes are being engineered with high specificity such that off-target binding of cellular DNA will be absent or minimal. Imprecise nonhomologous-end-joining (NHEJ) DNA repair following repeated cleavage at the same critical site may permanently disrupt translation of essential viral proteins. We discuss the benefits and drawbacks of three types of DNA cleavage enzymes (zinc finger endonucleases, transcription activator-like [TAL] effector nucleases [TALENs], and homing endonucleases [also called meganucleases]), the development of delivery vectors for these enzymes, and potential obstacles for successful treatment of chronic viral infections. We then review issues regarding persistence of HIV-1, HBV, and HSV that are relevant to eradication with genome-altering approaches.

The molecular basis of herpes simplex virus latency

Herpes simplex virus type 1 is a neurotropic herpesvirus that establishes latency within sensory neurones. Following primary infection, the virus replicates productively within mucosal epithelial cells and enters sensory neurones via nerve termini. The virus is then transported to neuronal cell bodies where latency can be established. Periodically, the virus can reactivate to resume its normal lytic cycle gene expression programme and result in the generation of new virus progeny that are transported axonally back to the periphery. The ability to establish lifelong latency within the host and to periodically reactivate to facilitate dissemination is central to the survival strategy of this virus. Although incompletely understood, this review will focus on the mechanisms involved in the regulation of latency that centre on the functions of the virus-encoded latency-associated transcripts (LATs), epigenetic regulation of the latent virus genome and the molecular events that precipitate reactivation.

This review considers current knowledge and hypotheses relating to the mechanisms involved in the establishment, maintenance and reactivation herpes simplex virus latency.

The psychological impact of genital herpes stigma

This article reviews the psychological consequences of genital herpes infection through the lens of a recently proposed framework for conceptualizing concealable stigmas. We incorporate research on identity, stigma, and the connection between psychological and physical health to outline how negative stigma-related psychological consequences perpetuate distress associated with genital herpes. Our review of the research suggests a model linking negative affect and poor coping to frequent recurrences of genital herpes outbreaks. Frequent outbreaks, in turn, increase the salience of the stigma, reinforcing a stigmatized self-schema, thereby creating negative psychological consequences, continuing the cycle. We conclude by discussing the implications of this model for future research and mental health treatment.

Recurrent vaginal shedding of herpes simplex type 2 virus in the mouse and effects of antiviral therapy

A mouse model of recurrent herpes simplex type 2 (HSV-2) would improve our understanding of the immunobiology of recurrent disease and provide a useful model for evaluating antiviral treatments. We developed a model to evaluate recurrent vaginal HSV-2 shedding using high-dose acyclovir (ACV) therapy beginning at 3 days post infection (dpi). Treatment with 150mg/kg of ACV for 10 days increased survival to 80% following vaginal challenge with HSV-2 strain 186 and to 100% after challenge with strain MS. We then evaluated recurrent vaginal HSV-2 shedding in surviving mice. Although infectious virus was not detected in vaginal samples after 21dpi, viral DNA was detectable by PCR in 80% of mice (47/59) on at least 1 day, while no animal was positive for virus on every day. ACV therapy administered from day 21 to 31 significantly reduced recurrent virus shedding during this period from 7.3% (8/109 swabs) to 0.8% (1/126 swabs) (p=0.013). Lastly, ACV-rescued HSV-2-infected mice treated with cyclophosphamide at 35 and 38dpi rapidly succumbed, indicating that this model can be used to study immune control of the persistent infection. Thus, this model provides an inexpensive model for evaluating therapeutic strategies and immune control of persistent HSV.