First estimates of the global and regional incidence of neonatal herpes infection

The Effect of Hormonal Contraception and Menstrual Cycle Timing on Genital Herpes Simplex Virus-2 Shedding and Lesions

BACKGROUND

The effect of female sex hormones on herpes simplex virus (HSV)-2 shedding and lesion frequency is poorly understood. Previous studies suggest that hormonal contraception may increase the frequency of HSV-2 shedding.

METHODS

We studied HSV-2 seropositive women who performed daily genital swabbing for HSV DNA and completed diaries for genital lesions and menses. We used Poisson mixed effects models to determine if HSV detection varied throughout the menstrual cycle, or in response to hormonal contraception. We used the Wilcoxon signed-rank test and rank-sum test to determine if lesion frequency differed by cycle phase or hormonal contraceptive use.

RESULTS

In 189 women aged 19 to 46 years who collected swabs on 10,715 days and were not using hormonal contraception, HSV-2 DNA was detected on 20.9% of days in the follicular phase and 17.8% of days in the luteal phase (rate ratio, 1.19; 95% confidence interval, 1.03-1.37, P = 0.02). Genital lesions did not differ in the follicular versus luteal phase (12.8% vs. 10.7%, P = 0.07). In analyses of hormonal contraception, including 244 women, HSV-2 DNA was detected on 19.0% of days for women not using hormonal contraception and 18.3% of days for those using hormonal contraception (P = 0.50). Lesions were present on 11.1% of days for women not using hormonal contraception, and 8.7% of days for those using hormonal contraception (P = 0.66).

CONCLUSIONS

In women with genital HSV-2 infection who are not using hormonal contraception, the follicular phase of the cycle may be associated with a higher frequency of HSV-2 shedding compared to the luteal phase. Lesion frequency is similar during the 2 menstrual phases. Hormonal contraception use was not observed to affect genital HSV-2 DNA detection or lesions.

Murine Model of Maternal Immunization Demonstrates Protective Role for Antibodies That Mediate Antibody-Dependent Cellular Cytotoxicity in Protecting Neonates From Herpes Simplex Virus Type 1 and Type 2

BACKGROUND

Neonatal herpes simplex virus (HSV) disease results in unacceptable morbidity and mortality. The primary humoral immune response to natural infection is neutralizing antibodies (Abs). However, Abs that activate Fc gama receptors (FcγRs) and mediate antibody-dependent cell-mediated cytotoxicity (ADCC) may play a dominant role in protection. In adult mice, a single-cycle HSV candidate vaccine deleted in glycoprotein-D (ΔgD-2) that induces ADCC provided complete protection against HSV disease and prevented the establishment of latency. Passive transfer studies showed that Abs were sufficient for protection. The current study tested the hypothesis that maternal immunization with ΔgD-2 would protect neonates.

METHODS

C57BL/6 female mice were vaccinated 3 weeks apart with ΔgD-2, and pups were challenged at different times postnatally with lethal doses of HSV-1 or HSV-2. Concentration and functionality of Abs and immune cells were assessed.

RESULTS

Maternal ΔgD-2 immunization provided significant protection and reduced viral dissemination after lethal challenge with HSV-1 or HSV-2. Protection correlated with Abs acquired transplacentally or from breastmilk that mediated ADCC. Protection was reduced when pups were challenged on Day 1 of life, and this was associated with decreased ability of newborn cells to mediate Ab-dependent cell killing.

CONCLUSIONS

Antibodies mediating ADCC provide significant protection against neonatal HSV.

Maternal infections

Congenital infections are infections transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum). They have the potential to adversely affect fetal development and long-term neurodevelopmental outcome through inflammatory, destructive, developmental, or teratogenic lesions of the brain. Because the fetal/neonatal brain has a limited capacity to respond to injury, early inflammatory changes may be difficult to visualize and only manifest as neurocognitive disability later in life. Teratogenic effects, which may include aberrations of neuronal proliferation and migration, are more easily visible on imaging, but may be equally difficult to use to predict long-term neurocognitive outcomes. This chapter reviews the general pathophysiology of congenital infection and describes the epidemiology, the antenatal and postnatal diagnosis, and the treatment of congenital infections as well as the long-term neurodevelopmental outcomes.

Vaccines for Herpes Simplex: Recent Progress Driven by Viral and Adjuvant Immunology

Herpes simplex viruses (HSV) types 1 and 2 are ubiquitous. They both cause genital herpes, occasionally severe disease in the immunocompromised, and facilitate much HIV acquisition globally. Despite more than 60 years of research, there is no licensed prophylactic HSV vaccine and some doubt as to whether this can be achieved. Nevertheless, a previous HSV vaccine candidate did have partial success in preventing genital herpes and HSV acquisition and another immunotherapeutic candidate reduced viral shedding and recurrent lesions, inspiring further research. However, the entry pathway of HSV into the anogenital mucosa and the subsequent cascade of immune responses need further elucidation so that these responses could be mimicked or improved by a vaccine, to prevent viral entry and colonization of the neuronal ganglia. For an effective novel vaccine against genital herpes the choice of antigen and adjuvant may be critical. The incorporation of adjuvants of the vaccine candidates in the past, may account for their partial efficacy. It is likely that they can be improved by understanding the mechanisms of immune responses elicited by different adjuvants and comparing these to natural immune responses. Here we review the history of vaccines for HSV, those in development and compare them to successful vaccines for chicken pox or herpes zoster. We also review what is known of the natural immune control of herpes lesions, via interacting innate immunity and CD4 and CD8 T cells and the lessons they provide for development of new, more effective vaccines.

Key Infections in the Placenta

Congenital infections are an important cause of morbidity and mortality worldwide, especially in low-income settings. This review discusses the main pathways of infections and associated adverse maternal and fetal outcomes, considering the TORCH pathogens, including Zika virus; the acronym stands for Toxoplasma gondii infection, other (Listeria monocytogenes, Treponema pallidum, and parvovirus B19, among others, including Zika virus), rubella virus, cytomegalovirus, and herpes simplex viruses type 1 and type 2.

Personalized viral genomic investigation of herpes simplex virus 1 perinatal viremic transmission with dual fatality

Here we present a personalized viral genomics approach to investigating a rare case of perinatal herpes simplex virus 1 (HSV-1) transmission that ended in death of both mother and neonate. We sought to determine whether the virus involved in this rare case had any unusual features that may have contributed to the dire patient outcome. A pregnant woman with negative HerpeSelect antibody test underwent cesarean section at 30 wk gestation and died the same day. The premature newborn died 5 d later. Both individuals were found postmortem to have positive blood HSV-1 PCR tests. Using oligonucleotide enrichment and deep sequencing, we determined that viral transmission from mother to infant was nearly perfect at the consensus genome level. At the virus population level, 77% of minor variants (MVs) in the mother's blood also appeared on the neonate's skin, of which more than half were disseminated into the neonate's blood. We also detected nonmaternal MVs that arose de novo in the neonate's viral populations. Of note, one de novo MV in the neonate's skin virus induced a nonsynonymous mutation in the UL6 protein, which is a component of the portal that allows DNA entry into new progeny capsids. This case suggests that perinatal viremic HSV-1 transmission includes the majority of genetic diversity from the maternal virus population and that new, nonsynonymous mutations can occur after relatively few rounds of replication. This report expands our understanding of viral transmission in humans and may lead to improved diagnostic strategies for neonatal HSV-1 acquisition.

Viral genetic diversity and its potential contributions to the development and progression of neonatal herpes simplex virus (HSV) disease

PURPOSE OF REVIEW

Neonatal infection by herpes simplex virus (HSV) 1 or 2 presents a devastating burden to new parents, due to the unpredictability of severe clinical outcomes, as well as the potential for lifelong reactivation. While just under half of neonatal HSV infections have mild clinical impacts akin to those observed in adults, the other half experience viral spread throughout the body (disseminated infection) and/or the brain (central nervous system infection).

SUMMARY

Here we summarize current data on clinical diagnostic measures, antiviral therapy, and known factors of human host biology that contribute to the distinct neonatal outcomes of HSV infection.

RECENT FINDINGS

We then explore recent new data on how viral genetic diversity between infections may impact clinical outcomes. Further research will be critical to build upon these early findings and to provide statistical power to our ability to discern and/or predict the potential clinical path of a given neonatal infection.

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.

Modelling efforts needed to advance herpes simplex virus (HSV) vaccine development: Key findings from the World Health Organization Consultation on HSV Vaccine Impact Modelling

Development of a vaccine against herpes simplex virus (HSV) is an important goal for global sexual and reproductive health. In order to more precisely define the health and economic burden of HSV infection and the theoretical impact and cost-effectiveness of an HSV vaccine, in 2015 the World Health Organization convened an expert consultation meeting on HSV vaccine impact modelling. The experts reviewed existing model-based estimates and dynamic models of HSV infection to outline critical future modelling needs to inform development of a comprehensive business case and preferred product characteristics for an HSV vaccine. This article summarizes key findings and discussions from the meeting on modelling needs related to HSV burden, costs, and vaccine impact, essential data needs to carry out those models, and important model components and parameters.

Host Intrinsic and Innate Intracellular Immunity During Herpes Simplex Virus Type 1 (HSV-1) Infection

When host cells are invaded by viruses, they deploy multifaceted intracellular defense mechanisms to control infections and limit the damage they may cause. Host intracellular antiviral immunity can be classified into two main branches: (i) intrinsic immunity, an interferon (IFN)-independent antiviral response mediated by constitutively expressed cellular proteins (so-called intrinsic host restriction factors); and (ii) innate immunity, an IFN-dependent antiviral response conferred by IFN-stimulated gene (ISG) products, which are (as indicated by their name) upregulated in response to IFN secretion following the recognition of pathogen-associated molecular patterns (PAMPs) by host pattern recognition receptors (PRRs). Recent evidence has demonstrated temporal regulation and specific viral requirements for the induction of these two arms of immunity during herpes simplex virus type 1 (HSV-1) infection. Moreover, they exert differential antiviral effects to control viral replication. Although they are distinct from one another, the words "intrinsic" and "innate" have been interchangeably and/or simultaneously used in the field of virology. Hence, the aims of this review are to (1) elucidate the current knowledge about host intrinsic and innate immunity during HSV-1 infection, (2) clarify the recent advances in the understanding of their regulation and address the distinctions between them with respect to their induction requirements and effects on viral infection, and (3) highlight the key roles of the viral E3 ubiquitin ligase ICP0 in counteracting both aspects of immunity. This review emphasizes that intrinsic and innate immunity are temporally and functionally distinct arms of host intracellular immunity during HSV-1 infection; the findings are likely pertinent to other clinically important viral infections.

Maintaining Breastfeeding During Severe Infant and Maternal HSV-1 Infection: A Case Report

INTRODUCTION

Childbearing women with primary or secondary Herpes Simplex Virus type 1 infection are at risk of transmitting neonatal herpes infection to their infants; a medical emergency that is associated with high mortality and morbidity. Neonatal herpes infection has been commonly associated with Herpes Simplex Virus type 2, or genital herpes, but can be caused by either subtype and the presentations are indistinguishable. This case describes the course of diagnosis, treatment, and recovery for a mother and infant during a severe maternal and neonatal herpes infection, and how lactation was maintained and breastfeeding re-established. Our children's hospital coordinated its efforts to assist and monitor this breastfeeding family, and they were able to resume breastfeeding soon after discharge. It is our opinion that it is imperative that mothers receive evidence-based lactation care to maintain their breastfeeding relationship during extended hospital stays.

MAIN ISSUE

An acutely ill infant was admitted to our urban children's hospital with severe neonatal herpes infection for a total of 3 weeks. His mother was severely affected on her breasts and she required a brief hospitalization. The mother's breasts were covered with draining herpetic lesions that required daily dressing changes. However, her lesions were slow to heal, and a wound care consultation was facilitated and her treatment plan was adjusted. We were surprised that she experienced minimal discomfort with pumping and dressing changes. The mother maintained a positive outlook, complied with the plan to express frequently to maintain milk production, and was able to breastfeed again when they both recovered.

MANAGEMENT

This mother received immediate support and appropriate pumping equipment from our hospital personnel and was subsequently able to establish and maintain her milk supply. The difficulty in this case was the management of the mother's extensive herpetic wounds that were slow to heal. A certified wound care specialist was required. Both mother and child recovered from their infections and were able to restart breastfeeding; eventually reaching their goal of breastfeeding for 2 years.

CONCLUSIONS

Neonatal herpes infection is a potentially fatal disease and maternal child health professionals should have a high suspicion for any ill-appearing newborn with or without a rash. When a breastfeeding infant and mother become infected with Herpes Simplex Virus type 1, it is the responsibility of the healthcare institution to support lactation and the return to breastfeeding rather than recommend cessation of lactation, which is rarely necessary. A multi-disciplinary evidence-based approach to lactation care is essential to preserve lactation during infant hospitalization.

Persistent Infection with Herpes Simplex Virus 1 and Alzheimer's Disease-A Call to Study How Variability in Both Virus and Host may Impact Disease

Increasing attention has focused on the contributions of persistent microbial infections with the manifestation of disease later in life, including neurodegenerative conditions such as Alzheimer’s disease (AD). Current data has shown the presence of herpes simplex virus 1 (HSV-1) in regions of the brain that are impacted by AD in elderly individuals. Additionally, neuronal infection with HSV-1 triggers the accumulation of amyloid beta deposits and hyperphosphorylated tau, and results in oxidative stress and synaptic dysfunction. All of these factors are implicated in the development of AD. These data highlight the fact that persistent viral infection is likely a contributing factor, rather than a sole cause of disease. Details of the correlations between HSV-1 infection and AD development are still just beginning to emerge. Future research should investigate the relative impacts of virus strain- and host-specific factors on the induction of neurodegenerative processes over time, using models such as infected neurons in vitro, and animal models in vivo, to begin to understand their relationship with cognitive dysfunction.

Factors Associated With HSV PCR CSF Testing and Empiric Acyclovir Therapy in Young Febrile Infants

Herpes simplex virus (HSV) infection in infants is a devastating disease with an often subtle presentation. We examined cerebrospinal fluid (CSF) HSV PCR (polymerase chain reaction) testing and empiric acyclovir therapy in young febrile infants. Chart review identified hospitalized infants aged ≤60 days with fever ≥38°C who had undergone lumbar puncture. Previously published criteria were used to define patients at high risk for HSV. Primary outcomes were CSF HSV PCR testing and empiric acyclovir therapy. Of 536 febrile infants, 23% had HSV testing; empiric acyclovir was started in 15%. HSV testing and therapy were associated with younger age, seizure, maternal vaginal lesions, postnatal HSV contact, vesicles, poor tone, CSF pleocytosis, and enteroviral testing. Sixty-two percent of high-risk infants did not undergo HSV testing, and 75% did not receive acyclovir. High-risk infants were untested and untreated at relatively high rates. Evidence-based criteria to guide HSV testing and treatment are needed.

Contriving a chimeric polyvalent vaccine to prevent infections caused by herpes simplex virus (type-1 and type-2): an exploratory immunoinformatic approach

Herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) cause a variety of infections including oral-facial infections, genital herpes, herpes keratitis, cutaneous infection and so on. To date, FDA-approved licensed HSV vaccine is not available yet. Hence, the study was conducted to identify and characterize an effective epitope based polyvalent vaccine against both types of Herpes Simplex Virus. The selected proteins were retrieved from ViralZone and assessed to design highly antigenic epitopes by binding analyses of the peptides with MHC class-I and class-II molecules, antigenicity screening, transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis and molecular docking approach. The final vaccine was constructed by the combination of top CTL, HTL and BCL epitopes from each protein along with suitable adjuvant and linkers. Physicochemical and secondary structure analysis, disulfide engineering, molecular dynamic simulation and codon adaptation were further employed to develop a unique multi-epitope peptide vaccine. Docking analysis of the refined vaccine structure with different MHC molecules and human immune TLR-2 receptor demonstrated higher interaction. Complexed structure of the modeled vaccine and TLR-2 showed minimal deformability at molecular level. Moreover, translational potency and microbial expression of the modeled vaccine was analyzed with pET28a(+) vector for E. coli strain K12 and the vaccine constructs had no similarity with entire human proteome. The study enabled design of a novel chimeric polyvalent vaccine to confer broad range immunity against both HSV serotypes. However, further wet lab based research using model animals are highly recommended to experimentally validate our findings.Communicated by Ramaswamy H. Sarma.

Mortality from neonatal herpes simplex viremia causing severe hepatitis

Neonatal herpes simplex viral infections are rare in the setting of appropriate prenatal care; however, under circumstances where prenatal care is not delivered, these infections can lead to significant disease. We report a fatal case of herpes simplex virus with severe herpes hepatitis in a 14-day old male neonate. The clinical history was limited and nonspecific, however there was no prenatal care and a known history of drug abuse in the family. Autopsy revealed extensive necrosis and hemorrhage of the liver and cerebellum. Histologically, the liver revealed viral intranuclear ground glass inclusions, characteristic of herpes virus. Immunohistochemistry for herpes simplex virus performed on the both the liver and cerebellum showed strong diffuse staining in the liver and negative staining in the cerebellum. Neonatal herpes simplex virus infection is a disease of low prevalence with significant morbidity and mortality, and an exceptionally high rate of fatality in those with disseminated disease with associated fulminant hepatic failure.

Characteristics of herpes simplex virus infection and pathogenesis suggest a strategy for vaccine development

Herpes simplex virus (HSV) can cause oral or genital ulcerative lesions and even encephalitis in various age groups with high infection rates. More seriously, HSV may lead to a wide range of recurrent diseases throughout a lifetime. No vaccines against HSV are currently available. The accumulated clinical research data for HSV vaccines reveal that the effects of HSV interacting with the host, especially the host immune system, may be important for the development of HSV vaccines. HSV vaccine development remains a major challenge. Thus, we focus on the research data regarding the interactions of HSV and host immune cells, including dendritic cells (DCs), innate lymphoid cells (ILCs), macrophages, and natural killer (NK) cells, and the related signal transduction pathways involved in immune evasion and cytokine production. The aim is to explore possible strategies to develop new effective HSV vaccines.

Does voluntary medical male circumcision protect against sexually transmitted infections among men and women in real-world scale-up settings? Findings of a household survey in KwaZulu-Natal, South Africa

INTRODUCTION

Male circumcision (MC) confers partial protection to men against HIV and, in research settings, some sexually transmitted infections (STIs). It is also associated with protection from some STIs among female partners. However, real-world data on changes in STI transmission associated with large-scale public African medical male circumcision (MMC) conducted for HIV prevention are lacking and would improve estimates of the health impact of MMC.

METHODS

The HIV Incidence Provincial Surveillance System is a community-based surveillance platform for HIV prevalence, incidence and intervention coverage trends in KwaZulu-Natal province, South Africa. HIPPS collected cross-sectional self-reported data on circumcision status (from men), partner circumcision status for past three partners (from women) and demographic characteristics and behavioural risk factors; and tested participants for HIV, herpes simplex virus type 2 (HSV-2), syphilis, hepatitis B, N eisseria gonorrhoeae, C hlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium. Bivariable and multivariable analyses were performed on associations between own (men) or partner's (women) circumcision status and each STI. Multivariable analyses adjusted for age, demographic characteristics and behavioural risk factors, and incorporated false discovery rate (FDR) correction.

RESULTS

Among men, MMC had a protective association with HSV-2 (OR 0.66, 95% CI 0.50 to 0.86), hepatitis B (OR 0.53, 95% CI 0.30 to 0.95), HIV (OR 0.50, 95% CI 0.38 to 0.65) and M. genitalium (OR 0.53, 95% CI 0.32 to 0.88). Among women, partner circumcision had a protective association with HSV-2 (OR 0.71, 95% CI 0.53 to 0.95) and HIV (OR 0.66, 95% CI 0.49 to 0.90). Associations with HIV and HSV-2 remained significant for men and all women after FDR correction.

CONCLUSION

These real-world data, supporting protective associations between MMC conducted for HIV prevention and STIs in men and women, can help clarify the full impact of MMC and support a role in broader sexual health programming.

[Mechanisms of herpes simplex virus latency and reactivation]

Herpes simplex virus (HSV), including HSV-1 and HSV-2, is an important pathogen that can cause many diseases. Usually these diseases are recurrent and incurable. After lytic infection on the surface of peripheral mucosa, HSV can enter sensory neurons and establish latent infection during which viral replication ceases. Moreover, latent virus can re-enter the replication cycle by reactivation and return to peripheral tissues to start recurrent infection. This ability to escape host immune surveillance during latent infection and to spread during reactivation is a viral survival strategy and the fundamental reason why no drug can completely eradicate the virus at present. Although there are many studies on latency and reactivation of HSV, and much progress has been made, many specific mechanisms of the process remain obscure or even controversial due to the complexity of this process and the limitations of research models. This paper reviews the major results of research on HSV latency and reactivation, and discusses future research directions in this field.

Trends in the incidence, mortality, and cost of neonatal herpes simplex virus hospitalizations in the United States from 2003 to 2014

OBJECTIVE

To examine the temporal trends in the incidence and outcomes of neonatal herpes simplex infections (NHSV) in the United States.

STUDY DESIGN

We conducted a retrospective study using the National Inpatient Sample (NIS). Neonates ≤28 days old with ICD-9 codes for NHSV (054.xx) from 2003 to 2014 were included. Trends in the incidence, mortality, length of stay (LOS), and hospital cost were analyzed using Jonckheere-Terpstra test.

RESULTS

NHSV increased from 7.9 to 10 per 100,000 live births from 2003-05 to 2012-14 (P = 0.04). Hospital costs increased from $21,650 to $27,843; P < 0.001). The overall mortality rate and median LOS were 7.9% and 20 days, respectively and there were no significant variations across years during the study period.

CONCLUSIONS

The incidence of NHSV in the United States increased between 2003 and 2014 without a significant change in mortality. NHSV remains a serious health threat and new and effective strategies to prevent NHSV are needed.

HSV-2-encoded miRNA-H4 Regulates Cell Cycle Progression and Act-D-induced Apoptosis in HeLa Cells by Targeting CDKL2 and CDKN2A

MicroRNAs (miRNAs) encoded by latency-associated transcript are associated with both latent and acute stages of herpes simplex virus 2 (HSV-2) infection. In this study, miRNA-H4-5p and miRNA-H4-3p were ectopically expressed in HeLa cells to explore potential cellular targets of viral miRNAs and demonstrate their potential biological functions. The results showed that miRNA-H4-5p could reverse apoptosis induced by actinomycin D (Act-D) and promote cell cycle progression, but miRNA-H4-3p had no such obvious functions. Bioinformatics analysis, luciferase report assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and Western blotting demonstrated that miRNA-H4-5p could bind to the 3'-untranslated region (UTR) of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase-like 2 (CDKL2) to negatively regulate their expression. We verified that these two targeted genes were associated with cell apoptosis and cell cycle. Furthermore, in HeLa cells infected with HSV-2, we detected significantly reduced expression of CDKN2A and CDKL2 and demonstrated the negative regulation effect of miRNA-H4-5p on these two target genes. Our findings show that viral miRNAs play a vital role in regulating the expression of the host's cellular genes that participate in cell apoptosis and progression to reshape the cellular environment in response to HSV-2 infection, providing further information on the roles of encoded herpesvirus miRNAs in pathogen-host interaction.

Neonatal Herpes Simplex Virus Infection Among Medicaid-Enrolled Children: 2009-2015

OBJECTIVES

To examine the incidence, mortality, and health care use related to neonatal herpes simplex virus (HSV) infection.

METHODS

A retrospective longitudinal cohort study using a multistate Medicaid claims database. We identified neonates hospitalized with HSV infection from 2009 to 2015 by using discharge diagnosis codes and managed them for 6 months after discharge. Incidence rates were corrected for the imperfect sensitivity and specificity of thediagnosis codes for identifying HSV infection.

RESULTS

Of 2 107 124 births from 2009 to 2015, 900 neonates were identified with HSV infection, with a corrected incidence rate of 4.5 (95% confidence interval [CI]: 4.2-4.8) per 10 000 births. The yearly disease incidence increased by 56%, from 3.4 (95% CI: 2.8-4.2) per 10 000 births (or 1 in 2941 births) in 2009 to 5.3 (95% CI: 4.6-6.1) per 10 000 births (or 1 in 1886 births) in 2015 (P < .001). Of the 900 neonates with HSV infection, 54 (6.0% [95% CI: 4.4%-7.6%]) died during the index hospitalization; there was no increase in the yearly mortality rate. Of the 692 (81.2%) infants with follow-up data, 316 (45.7%) had an emergency department visit, and 112 (16.2%) had a hospital readmission. Total payments at 6 months amounted to $60 620 431, a median of $87 602 per case of neonatal HSV infection.

CONCLUSIONS

We observed an increase in neonatal HSV infection incidence over a recent 7-year period in a Medicaid population. Associated health care use and payments were substantial. Public health interventions targeting disease prevention and early diagnosis are needed.

Mechanisms of Immune Control of Mucosal HSV Infection: A Guide to Rational Vaccine Design

Herpes Simplex Virus (HSV) is a highly prevalent sexually transmitted infection that aside from causing cold sores and genital lesions, causes complications in the immunocompromised and has facilitated a large proportion of HIV acquisition globally. Despite decades of research, there is no prophylactic HSV vaccine ready for use in humans, leaving many questioning whether a prophylactic vaccine is an achievable goal. A previous HSV vaccine trial did have partial success in decreasing acquisition of HSV2–promising evidence that vaccines can prevent acquisition. However, there is still an incomplete understanding of the immune response pathways elicited by HSV after initial mucosal infection and how best to replicate these responses with a vaccine, such that acquisition and colonization of the dorsal root ganglia could be prevented. Another factor to consider in the rational design of an HSV vaccine is adjuvant choice. Understanding the immune responses elicited by different adjuvants and whether lasting humoral and cell-mediated responses are induced is important, especially when studies of past trial vaccines found that a sufficiently protective cell-mediated response was lacking. In this review, we discuss what is known of the immune control involved in initial herpes lesions and reactivation, including the importance of CD4 and CD8 T cells, and the interplay between innate and adaptive immunity in response to primary infection, specifically focusing on the viral relay involved. Additionally, a summary of previous and current vaccine trials, including the components used, immune responses elicited and the feasibility of prophylactic vaccines looking forward, will also be discussed.

Genotypic and Phenotypic Diversity of Herpes Simplex Virus 2 within the Infected Neonatal Population

More than 14,000 neonates are infected with herpes simplex virus (HSV) annually. Approximately half display manifestations limited to the skin, eyes, or mouth (SEM disease). The rest develop invasive infections that spread to the central nervous system (CNS disease or encephalitis) or throughout the infected neonate (disseminated disease). Invasive HSV disease is associated with significant morbidity and mortality, but the viral and host factors that predispose neonates to these forms are unknown. To define viral diversity within the infected neonatal population, we evaluated 10 HSV-2 isolates from newborns with a range of clinical presentations. To assess viral fitness independently of host immune factors, we measured viral growth characteristics in cultured cells and found diverse in vitro phenotypes. Isolates from neonates with CNS disease were associated with larger plaque size and enhanced spread, with the isolates from cerebrospinal fluid (CSF) exhibiting the most robust growth. We sequenced complete viral genomes of all 10 neonatal viruses, providing new insights into HSV-2 genomic diversity in this clinical setting. We found extensive interhost and intrahost genomic diversity throughout the viral genome, including amino acid differences in more than 90% of the viral proteome. The genes encoding glycoprotein G (gG; US4), glycoprotein I (gI; US7), and glycoprotein K (gK; UL53) and viral proteins UL8, UL20, UL24, and US2 contained variants that were found in association with CNS isolates. Many of these viral proteins are known to contribute to cell spread and neurovirulence in mouse models of CNS disease. This report represents the first application of comparative pathogen genomics to neonatal HSV disease.IMPORTANCE Herpes simplex virus (HSV) causes invasive disease in half of infected neonates, resulting in significant mortality and permanent cognitive morbidity. The factors that contribute to invasive disease are not understood. This study revealed diversity among HSV isolates from infected neonates and detected the first associations between viral genetic variations and clinical disease manifestations. We found that viruses isolated from newborns with encephalitis showed enhanced spread in culture. These viruses contained protein-coding variations not found in viruses causing noninvasive disease. Many of these variations were found in proteins known to impact neurovirulence and viral spread between cells. This work advances our understanding of HSV diversity in the neonatal population and how it may impact disease outcome.

Fatal Disseminated Herpes Simplex in a very premature neonate

Herpes Simplex Virus infections (HSV) are ubiquitous. The neonatal HSV infection (NHSV) is rare. The incidence is estimated globally at only 10.3 per 100,000 births, but it can cause devastating disease in premature infants. Both HSV-1 and HSV-2 can be the etiologic agents in this type of vertically transmittted NHSV infection. Here we describe the pathological findings from a complete autopsy of a very low birth weight infant who succumbed to the infection despite early institution of antiviral treatment. We urge more awareness of this disease with continued surveillance; every effort should be taken to make an early diagnosis and thus prevent this devastating disease.

The antiviral activity of arbidol hydrochloride against herpes simplex virus type II (HSV-2) in a mouse model of vaginitis

Objective

HSV-2 infection has increased significantly in recent years, which is closely associated with cervical cancer and HIV infection. The lack of success in vaccine development and the emergence of drug resistance to commonly used drugs emphasize the urgent need for alternative antivirals against HSV-2 infection. Arbidol (ARB) has been demonstrated to be a broad spectrum antiviral drug that exhibits immunomodulatory properties that affect the HSV-2 life cycle. This study investigated the efficacy and mechanism of ARB against HSV-2 in vivo and in vitro to further explore the clinical application of ARB.

Methods

The efficacy of ARB on HSV-2 infection in vitro was examined by CPE and MTT assays. A vaginitis model was established to monitor changes in histopathology and inflammatory cytokine (IL-2, IL-4, TNF-α and TGF-β) expression by H&E staining and ELISA, respectively, and the efficacy of ARB was evaluated accordingly. Furthermore, flow cytometry was used to determine the ratio of CD4⁺/CD8⁺ T cells in the peripheral blood of the vaginitis animals. Considering the balance of efficacy and pharmacokinetics, ARB ointment was strictly prepared to observe formulation efficacy differences compared to the oral dosing form.

Results

The results showed that, in vitro, the TC₅₀ and IC₅₀ of ARB were 32.32 μg/mL and 4.77 μg/mL (SI = 6.82), respectively, indicating that ARB presents effective activity against HSV-2 in a dose-dependent manner. The results of the time-course assay suggested that 25 μg/mL ARB affected the late stage of HSV-2 replication. However, ARB did not inhibit viral attachment or cell penetration. The in vivo results showed that ARB ointment can improve the survival rate, prolong the survival time and reduce the reproductive tract injury in mice infected with HSV-2, regulate cytokine expression; and balance the CD4⁺ and CD8⁺ T lymphocyte ratio in the peripheral blood to participate in the regulation of immune response.

Conclusion

ARB showed anti-HSV-2 activity in vitro in a dose-dependent manner and played a role in inhibiting the late replication cycle of the virus. The vaginitis model was successfully established, according to immunomodulation outcomes, responded better to ARB in ointment form than in oral form.

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ARB showed anti-HSV-2 activity in vitro in a dose-dependent manner.

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ARB inhibited the late replication cycle of HSV-2.

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ARB ointment participated in the regulation of immune response to reduce the reproductive tract injury.

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ARB in ointment form responded to vaginitis better than in oral form.

Development of disease and immunity at the genital epithelium following intrarectal inoculation of male guinea pigs with herpes simplex virus type 2

Most analyses of genital immunity to herpes simplex virus type 2 (HSV-2) have been performed in females, consequently immune protection of the male genital epithelium is incompletely understood. We developed a model of male genital HSV-2 infection resulting from intrarectal inoculation of guinea pigs. Vesicular lesions developed transiently on the perineum and foreskin concurrent with acute virus shedding. Virus shedding and recurrent genital lesions were also detected after establishment of a latent infection. Analysis of perineum and foreskin RNA detected transcripts for IFNγ, proinflammatory and regulatory cytokines, and for genes involved in migration and regulation of leukocytes. HSV-specific T cells were detected in lymphoid and genital tissues after resolution of the primary infection whereas virus-specific antibody secreting cells were detected only in lymphoid tissue. Taken together, the ability to quantify pathogenesis and local immunity in this guinea pig model represent an important advance towards understanding immunity to HSV-2 in males.

Clinical management of herpes simplex virus infections: past, present, and future

Infection with herpes simplex virus (HSV) types 1 and 2 is ubiquitous in the human population. Most commonly, virus replication is limited to the epithelia and establishes latency in enervating sensory neurons, reactivating periodically to produce localized recurrent lesions. However, these viruses can also cause severe disease such as recurrent keratitis leading potentially to blindness, as well as encephalitis, and systemic disease in neonates and immunocompromised patients. Although antiviral therapy has allowed continual and substantial improvement in the management of both primary and recurrent infections, resistance to currently available drugs and long-term toxicity pose a current and future threat that should be addressed through the development of new antiviral compounds directed against new targets. The development of several promising HSV vaccines has been terminated recently because of modest or controversial therapeutic effects in humans. Nevertheless, several exciting vaccine candidates remain in the pipeline and are effective in animal models; these must also be tested in humans for sufficient therapeutic effects to warrant continued development. Approaches using compounds that modulate the chromatin state of the viral genome to suppress infection and reactivation or induce enhanced antiviral immunity have potential. In addition, technologies such as CRISPR/Cas9 have the potential to edit latent viral DNA in sensory neurons, potentially curing the neuron and patient of latent infection. It is hoped that development on all three fronts—antivirals, vaccines, and gene editing—will lead to substantially less HSV morbidity in the future.

Qualitative Differences in Capsidless L-Particles Released as a By-Product of Bovine Herpesvirus 1 and Herpes Simplex Virus 1 Infections

The alphaherpesvirus family includes viruses that infect humans and animals. Hence, not only do they have a significant impact on human health, but they also have a substantial economic impact on the farming industry. While the pathogenic manifestations of the individual viruses differ from host to host, their relative genetic compositions suggest similarity at the molecular level. This study provides a side-by-side comparison of the particle outputs from the major human pathogen HSV-1 and the veterinary pathogen BoHV-1. Ultrastructural and proteomic analyses have revealed that both viruses have broadly similar morphogenesis profiles and infectious virus compositions. However, the demonstration that BoHV-1 has the capacity to generate vast numbers of capsidless enveloped particles that differ from those produced by HSV-1 in composition implies a divergence in the cell biology of these viruses that impacts our general understanding of alphaherpesvirus morphogenesis.

Despite differences in the pathogenesis and host range of alphaherpesviruses, many stages of their morphogenesis are thought to be conserved. Here, an ultrastructural study of bovine herpesvirus 1 (BoHV-1) envelopment revealed profiles similar to those previously found for herpes simplex virus 1 (HSV-1), with BoHV-1 capsids associating with endocytic tubules. Consistent with the similarity of their genomes and envelopment strategies, the proteomic compositions of BoHV-1 and HSV-1 virions were also comparable. However, BoHV-1 morphogenesis exhibited a diversity in envelopment events. First, heterogeneous primary envelopment profiles were readily detectable at the inner nuclear membrane of BoHV-1-infected cells. Second, the BoHV-1 progeny comprised not just full virions but also an abundance of capsidless, noninfectious light particles (L-particles) that were released from the infected cells in numbers similar to those of virions and in the absence of DNA replication. Proteomic analysis of BoHV-1 L-particles and the much less abundant HSV-1 L-particles revealed that they contained the same complement of envelope proteins as virions but showed variations in tegument content. In the case of HSV-1, the U_L46 tegument protein was reproducibly found to be >6-fold enriched in HSV-1 L-particles. More strikingly, the tegument proteins U_L36, U_L37, U_L21, and U_L16 were depleted in BoHV-1 but not HSV-1 L-particles. We propose that these combined differences reflect the presence of truly segregated “inner” and “outer” teguments in BoHV-1, making it a critical system for studying the structure and process of tegumentation and envelopment.

IMPORTANCE The alphaherpesvirus family includes viruses that infect humans and animals. Hence, not only do they have a significant impact on human health, but they also have a substantial economic impact on the farming industry. While the pathogenic manifestations of the individual viruses differ from host to host, their relative genetic compositions suggest similarity at the molecular level. This study provides a side-by-side comparison of the particle outputs from the major human pathogen HSV-1 and the veterinary pathogen BoHV-1. Ultrastructural and proteomic analyses have revealed that both viruses have broadly similar morphogenesis profiles and infectious virus compositions. However, the demonstration that BoHV-1 has the capacity to generate vast numbers of capsidless enveloped particles that differ from those produced by HSV-1 in composition implies a divergence in the cell biology of these viruses that impacts our general understanding of alphaherpesvirus morphogenesis.

Polyethylene glycol-coated zinc oxide nanoparticle: an efficient nanoweapon to fight against herpes simplex virus type 1

AIM

We aimed to determine the possible inhibitory effects of zinc oxide nanoparticles (ZnO-NPs) and polyethylene glycol (PEG)-coated ZnO-NPs (ZnO-PEG-NPs) on herpes simplex virus type 1 (HSV-1).

MATERIALS & METHODS

PEGylated ZnO-NPs were synthesized by the mechanical method. Antiviral activity was assessed by 50% tissue culture infectious dose (TCID₅₀) and real-time PCR assays. To confirm the antiviral activity of ZnO-NPs on expression of HSV-1 antigens, indirect immunofluorescence assay was also conducted.

RESULTS

200 μg/ml ZnO-PEG-NPs could result in 2.5 log₁₀ TCID₅₀ reduction in virus titer, with inhibition rate of approximately 92% in copy number of HSV-1 genomic DNA.

CONCLUSION

ZnO-PEG-NPs could be proposed as a new agent for efficient HSV-1 inhibition. Our results indicated that PEGylation is effective in reducing cytotoxicity and increasing antiviral activity of nanoparticles.

Bowman‒Birk Inhibitor Suppresses Herpes Simplex Virus Type 2 Infection of Human Cervical Epithelial Cells

The Bowman‒Birk inhibitor (BBI), a protease inhibitor derived from soybeans, has been extensively studied in anti-tumor and anti-inflammation research. We recently reported that BBI has an anti-HIV-1 property in primary human macrophages. Because HSV-2 infection plays a role in facilitating HIV-1 sexual transmission, we thus examined whether BBI has the ability to inhibit HSV-2 infection. We demonstrated that BBI could potently inhibit HSV-2 replication in human cervical epithelial cells (End1/E6E7). This BBI-mediated HSV-2 inhibition was partially through blocking HSV-2-mediated activation of NF-κB and p38 MAPK pathways. In addition, BBI could activate the JAK/STAT pathway and enhance the expression of several antiviral interferon-stimulated genes (ISGs). Furthermore, BBI treatment of End1/E6E7 cells upregulated the expression of tight junction proteins and reduced HSV-2-mediated cellular ubiquitinated proteins’ degradation through suppressing the ubiquitin‒proteasome system. These observations indicate that BBI may have therapeutic potential for the prevention and treatment of HSV-2 infections.

Sexually transmitted infections during pregnancy and subsequent risk of stillbirth and infant mortality in Kenya: a prospective study

OBJECTIVES

We evaluated the relationship of sexually transmitted infections (STIs) and genital infections during pregnancy and subsequent risk for infant mortality and stillbirth.

METHODS

This was a nested longitudinal analysis using data from a study of peripartum HIV acquisition in Kenya. In the parent study, HIV-uninfected women were enrolled during pregnancy and followed until 9 months postpartum. For this analysis, women who tested positive for HIV at any point, had a non-singleton pregnancy or a spontaneous abortion <20 weeks were excluded. At enrolment, laboratory methods were used to screen for bacterial vaginosis (BV), vaginal yeast, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV). Syphilis was diagnosed using rapid plasma reagin testing and genital ulcer disease (GUD) identified by clinical examination. Treatment of laboratory-confirmed STIs and syndromic management was provided per Kenyan national guidelines. Predictors of stillbirth and infant mortality were determined using logistic regression and Cox proportional hazards models.

RESULTS

Overall, among 1221 women, 55% had STIs or genital infections detected: vaginal yeast (25%), BV (22%), TV (6%), CT (5%), NG (2%) and syphilis (1%). Among women with STIs/genital infections (n=592), 34% had symptoms. Overall, 19/1221 (2%) women experienced stillbirths. Among 1202 live births, 34 infant deaths occurred (incidence 4.0 deaths per 100 person-years, 95% CI 2.8 to 5.5). After adjustment for maternal age, education and study site, stillbirth was associated with maternal GUD (adjusted OR=9.19, 95% CI1.91 to 44.35, p=0.006). Maternal NG was associated with infant mortality (adjusted HR=3.83, 95% CI1.16 to 12.68, p=0.028); there was some evidence that maternal CT was associated with infant mortality. Stillbirth or infant mortality were not associated with other genital infections.

CONCLUSIONS

STIs and genital infections were common, frequently asymptomatic and some associated with stillbirth or infant mortality. Expediting diagnosis and treatment of STIs in pregnancy may improve infant outcomes.

Insights into the pathogenesis of herpes simplex encephalitis from mouse models

A majority of the world population is infected with herpes simplex viruses (HSV; human herpesvirus types 1 and 2). These viruses, perhaps best known for their manifestation in the genital or oral mucosa, can also cause herpes simplex encephalitis, a severe and often fatal disease of the central nervous system. Antiviral therapies for HSV are only partially effective since the virus can establish latent infections in neurons, and severe pathological sequelae in the brain are common. A better understanding of disease pathogenesis is required to develop new strategies against herpes simplex encephalitis, including the precise viral and host genetic determinants that promote virus invasion into the central nervous system and its associated immunopathology. Here we review the current understanding of herpes simplex encephalitis from the host genome perspective, which has been illuminated by groundbreaking work on rare herpes simplex encephalitis patients together with mechanistic insight from single-gene mouse models of disease. A complex picture has emerged, whereby innate type I interferon-mediated antiviral signaling is a central pathway to control viral replication, and the regulation of immunopathology and the balance between apoptosis and autophagy are critical to disease severity in the central nervous system. The lessons learned from mouse studies inform us on fundamental defense mechanisms at the interface of host–pathogen interactions within the central nervous system, as well as possible rationales for intervention against infections from severe neuropathogenic viruses.

Update on Neonatal Herpes Simplex Epidemiology in the Netherlands: A Health Problem of Increasing Concern?

BACKGROUND

This article provides an update on the incidence of neonatal herpes, guideline adherence by health care professionals (HCP) and trends in genital herpes simplex virus (HSV) infection during pregnancy in the Netherlands.

METHODS

Questionnaires were sent to all hospitals inquiring about numbers and characteristics of neonatal and maternal HSV infections, and guideline adherence between 2012 and 2015. Longitudinal trends were investigated from 1999 onward using survey data and Perinatal Registry of the Netherlands data (Perined). Trends were smoothed with Poisson regression splines. Risk indicators for neonatal and maternal HSV infections were examined with Poisson regression analyses.

RESULTS

Neonatal herpes incidence was 4.8/100,000 live births based on survey data (2012-2015) and 3.4/100,000 based on Perined (2012-2014). Mortality rate was 23% (7/30). Neonatal herpes incidence increased slightly over time as did the prevalence of genital HSV infection among pregnant women. Non-Western ethnicity (Rate Ratio: 1.9; 95% confidence interval: 1.5-2.5) and age <20 years (Rate Ratio: 2.3; 95% confidence interval: 1.2-4.7) were associated with genital herpes during pregnancy. In Perined, none of the neonatal herpes cases had a mother diagnosed with an active genital herpes infection during pregnancy. Preventive measures to reduce vertical herpes transmission (such as cesarean section) were less commonly reported by HCP in 2012-2015 compared with 2006-2011.

CONCLUSIONS

Neonatal herpes incidence in the Netherlands slowly increased over the last 15 years. An increased genital HSV prevalence during pregnancy or, to lower extent, the decreased guideline adherence by HCP may be responsible. A rise in asymptomatic maternal HSV shedding is also plausible, emphasizing the challenges in preventing neonatal herpes.

Vertikale Übertragung des Herpes-simplex-Virus: eine Aktualisierung

Infektionen mit den Herpes-simplex-Viren (HSV)-1 und -2 haben weltweit eine hohe Prävalenz. Eine HSV-Infektion während der Schwangerschaft kann eine neonatale Herpes-Infektion verursachen, die durch eine lebenslange Infektion mit Latenz- und Reaktivierungsperioden gekennzeichnet ist. Ein Säugling kann sich in utero (5 %), peripartal (85 %) oder postnatal (10 %) mit dem HS-Virus infizieren. Herpes neonatorum ist eine seltene aber bedeutsame Infektion, die mit schwerer Morbidität und Mortalität assoziiert sein kann, insbesondere bei Dissemination oder Beteiligung des zentralen Nervensystems. Fortschritte bei Diagnose und Therapie haben zur Verringerung der Mortalität sowie, in geringerem Ausmaß, zu einem verbesserten neurologischen Outcome geführt. Dennoch sind weitere Verbesserungen wünschenswert. Dabei ist es entscheidend, Ärzte in die Lage zu versetzen, diejenigen Säuglinge, die einem erhöhten Risiko einer HSV-Infektion ausgesetzt sind, zu erkennen und die Mutter-Kind-Übertragung effektiver zu verhindern. Ein lohnendes Ziel für die Zukunft ist die Entwicklung neuer antiviraler Wirkstoffe mit höherer Wirksamkeit.

Latent versus productive infection: the alpha herpesvirus switch

Alpha herpesviruses are common pathogens of mammals. They establish a productive infection in many cell types, but a life-long latent infection occurs in PNS neurons. A vast majority of the human population has latent HSV-1 infections. Currently, there is no cure to clear latent infections. Even though HSV-1 is among the best studied viral pathogens, regulation of latency and reactivation is not well understood due to several challenges including a lack of animal models that precisely recapitulate latency/reactivation episodes; a difficulty in modeling in vitro latency; and a limited understanding of neuronal biology. In this review, we discuss insights gained from in vitro latency models with a focus on the neuronal and viral factors that determine the mode of infection.

Vertical transmission of herpes simplex virus: an update

Herpes simplex virus (HSV)-1 and -2 infections are highly prevalent worldwide. HSV infection during pregnancy can result in neonatal herpes infection, which is characterized by lifelong infection with periods of latency and reactivation. HSV can be acquired by an infant during one of three periods: in utero (5 %), peripartum (85 %), or postnatal (10 %). Neonatal HSV is a rare but significant infection that may be associated with severe morbidity and mortality, especially if there is dissemination or central nervous system involvement. Diagnostic and therapeutic advances have led to a reduction in mortality and, to a lesser extent, improvement of neurodevelopmental outcomes, but further developments are still needed. It is essential to improve the clinician's ability to identify infants who are at increased risk of HSV infection and to prevent mother-to-child transmission. The development of novel antiviral agents with higher efficacy is a worthwhile aim for the future.

Vaccine-induced antibodies to herpes simplex virus glycoprotein D epitopes involved in virus entry and cell-to-cell spread correlate with protection against genital disease in guinea pigs

Herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) subunit antigen is included in many preclinical candidate vaccines. The rationale for including gD2 is to produce antibodies that block crucial gD2 epitopes involved in virus entry and cell-to-cell spread. HSV-2 gD2 was the only antigen in the Herpevac Trial for Women that protected against HSV-1 genital infection but not HSV-2. In that trial, a correlation was detected between gD2 ELISA titers and protection against HSV-1, supporting the importance of antibodies. A possible explanation for the lack of protection against HSV-2 was that HSV-2 neutralization titers were low, four-fold lower than to HSV-1. Here, we evaluated neutralization titers and epitope-specific antibody responses to crucial gD2 epitopes involved in virus entry and cell-to-cell spread as correlates of immune protection against genital lesions in immunized guinea pigs. We detected a strong correlation between neutralizing antibodies and protection against genital disease. We used a high throughput biosensor competition assay to measure epitope-specific responses to seven crucial gD2 linear and conformational epitopes involved in virus entry and spread. Some animals produced antibodies to most crucial epitopes while others produced antibodies to few. The number of epitopes recognized by guinea pig immune serum correlated with protection against genital lesions. We confirmed the importance of antibodies to each crucial epitope using monoclonal antibody passive transfer that improved survival and reduced genital disease in mice after HSV-2 genital challenge. We re-evaluated our prior study of epitope-specific antibody responses in women in the Herpevac Trial. Humans produced antibodies that blocked significantly fewer crucial gD2 epitopes than guinea pigs, and antibody responses in humans to some linear epitopes were virtually absent. Neutralizing antibody titers and epitope-specific antibody responses are important immune parameters to evaluate in future Phase I/II prophylactic human vaccine trials that contain gD2 antigen.

Review of mathematical models of HSV-2 vaccination: Implications for vaccine development

Development of a vaccine against herpes simplex virus type 2 (HSV-2), a life-long sexually-transmitted infection (STI), would be a major step forward in improving global sexual and reproductive health. In this review, we identified published literature of dynamic mathematical models assessing the impact of either prophylactic or therapeutic HSV-2 vaccination at the population level. We compared each study's model structure and assumptions as well as predicted vaccination impact. We examined possible causes of heterogeneity across model predictions, key gaps, and the implications of these findings for future modelling efforts. Only eight modelling studies have assessed the potential public health impact of HSV-2 vaccination, with the majority focusing on impact of prophylactic vaccines. The studies showed that even an imperfect prophylactic HSV-2 vaccine could have an important public health impact on HSV-2 incidence, and could also impact HIV indirectly in high HIV prevalence settings. Therapeutic vaccines also may provide public health benefits, though they have been explored less extensively. However, there was substantial variation in predicted population-level impact for both types of vaccine, reflecting differences in assumptions between model scenarios. Importantly, many models did not account for heterogeneity in infection rates such as by age, sex and sexual activity. Future modelling work to inform decisions on HSV vaccine development and implementation should consider cost-effectiveness, account for additional HSV-2 sequelae such as neonatal transmission, and model greater heterogeneity in infection rates between individuals, more realistic vaccine deployment, and more thorough sensitivity and uncertainty analyses.

Neonatal herpes simplex virus infections

Neonatal herpes simplex virus (HSV) is an uncommon but devastating infection in the newborn, associated with significant morbidity and mortality. The use of PCR for identification of infected infants and acyclovir for treatment has significantly improved the prognosis for affected infants. The subsequent use of suppressive therapy with oral acyclovir following completion of parenteral treatment of acute disease has further enhanced the long-term prognosis for these infants. This review article will discuss the epidemiology, risk factors and routes of acquisition, clinical presentation, and evaluation of an infant suspected to have the infection, and treatment of proven neonatal HSV disease.

Herpes simplex virus type 2 IgG antibodies in sera of umbilical cord as a proxy for placental infection in asymptomatic pregnant women

PROBLEM

Herpes simplex virus type 2 (HSV-2) infection is one of the most prevalent diseases worldwide and is mainly sexually transmitted. When infecting pregnant women, HSV-2 is able to infect the placenta, can reach the fetus, and may affect the fetal development. We sought to determine the prevalence of HSV-2 infection and reactivation in asymptomatic pregnant women, the correlation between IgG in the maternal circulation and cord blood, and the correlation between circulating IgG, placental, and newborn infection (blood cord).

METHOD OF STUDY

Serum samples and placental tissues from pregnant women and umbilical cord blood samples from their newborns were collected. Anti-HSV-2 antibodies were identified by ELISA, and HSV-2 DNA was detected by nested PCR.

RESULTS

The seropositivity of IgG in pregnant women was 29.7% and IgM was detected in 1 woman (0.5%). In the umbilical cord of newborns, 33.1% were IgG-positive and IgM was detected in 2 samples (1.5%). A positive correlation between HSV-2 IgG titers in serum from pregnant women and cord blood samples was found (r = .36, P = .001). A difference between the positive and negative placental groups (maternal side) was found in titers of IgG in sera of umbilical cord, which were significantly higher in the positive placental group (P = .004).

CONCLUSION

We describe for the first time that newborns from mothers with HSV-2 placental infection have higher IgG titers in sera of umbilical cord, suggesting IgGs antibodies can be indicative of placental viral infection in asymptomatic women.

Herpes Simplex Virus Infection in Infants Undergoing Meningitis Evaluation

BACKGROUND

Although neonatal herpes simplex virus (HSV) is a potentially devastating infection requiring prompt evaluation and treatment, large-scale assessments of the frequency in potentially infected infants have not been performed.

METHODS

We performed a retrospective cross-sectional study of infants ≤60 days old who had cerebrospinal fluid culture testing performed in 1 of 23 participating North American emergency departments. HSV infection was defined by a positive HSV polymerase chain reaction or viral culture. The primary outcome was the proportion of encounters in which HSV infection was identified. Secondary outcomes included frequency of central nervous system (CNS) and disseminated HSV, and HSV testing and treatment patterns.

RESULTS

Of 26 533 eligible encounters, 112 infants had HSV identified (0.42%, 95% confidence interval [CI]: 0.35%-0.51%). Of these, 90 (80.4%) occurred in weeks 1 to 4, 10 (8.9%) in weeks 5 to 6, and 12 (10.7%) in weeks 7 to 9. The median age of HSV-infected infants was 14 days (interquartile range: 9-24 days). HSV infection was more common in 0 to 28-day-old infants compared with 29- to 60-day-old infants (odds ratio 3.9; 95% CI: 2.4-6.2). Sixty-eight (0.26%, 95% CI: 0.21%-0.33%) had CNS or disseminated HSV. The proportion of infants tested for HSV (35%; range 14%-72%) and to whom acyclovir was administered (23%; range 4%-53%) varied widely across sites.

CONCLUSIONS

An HSV infection was uncommon in young infants evaluated for CNS infection, particularly in the second month of life. Evidence-based approaches to the evaluation for HSV in young infants are needed.

A combined carrier-adjuvant system of peptide nanofibers and toll-like receptor agonists potentiates robust CD8+ T cell responses

Improving CD8+ T cell responses activated by subunit vaccination is crucial for improving vaccine efficacy and safety. Here we report a carrier-adjuvant system composed of self-assembling peptide nanofibers presenting an immunodominant antigen from herpes simplex virus (HSV) and toll-like receptor (TLR) agonists that induces robust effector and memory CD8+ T cell responses in mice. The effector function of vaccine-induced CD8+ T cells was influenced by the type of TLR agonist. The use of CpG (TLR9 agonist) resulted in significantly greater specific in vivo cytotoxicity and trended towards more cells producing both IFN-γ and TNF-α compared to gardiquimod (TLR7 agonist). Prime-boost immunization with peptide nanofibers combined with either adjuvant resulted in development of HSV-specific CD8+ memory T cells further demonstrating the capability of the carrier-adjuvant system to induce strong HSV-specific CD8+ T cell responses. Inclusion of peptide epitope-nanofibers in protein-based subunit vaccines should increase the functional spectrum of the vaccine-elicited immune response and protection.

Meeting report: Initial World Health Organization consultation on herpes simplex virus (HSV) vaccine preferred product characteristics, March 2017

The development of vaccines against herpes simplex virus (HSV) is an important global goal for sexual and reproductive health. A key priority to advance development of HSV vaccines is the definition of preferred product characteristics (PPCs), which provide strategic guidance on World Health Organization (WHO) preferences for new vaccines, specifically from a low- and middle-income country (LMIC) perspective. To start the PPC process for HSV vaccines, the WHO convened a global stakeholder consultation in March 2017, to define the priority public health needs that should be addressed by HSV vaccines and discuss the key considerations for HSV vaccine PPCs, particularly for LMICs. Meeting participants outlined an initial set of overarching public health goals for HSV vaccines in LMICs, which are: to reduce the acquisition of HIV associated with HSV-2 infection in high HIV-prevalence populations and to reduce the burden of HSV-associated disease, including mortality and morbidity due to neonatal herpes and impacts on sexual and reproductive health. Participants also considered the role of prophylactic versus therapeutic vaccines, whether both HSV-2 and HSV-1 should be targeted, important target populations, and infection and disease endpoints for clinical trials. This article summarizes the main discussions from the consultation.

Chemical analysis and antiviral activity evaluation of Baccharis anomala

The chemical composition and antiviral activity of aqueous extract from Baccharis anomala was studied by bioactivity-guided fractionation. Ethanol precipitation and fractionation by molecular permeation allowed the separation of the anti-herpes simplex virus 1 (HSV-1) active fraction from aqueous extract (Fraction B). Natural Product Reagent A, FeCl₃ and thin-layer chromatography indicated the presence of phenolic compounds in the aqueous extract. Fraction B showed pronounced antiviral activity when tested with HSV-1 strains VR733/ATCC and Acyclovir-resistant 29-R, displaying virucidal but not virustatic activity.

Maternal Antiviral Immunoglobulin Accumulates in Neural Tissue of Neonates To Prevent HSV Neurological Disease

While antibody responses to neurovirulent pathogens are critical for clearance, the extent to which antibodies access the nervous system to ameliorate infection is poorly understood. In this study on herpes simplex virus 1 (HSV-1), we demonstrate that HSV-specific antibodies are present during HSV-1 latency in the nervous systems of both mice and humans. We show that antibody-secreting cells entered the trigeminal ganglion (TG), a key site of HSV infection, and persisted long after the establishment of latent infection. We also demonstrate the ability of passively administered IgG to enter the TG independently of infection, showing that the naive TG is accessible to antibodies. The translational implication of this finding is that human fetal neural tissue could contain HSV-specific maternally derived antibodies. Exploring this possibility, we observed HSV-specific IgG in HSV DNA-negative human fetal TG, suggesting passive transfer of maternal immunity into the prenatal nervous system. To further investigate the role of maternal antibodies in the neonatal nervous system, we established a murine model to demonstrate that maternal IgG can access and persist in neonatal TG. This maternal antibody not only prevented disseminated infection but also completely protected the neonate from neurological disease and death following HSV challenge. Maternal antibodies therefore have a potent protective role in the neonatal nervous system against HSV infection. These findings strongly support the concept that prevention of prenatal and neonatal neurotropic infections can be achieved through maternal immunization.

Herpes simplex virus 1 is a common infection of the nervous system that causes devastating neonatal disease. Using mouse and human tissue, we discovered that antiviral antibodies accumulate in neural tissue after HSV-1 infection in adults. Similarly, these antibodies pass to the offspring during pregnancy. We found that antiviral maternal antibodies can readily access neural tissue of the fetus and neonate. These maternal antibodies then protect neonatal mice against HSV-1 neurological infection and death. These results underscore the previously unappreciated role of maternal antibodies in protecting fetal and newborn nervous systems against infection. These data suggest that maternal immunization would be efficacious at preventing fetal/neonatal neurological infections.