Time Trends in First-Episode Genital Herpes Simplex Virus Infections in an Urban Sexually Transmitted Disease Clinic

A fur plucking model to study herpes simplex virus reactivation and recurrent disease

Herpes simplex viruses (HSV-1 and HSV-2) most commonly cause ulcerative epithelial lesions (cold sores and genital herpes). Importantly, HSV establishes life-long persistent (latent) infection in peripheral neurons. Reactivation from latency produces recurrent epithelial lesions, which constitute the greatest burden of HSV disease in people. The mechanisms that regulate latency and reactivation remain incompletely understood, in part due to limitations in the animal models available for studying HSV reactivation. We have developed a simple and tractable model to induce HSV-1 and HSV-2 reactivation from latency to cause recurrent skin disease. We infected C57BL/6 mice with HSV-1 (strains NS, F, SC16, 17syn+) or HSV-2 (strain 333) on flank skin depilated by manual plucking. After at least 35 days post-infection (dpi), we replucked the fur from the infected flank and observed recurrent lesions in the same dermatome as the primary infection. We detected HSV DNA in dermatome skin through 4 days post-replucking and observed viral antigen and reporter signal in skin lesions by histology, consistent with viral replication following reactivation. In addition to C57BL/6 mice, we were able to produce reactivation in Balb/c and SKH-1 mice. We found that shaving the ipsilateral flank or plucking the contralateral flank did not induce recurrent skin lesions, suggesting that fur plucking is a specific stimulus that induces HSV reactivation. Furthermore, we were able to induce multiple rounds of plucking-induced recurrent disease, providing a model to investigate the lifelong nature of HSV infection. This new model provides a tractable system for studying pathogenic mechanisms of and therapeutic interventions against HSV reactivation and recurrent disease.

IMPORTANCE

Herpes simplex viruses (HSV-1 and HSV-2) have infected over half of the US adult population to cause a lifelong, persistent infection; however, our understanding of the mechanisms that govern HSV reactivation and recurrent disease is incomplete. This is in part due to limitations in the animal models used to study recurrent disease, which are laborious and inefficient in mice. To address this technical gap, we developed a mouse model in which fur plucking after flank skin infection is sufficient to induce episodes of HSV reactivation and recurrent disease. Our work provides a model for the field to investigate the pathogenic mechanisms of HSV and immune responses during recurrent disease and provides an opportunity to investigate the neurobiology of HSV infection.

Comparison of the Accuracy of HSV1 and HSV2 Antibody Tests with PCR in the Diagnosis of Recurrent Genital Herpes

Objective

To assess the accuracy of HSV1and HSV2 antibody testing in identifying genital herpes infection.

Methods

A cohort of 299 patients previously diagnosed with recurrent genital herpes, confirmed via PCR, were tested using ELISA for HSV1 and HSV2 IgM and IgG antibodies. The study compared the accuracy of HSV1 and HSV2 antibody tests in diagnosing genital herpes.

Results

Among 299 patients, 14 tested positives for HSV1 DNA. Of these, 9 had HSV1 IgG antibodies, but none had HSV2 IgG antibody. Among 278 patients with HSV2 DNA, 149 had HSV1 IgG, 9 had HSV2 IgG, and 97 had both. Seven patients had both HSV1 and HSV2 DNA; 3 had HSV1 IgG, 1 had HSV2 IgG, and 3 had both. The accuracy of HSV1 IgG for HSV1 infection was 64.2%, and for HSV1 and HSV2 co-infection, 85.7%. The accuracy of HSV2 IgG for HSV2 infection was 38.1%, and for HSV1 and HSV2 co-infection, 57.1%. The combined antibody positivity accuracy was 34.9%.

Conclusion

Genital herpes is primarily caused by HSV2 (92.98%). A smaller percentage is HSV1 (4.67%) or co-infection (2.34%). Despite relatively low diagnostic accuracy (34.9-85.7%) for antibody detection, combined antibody testing is necessary. Herpes DNA testing is recommended for accurate diagnosis. Absence of antibodies does not rule out genital herpes and clinical assessment is essential.

Epidemiology of herpes simplex virus type 1 in Canada: systematic review, meta-analyses, and meta-regressions

Background

The objective of this study was to characterize herpes simplex virus type 1 (HSV-1) epidemiology in Canada.

Methods

HSV-1 publications as recent as December 6, 2021 were systematically reviewed, synthesized, and reported following PRISMA guidelines. Meta-analyses and meta-regressions were conducted.

Results

HSV-1 measures were extracted from 22 studies and included 32 overall seroprevalence measures (79 stratified), 2 overall proportions of HSV-1 detection in clinically diagnosed genital ulcer disease (2 stratified), and 8 overall proportions of HSV-1 detection in laboratory-confirmed genital herpes (27 stratified). Pooled mean seroprevalence was 19.1% [95% confidence interval (CI): 12.6-26.4%] among healthy children and 51.4% (95% CI: 47.3-55.5%) among healthy adults. Pooled mean seroprevalence among healthy general populations increased with age, with the lowest being 35.7% (95% CI: 29.1-42.6%) among individuals <20 years of age, and the highest being 70.0% (95% CI: 54.8-83.2) among individuals ≥40 years. Seroprevalence increased by 1.02-fold (95% CI: 1.01-1.04) per year. Pooled mean proportion of HSV-1 detection in genital ulcer disease was 30.8% (95% CI: 12.6-52.8%). Pooled mean proportion of HSV-1 detection in genital herpes was 37.4% (95% CI: 29.5-45.6%) and was highest in women and in young persons. Proportion of HSV-1 detection in genital herpes increased by 1.04-fold (95% CI: 1.00-1.08) per year.

Conclusions

HSV-1 epidemiology in Canada appears to be shifting toward less oral acquisition in childhood and more genital acquisition in adulthood, particularly among youth. Both HSV-1 seroprevalence and proportion of HSV-1 detection in genital herpes are increasing with time.

Antiviral activity of amide-appended α-hydroxytropolones against herpes simplex virus-1 and -2

α-Hydroxytropolones (αHTs) have potent antiviral activity against herpes simplex virus-1 and -2 (HSV-1 and HSV-2) in cell culture, including against acyclovir-resistant mutants, and as a result have the potential to be developed as antiviral drugs targeting these viruses. We recently described a convenient final-step amidation strategy to their synthesis, and this was used to generate 57 amide-substituted αHTs that were tested against hepatitis B virus. The following manuscript describes the evaluation of this library against HSV-1, as well as a subset against HSV-2. The structure-function analysis obtained from these studies demonstrates the importance of lipophilicity and rigidity to αHT-based anti-HSV potency, consistent with our prior work on smaller libraries. We used this information to synthesize and test a targeted library of 4 additional amide-appended αHTs. The most potent of this new series had a 50% effective concentration (EC₅₀) for viral inhibition of 72 nM, on par with the most potent αHT antivirals we have found to date. Given the ease of synthesis of amide-appended αHTs, this new class of antiviral compounds and the chemistry to make them should be highly valuable in future anti-HSV drug development.

Epidemiology of herpes simplex virus type 1 and genital herpes in Australia and New Zealand: systematic review, meta-analyses and meta-regressions

Herpes simplex virus type 1 (HSV-1) infection is a lifelong infection that is acquired primarily orally and during childhood. We aimed to characterise HSV-1 epidemiology in Australia and New Zealand. HSV-1-related data as recent as 6 December 2021 were systematically reviewed, synthesised and reported, following PRISMA guidelines. Pooled mean seroprevalence and proportions of HSV-1 detection in genital ulcer disease (GUD) and in genital herpes were calculated using random-effects meta-analyses. Meta-regressions were also conducted. HSV-1 measures were retrieved from 21 eligible publications. Extracted HSV-1 measures included 13 overall seroprevalence measures (27 stratified) in Australia, four overall proportions of HSV-1 detection in clinically diagnosed GUD (four stratified) in Australia, and ten overall proportions of HSV-1 detection in laboratory-confirmed genital herpes (26 stratified) in Australia and New Zealand. Pooled mean seroprevalence among healthy adults in Australia was 84.8% (95% confidence interval (CI) 74.3-93.1%). Pooled mean seroprevalence was 70.2% (95% CI 47.4-88.7%) among individuals <35 years of age and 86.9% (95% CI 79.3-93.0%) among individuals ≥35 years. Seroprevalence increased by 1.05-fold (95% CI 1.01-1.10) per year. Pooled mean proportion of HSV-1 detection in GUD was 8.2% (95% CI 0.4-22.9%). Pooled mean proportion of HSV-1 detection in genital herpes was 30.5% (95% CI 23.3-38.3%), and was highest in young individuals. Proportion of HSV-1 detection in genital herpes increased by 1.04-fold (95% CI 1.00-1.08) per year. Included studies showed heterogeneity, but 30% of the heterogeneity in seroprevalence and 42% of the heterogeneity in proportion of HSV-1 detection in genital herpes were explained in terms of epidemiological factors. HSV-1 seroprevalence is higher in Australia than in other Western countries. HSV-1 epidemiology in Australia and New Zealand appears to be transitioning towards less oral acquisition in childhood, but more genital acquisition among youth.

Epidemiology of herpes simplex virus type 2 in Europe: systematic review, meta-analyses, and meta-regressions

Background

Herpes simplex virus type 2 (HSV-2) infection is a globally prevalent, life-long, sexually transmitted infection. This study characterized HSV-2 seroprevalence in Europe for various at-risk populations and proportions of HSV-2 detection in genital ulcer disease (GUD) and in genital herpes. Data on neonatal herpes and HSV-2's contribution to HIV transmission were also reviewed.

Methods

Cochrane and PRISMA guidelines were followed to systematically review, synthesize, and report HSV-2 related findings. The search was conducted in PubMed and Embase databases up to February 20, 2022. Any publication reporting data on the outcome measures was included. Meta-analyses and meta-regressions were conducted.

Findings

211 relevant reports were identified, including 12 overall incidence measures, 294 overall (813 stratified by factors such as age and sex) seroprevalence measures, 13 overall (15 stratified by sex) proportions of HSV-2 detection in clinically diagnosed GUD, and 70 overall (183 stratified by factors such as age and sex) proportions of HSV-2 detection in laboratory-confirmed genital herpes. Pooled mean seroprevalence was 12.4% (95% CI: 11.5-13.3%) among general populations, 27.8% (95% CI: 17.5-39.4%) among men who have sex with men, 46.0% (95% CI: 40.1-51.8%) among people living with HIV and people in HIV discordant couples, and 63.2% (95% CI: 55.5-70.6%) among female sex workers. Most measures showed heterogeneity in HSV-2 seroprevalence. The pooled mean seroprevalence among general populations increased with age and was 0.65-fold (95% CI: 0.58-0.74) lower in men than women. Seroprevalence decreased by 1% per calendar year. Pooled mean proportions of HSV-2 detection in GUD and in genital herpes were 22.0% (95% CI: 15.3-29.6%) and 66.0% (95% CI: 62.9-69.1%), respectively. HSV-2 detection in genital herpes cases was 1.21-fold (95% CI: 1.10-1.32) higher in men compared to women and decreased by 1% per calendar year. Incidence of neonatal herpes indicated an increasing trend.

Interpretation

Although seroprevalence is declining, a significant proportion of Europe's population is infected with HSV-2. HSV-2 accounts for approximately one-fifth of GUD cases and two-thirds of genital herpes cases. Findings support the need to invest in HSV-2 vaccine development, and sexual and reproductive health services.

Funding

Qatar National Research Fund [NPRP 9-040-3-008] and pilot funding from the Biomedical Research Program at Weill Cornell Medicine in Qatar supported this study.

Diagnosis and Management of Genital Herpes: Key Questions and Review of the Evidence for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

Genital herpes, caused by herpes simplex virus (HSV) type 1 or type 2, is a prevalent sexually transmitted infection (STI). Given that HSV is an incurable infection, there are important concerns about appropriate use of diagnostic tools, management of infection, prevention of transmission to sexual partners, and appropriate counseling. In preparation for updating the Centers for Disease Control and Prevention (CDC) STI treatment guidelines, key questions for management of genital herpes infection were developed with a panel of experts. To answer these questions, a systematic literature review was performed, with tables of evidence including articles that would change guidance assembled. These data were used to inform recommendations in the 2021 CDC STI treatment guidelines.

Neonatal Herpes Simplex Virus Infection: Epidemiology and Outcomes in the Modern Era

BACKGROUND

Over the past several decades, there have been advances in diagnosis and treatment of neonatal herpes simplex virus (HSV) disease. There has been no recent comprehensive evaluation of the impact of these advances on the management and outcomes for neonates with HSV.

METHODS

Clinical data for initial presentation, treatment, and outcomes were abstracted from medical records of neonates with HSV treated at Seattle Children's Hospital between 1980 and 2016.

RESULTS

One hundred thirty infants with a diagnosis of neonatal HSV were identified. Between 1980 and 2016, high-dose acyclovir treatment for neonatal HSV infection increased from 0% to close to 95%, with subsequent decrease in overall HSV-related mortality from 20.9% to 5.6%. However, even among infants treated with high-dose acyclovir, mortality was 40.9% for infants with disseminated (DIS) disease, and only 55% of infants with central nervous system (CNS) disease were without obvious neurologic abnormalities at 24 months. Over the study period, the time between initial symptoms and diagnosis decreased. Skin recurrences were more common with HSV-2 than HSV-1 (80% vs 55%; P = .02) and in infants with lesions at initial diagnosis (76% vs 47%; P = .02).

CONCLUSION

Changes in the standard of care for management of neonatal HSV disease have led to improvements in timeliness of diagnosis and outcome but mortality in infants with DIS disease and neurologic morbidity in infants with CNS disease remain high. Future research should focus on prevention of perinatal infection and subsequent recurrences.

Herpes simplex virus type 1 in Europe: systematic review, meta-analyses and meta-regressions

Objective

To describe the epidemiology of herpes simplex virus type 1 (HSV-1) in Europe.

Methods

We systematically reviewed HSV-1 related publications, conducted various meta-analyses and meta-regressions, assessed pooled mean seroprevalence, and estimated pooled mean proportions of HSV-1 viral detection in clinically diagnosed genital ulcer disease (GUD) and in genital herpes.

Results

We extracted, from 142 relevant records, 179 overall (622 stratified) seroprevalence measures, 4 overall proportions of HSV-1 in GUD and 64 overall (162 stratified) proportions of HSV-1 in genital herpes. Pooled mean seroprevalence was 67.4% (95% CI 65.5% to 69.3%) with 32.5% (95% CI 29.4% to 35.7%) of children and 74.4% (95% CI 72.8% to 76.0%) of adults infected. Pooled seroprevalence increased steadily with age, being lowest in those aged <20 years (39.3%, 95% CI 35.9% to 42.7%) and highest in those aged >50 years (82.9%, 95% CI 78.8% to 86.6%). Pooled seroprevalence decreased yearly by 0.99-fold (95% CI 0.99 to 1.00). Pooled mean proportion of HSV-1 detection was 13.6% (95% CI 4.1% to 27.1%) in GUD, 34.1% (95% CI 31.7% to 36.5%) in genital herpes and 49.3% (95% CI 42.2% to 56.4%) in first episode genital herpes. Pooled proportion of HSV-1 detection in genital herpes increased yearly by 1.01-fold (95% CI 1.00 to 1.02), with higher detection in women (42.0%, 95% CI 37.4% to 46.7%) than men (24.1%, 95% CI 19.8% to 28.6%).

Conclusions

HSV-1 epidemiology is transitioning away from its historical pattern of oral acquisition in childhood. Every year, seroprevalence is declining by 1% and the proportion of HSV-1 in genital herpes is increasing by 1%. As many as two-thirds of children are reaching sexual debut unexposed, and at risk of HSV-1 genital acquisition in adulthood.

An HSV-2 nucleoside-modified mRNA genital herpes vaccine containing glycoproteins gC, gD, and gE protects mice against HSV-1 genital lesions and latent infection

HSV-1 causes 50% of first-time genital herpes infections in resource-rich countries and affects 190 million people worldwide. A prophylactic herpes vaccine is needed to protect against genital infections by both HSV-1 and HSV-2. Previously our laboratory developed a trivalent vaccine that targets glycoproteins C, D, and E present on the HSV-2 virion. We reported that this vaccine protects animals from genital disease and recurrent virus shedding following lethal HSV-2 challenge. Importantly the vaccine also generates cross-reactive antibodies that neutralize HSV-1, suggesting it may provide protection against HSV-1 infection. Here we compared the efficacy of this vaccine delivered as protein or nucleoside-modified mRNA immunogens against vaginal HSV-1 infection in mice. Both the protein and mRNA vaccines protected mice from HSV-1 disease; however, the mRNA vaccine provided better protection as measured by lower vaginal virus titers post-infection. In a second experiment, we compared protection provided by the mRNA vaccine against intravaginal challenge with HSV-1 or HSV-2. Vaccinated mice were totally protected against death, genital disease and infection of dorsal root ganglia caused by both viruses, but somewhat better protected against vaginal titers after HSV-2 infection. Overall, in the two experiments, the mRNA vaccine prevented death and genital disease in 54/54 (100%) mice infected with HSV-1 and 20/20 (100%) with HSV-2, and prevented HSV DNA from reaching the dorsal root ganglia, the site of virus latency, in 29/30 (97%) mice infected with HSV-1 and 10/10 (100%) with HSV-2. We consider the HSV-2 trivalent mRNA vaccine to be a promising candidate for clinical trials for prevention of both HSV-1 and HSV-2 genital herpes.

Vaccines to prevent genital herpes

Genital herpes increases the risk of acquiring and transmitting Human Immunodeficiency Virus (HIV), is a source of anxiety for many about transmitting infection to intimate partners, and is life-threatening to newborns. A vaccine that prevents genital herpes infection is a high public health priority. An ideal vaccine will prevent both genital lesions and asymptomatic subclinical infection to reduce the risk of inadvertent transmission to partners, will be effective against genital herpes caused by herpes simplex virus types 1 and 2 (HSV-1, HSV-2), and will protect against neonatal herpes. Three phase 3 human trials were performed over the past 20 years that used HSV-2 glycoproteins essential for virus entry as immunogens. None achieved its primary endpoint, although each was partially successful in either delaying onset of infection or protecting a subset of female subjects that were HSV-1 and HSV-2 uninfected against HSV-1 genital infection. The success of future vaccine candidates may depend on improving the predictive value of animal models by requiring vaccines to achieve near-perfect protection in these models and by using the models to better define immune correlates of protection. Many vaccine candidates are under development, including DNA, modified mRNA, protein subunit, killed virus, and attenuated live virus vaccines. Lessons learned from prior vaccine studies and select candidate vaccines are discussed, including a trivalent nucleoside-modified mRNA vaccine that our laboratory is pursuing. We are optimistic that an effective vaccine for prevention of genital herpes will emerge in this decade.

Herpes simplex virus type 2 trivalent protein vaccine containing glycoproteins C, D and E protects guinea pigs against HSV-1 genital infection

A vaccine to prevent genital herpes is an unmet public health need. We previously reported that a trivalent vaccine containing herpes simplex virus type 2 (HSV-2) glycoproteins C, D, and E (gC2, gD2, gE2) produced in baculovirus and administered with CpG/alum as adjuvants blocks immune evasion mediated by gC2 and gE2 and virus entry by gD2. The vaccine protected guinea pigs against HSV-2 vaginal infection. We evaluated whether the HSV-2 vaccine cross-protects against HSV-1 because many first-time genital herpes infections are now caused by HSV-1. Guinea pigs were mock immunized or immunized with the trivalent vaccine and challenged intravaginally with a different HSV-1 isolate in two experiments. Guinea pigs immunized with the trivalent vaccine developed genital lesions on fewer days than the mock group: 2/477 (0.4%) days compared to 15/424 (3.5%) in experiment one, and 0/135 days compared to 17/135 (12.6%) in experiment two (both P < .001). No animal in the trivalent group had HSV-2 DNA detected in vaginal secretions: 0/180 days for trivalent compared to 4/160 (2.5%) for mock (P < .05) in experiment one, and 0/65 days for trivalent compared to 4/65 (6%) for mock in experiment two. Therefore, a vaccine designed to prevent HSV-2 also protects against HSV-1 genital infection.