Predictors of morbidity and mortality in neonates with herpes simplex virus infections. The National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group

Joint British Association for Sexual Health and HIV and Royal College of Obstetricians and Gynaecologists national UK guideline for the management of herpes simplex virus (HSV) in pregnancy and the neonate (2024 update)

This updated national UK guideline offers recommendations on the management of genital herpes simplex virus (HSV) in mothers and pregnant people during pregnancy and within 4 weeks following birth. It includes recommendations for first episode and recurrent HSV, HSV in preterm pre-labour rupture of membranes and in co-infection with HSV and HIV. Recommendations around management of the neonate are made, on prevention of postnatal transmission, management of breastfeeding, and the management of clinically discordant couples. This guideline is aimed at healthcare professionals working in sexual health clinics, maternity units, and those working on postnatal wards and neonatal units in the UK. However, the principles of the recommendations should be adopted across all services, including community care.

Improving antibody-mediated protection against HSV infection by eliminating interactions with the viral Fc receptor gE/gI

Herpes simplex virus (HSV) encodes surface glycoproteins that are host defense evasion molecules, allowing the virus to escape immune clearance. In addition to their role in neuropathogenesis and cell-cell spread, glycoproteins E and I (gE/gI) form a viral Fc receptor (vFcR) for most subclasses and allotypes of human IgG and promote evasion of humoral immune responses. While monoclonal antibodies (mAbs) protect mice from neonatal HSV (nHSV) infections, the impact of the vFcR on mAb-mediated protection by binding to IgG is unknown. Using HSV-1 with intact and ablated gE-mediated IgG Fc binding, and Fc-engineered antibodies with modified ability to interact with gE/gI, we investigated the role of the vFcR in viral pathogenesis and mAb-mediated protection from nHSV. The gD-specific human mAb HSV8 modified to lack binding to gE exhibited enhanced neutralization and in vivo protection compared to its native IgG1 form. This improved protection by the engineered mAbs was dependent on the presence of the vFcR. Human IgG3 allotypes lacking vFcR binding also exhibited enhanced antiviral activity in vivo, suggesting that vaccines that robustly induce IgG3 responses could show enhanced protection. suggesting the value of vaccination strategies that robustly induce this subclass. Lastly, analysis of longitudinal responses to acute primary genital infection in humans raised the possibility that unlike most viruses, HSV may exhibited slow induction of IgG3. In summary, this study demonstrates that mAbs lacking the ability to interact with the vFcR can exhibit improved protection from HSV-offering new prospects for antibody-based interventions.

Epidemiology and treatment of herpes simplex virus in the neonatal intensive care unit

OBJECTIVE

Describe the epidemiology and clinical characteristics of infants in the neonatal intensive care unit (NICU) with acyclovir exposure and herpes simplex virus (HSV) infection.

STUDY DESIGN

Our primary analysis was to evaluate the prevalence of HSV infection among infants in the NICU who received acyclovir. We compared characteristics of infants with and without HSV and used multivariable regression analyses to assess associations between infection and clinical outcomes.

RESULT

Of 1,057,061 infants, 17,910 (2%) received acyclovir. Of those who received acyclovir, 1090 (5%) had HSV. Infection was associated with lower gestational age and lower birth weight. Multivariable models demonstrated that infected infants had higher mortality, greater postmenstrual age at discharge, and longer length of stay.

CONCLUSION

Infants in the NICU who received acyclovir and have HSV are more likely to be born at lower gestational age, have lower birth weight, and have higher morbidities and mortality.

Neonatal herpes: case series in two obstetric centres over a 10-year period (2013-2023), France

Neonatal herpes simplex virus (HSV) infection (HSV infection in infants less than 6 weeks of age) is rare but mortality and morbidity rates are high after disseminated disease and encephalitis. In France, the epidemiology is poorly described, and two decades ago, incidence was estimated to be 3 per 100,000 live births a year. We describe determinants, epidemiologic and clinical characteristics of neonatal HSV infection in a managed-care population attending in two major obstetric and paediatric centres, Paris, France, over a 10-year period. This retrospective case series study was conducted from 2013 to 2023, in infants less than 42 days of age who had virologically confirmed HSV infection. We report an overall rate of neonatal herpes of 5.5 per 100,000 live births a year and an incidence of symptomatic cases of 1.2 per 100,000 live births a year. HSV-1 was the major serotype involved (84.2%) and post-natal acquisition through the orolabial route reached 63.2%. All neonates who had neonatal HSV PCR screening (owing to clinical signs in parents) and who received prompt acyclovir treatment remained asymptomatic. Symptomatic forms accounted for 21.1% cases of the total and mortality was high (62.5% of symptomatic forms).   Conclusion: This case series confirms that neonates at risk for HSV disease and poor outcome are those born to HSV-seronegative mothers, preterm infants, and those who received acyclovir after onset of symptoms (mainly because mothers did not present evidence of acute HSV infection). Our study confirms the major role of HSV-1 and the frequency of its early post-natal acquisition. What is known: • Neonatal herpes simplex virus infection is rare but motality and morbidity rates are high after disseminted disease and encephalitis. National recommendations exist worldwide but mangement of this disease is not always easy. What is new: • As in France epidemiology of neonatal herpes is poorly described, our report is potentially an important addition to the existing literature. Moreover, we describe local practice that may be useful to physicians.

Viral-induced inflammation can lead to adverse pregnancy outcomes

INTRODUCTION

Parvoviruses are DNA viruses of small size. There have been a number of reports indicating the possible effects of B19 infections during pregnancy. These effects include spontaneous abortions, stillbirth, fetal damage, and quite often, fetal anemia with hydrops fetalis.

Clinical Review of Risk of Nephrotoxicity with Acyclovir Use for Treatment of Herpes Simplex Virus Infections in Neonates and Children

OBJECTIVE

This study aims to clarify the risk of nephrotoxicity with intravenous use of acyclovir (ACV) for the treatment of neonates (ages <3 months) and children (ages ≥3 months to <12 years) with herpes simplex virus (HSV) infections and to identify gaps in knowledge that could be further investigated.

METHODS

Multiple databases were searched to identify studies on risk of nephrotoxicity with ACV use for treatment of invasive HSV infections, defined as any neonatal infection or HSV encephalitis (HSE) in children.

RESULTS

There were 5 and 14 studies that evaluated the risk of ACV-associated nephrotoxicity in neonates and children, respectively. The US Food and Drug Administration (FDA) delayed the approval of high (HD; 60 mg/kg/day) ACV in neonates secondary to risk of toxicity. Based on our review, the risk of ACV-associated nephrotoxicity was lower in the neonatal compared with the pediatric population. Acyclovir dose >1500 mg/m2, older age, and concomitant use of nephrotoxic drugs were identified as variables that increased the risk of ACV nephrotoxicity in children. Although the FDA has approved the use of HD ACV for the treatment of HSE in children, the American Academy of Pediatrics recommends a lower dose to minimize the risk of toxicity. The efficacy and safety of high vs lower doses of ACV for the management of HSE in children has yet to be evaluated.

CONCLUSIONS

The risk of ACV-associated nephrotoxicity was lower among neonates compared with older children. Future studies are needed to identify the optimal dosage that minimizes toxicities and maximizes the efficacy of ACV in children with HSE.

Beyond TORCH: A narrative review of the impact of antenatal and perinatal infections on the risk of disability

Infections and inflammation during pregnancy or early life can alter child neurodevelopment and increase the risk for structural brain abnormalities and mental health disorders. There is strong evidence that TORCH infections (i.e., Treponema pallidum, Toxoplasma gondii, rubella virus, cytomegalovirus, herpes virus) alter fetal neurodevelopment across multiple developmental domains and contribute to motor and cognitive disabilities. However, the impact of a broader range of viral and bacterial infections on fetal development and disability is less well understood. We performed a literature review of human studies to identify gaps in the link between maternal infections, inflammation, and several neurodevelopmental domains. We found strong and moderate evidence respectively for a higher risk of motor and cognitive delays and disabilities in offspring exposed to a range of non-TORCH pathogens during fetal life. In contrast, there is little evidence for an increased risk of language and sensory disabilities. While guidelines for TORCH infection prevention during pregnancy are common, further consideration for prevention of non-TORCH infections during pregnancy for fetal neuroprotection may be warranted.

Boosting of vaginal HSV-2-specific B and T cell responses by intravaginal therapeutic immunization results in diminished recurrent HSV-2 disease

Boosting herpes simplex virus (HSV)-specific immunity in the genital tissues of HSV-positive individuals to increase control of HSV-2 recurrent disease and virus shedding is an important goal of therapeutic immunization and would impact HSV-2 transmission. Experimental therapeutic HSV-2 vaccines delivered by a parenteral route have resulted in decreased recurrent disease in experimental animals. We used a guinea pig model of HSV-2 infection to test if HSV-specific antibody and cell-mediated responses in the vaginal mucosa would be more effectively increased by intravaginal (Ivag) therapeutic immunization compared to parenteral immunization. Therapeutic immunization with HSV glycoproteins and CpG adjuvant increased glycoprotein-specific IgG titers in vaginal secretions and serum to comparable levels in Ivag- and intramuscular (IM)-immunized animals. However, the mean numbers of HSV glycoprotein-specific antibody secreting cells (ASCs) and IFN-γ SCs were greater in Ivag-immunized animals demonstrating superior boosting of immunity in the vaginal mucosa compared to parenteral immunization. Therapeutic Ivag immunization also resulted in a significant decrease in the cumulative mean lesion days compared to IM immunization. There was no difference in the incidence or magnitude of HSV-2 shedding in either therapeutic immunization group compared to control-treated animals. Collectively, these data demonstrated that Ivag therapeutic immunization was superior compared to parenteral immunization to boost HSV-2 antigen-specific ASC and IFN-γ SC responses in the vagina and control recurrent HSV-2 disease. These results suggest that novel antigen delivery methods providing controlled release of optimized antigen/adjuvant combinations in the vaginal mucosa would be an effective approach for therapeutic HSV vaccines. IMPORTANCE HSV-2 replicates in skin cells before it infects sensory nerve cells where it establishes a lifelong but mostly silent infection. HSV-2 occasionally reactivates, producing new virus which is released back at the skin surface and may be transmitted to new individuals. Some HSV-specific immune cells reside at the skin site of the HSV-2 infection that can quickly activate and clear new virus. Immunizing people already infected with HSV-2 to boost their skin-resident immune cells and rapidly control the new HSV-2 infection is logical, but we do not know the best way to administer the vaccine to achieve this goal. In this study, a therapeutic vaccine given intravaginally resulted in significantly better protection against HSV-2 disease than immunization with the same vaccine by a conventional route. Immunization by the intravaginal route resulted in greater stimulation of vaginal-resident, virus-specific cells that produced antibody and produced immune molecules to rapidly clear virus.

Antibody effector functions are required for broad and potent protection of neonates from herpes simplex virus infection

The failure of multiple herpes simplex virus (HSV) vaccine candidates that induce neutralizing antibody responses raises the hypothesis that other activities, such as Fc domain-dependent effector functions, may be critical for protection. While neonatal HSV (nHSV) infection result in mortality and lifelong neurological morbidity in humans, it is uncommon among neonates with a seropositive birthing parent, suggesting the potential efficacy of antibody-based therapeutics to protect neonates. We therefore investigated the mechanisms of monoclonal antibody (mAb)-mediated protection in a mouse model of nHSV infection. Both neutralization and effector functions contributed to robust protection against nHSV-1. In contrast, effector functions alone were sufficient to protect against nHSV-2, exposing a functional dichotomy between virus types that is consistent with vaccine trial results. Together, these results emphasize that effector functions are crucial for optimal mAb-mediated protection, informing effective Ab and vaccine design, and demonstrating the potential of polyfunctional Abs as potent therapeutics for nHSV infections.

Neonatal herpes simplex presenting as a zosteriform eruption

Herpes simplex virus (HSV) infection in newborn infants is a potentially devastating disease leading to death and disability. Skin, eye and mouth (SEM) infections account for approximately half of the cases in the USA. The appearance of skin findings often guides clinicians towards early diagnosis of HSV infection, prompt interventions and life-saving management; however, less than half of neonates with proven disease present with characteristic vesicular lesions. Furthermore, if SEM infections are not treated promptly, there is significant risk of progression to central nervous system and disseminated disease. We present a case of HSV-2 infection in a neonate with an atypical zosteriform eruption on day 3 of life. This case demonstrates that neonatal HSV can unusually present in a zosteriform rash. By elucidating this unique presentation, we highlight atypical HSV skin presentation and emphasise on the importance of earlier diagnosis and antiviral treatment to prevent the associated morbidity and mortality.

Real-World Data on Cutaneous Recurrences Following Neonatal Herpes Simplex Virus Disease

Though primarily used to improve neurodevelopmental outcomes, suppressive oral acyclovir therapy following neonatal herpes simplex virus disease also decreases cutaneous recurrences. Skin recurrences can still occur, however, and understanding their frequency is helpful in managing patients with this rare disease.

Maternally transferred mAbs protect neonatal mice from HSV-induced mortality and morbidity

Neonatal herpes simplex virus (nHSV) infections often result in significant mortality and neurological morbidity despite antiviral drug therapy. Maternally transferred herpes simplex virus (HSV)-specific antibodies reduce the risk of clinically overt nHSV, but this observation has not been translationally applied. Using a neonatal mouse model, we tested the hypothesis that passive transfer of HSV-specific human mAbs can prevent mortality and morbidity associated with nHSV. The mAbs were expressed in vivo via vectored immunoprophylaxis or recombinantly. Through these maternally derived routes or through direct administration to pups, diverse mAbs to HSV glycoprotein D protected against neonatal HSV-1 and HSV-2 infection. Using in vivo bioluminescent imaging, both pre- and post-exposure mAb treatment significantly reduced viral load in mouse pups. Together these studies support the notion that HSV-specific mAb-based therapies could prevent or improve HSV infection outcomes in neonates.

Neonatal Herpes Simplex Virus: Cutaneous Recurrence Is Common on Stopping Prophylactic Suppression Therapy

Neonatal herpes simplex virus (HSV) infection is a potentially devastating disease. Data on the recurrence of disease while on suppressive therapy are limited. We reviewed cases of neonatal HSV. Prematurity was associated with more recurrence. No systemic or CNS recurrence occurred, but there were frequent recurrences of skin lesions.

The Impaired Neurodevelopment of Human Neural Rosettes in HSV-1-Infected Early Brain Organoids

Intrauterine infections during pregnancy by herpes simplex virus (HSV) can cause significant neurodevelopmental deficits in the unborn/newborn, but clinical studies of pathogenesis are challenging, and while animal models can model some aspects of disease, in vitro studies of human neural cells provide a critical platform for more mechanistic studies. We utilized a reductionist approach to model neurodevelopmental outcomes of HSV-1 infection of neural rosettes, which represent the in vitro equivalent of differentiating neural tubes. Specifically, we employed early-stage brain organoids (ES-organoids) composed of human induced pluripotent stem cells (hiPSCs)-derived neural rosettes to investigate aspects of the potential neuropathological effects induced by the HSV-1 infections on neurodevelopment. To allow for the long-term differentiation of ES-organoids, viral infections were performed in the presence of the antiviral drug acyclovir (ACV). Despite the antiviral treatment, HSV-1 infection caused organizational changes in neural rosettes, loss of structural integrity of infected ES-organoids, and neuronal alterations. The inability of ACV to prevent neurodegeneration was associated with the generation of ACV-resistant mutants during the interaction of HSV-1 with differentiating neural precursor cells (NPCs). This study models the effects of HSV-1 infection on the neuronal differentiation of NPCs and suggests that this environment may allow for accelerated development of ACV-resistance.

Herpes Simplex Virus-2 Variation Contributes to Neurovirulence During Neonatal Infection

Herpes simplex virus (HSV) infection of the neonatal brain causes severe encephalitis and permanent neurologic deficits. However, infants infected with HSV at the time of birth follow varied clinical courses, with approximately half of infants experiencing only external infection of the skin rather than invasive neurologic disease. Understanding the cause of these divergent outcomes is essential to developing neuroprotective strategies. To directly assess the contribution of viral variation to neurovirulence, independent of human host factors, we evaluated clinical HSV isolates from neonates with different neurologic outcomes in neurologically relevant in vitro and in vivo models. We found that isolates taken from neonates with encephalitis are more neurovirulent in human neuronal culture and mouse models of HSV encephalitis, as compared to isolates collected from neonates with skin-limited disease. These findings suggest that inherent characteristics of the infecting HSV strain contribute to disease outcome following neonatal infection.

Monoclonal antibody therapy of herpes simplex virus: An opportunity to decrease congenital and perinatal infections

The fetal/neonatal period represents both a unique window of opportunity for interventions as well as vulnerability to a number of viral infections. While Herpesviruses such as herpes simplex virus (HSV) are highly prevalent and typically of little consequence among healthy adults, they are among the most consequential infections of early life. Despite treatment with antiviral drugs, neonatal HSV (nHSV) infections can still result in significant mortality and lifelong neurological morbidity. Fortunately, newborns in our pathogen-rich world inherit some of the protection provided by the maternal immune system in the form of transferred antibodies. Maternal seropositivity, resulting in placental transfer of antibodies capable of neutralizing virus and eliciting the diverse effector functions of the innate immune system are associated with dramatically decreased risk of nHSV. Given this clear epidemiological evidence of reduced risk of infection and its sequelae, we present what is known about the ability of monoclonal antibody therapies to treat or prevent HSV infection and explore how effective antibody-based interventions in conjunction with antiviral therapy might reduce early life mortality and long-term morbidity.

Herpes Simplex Virus Seroprevalence among Pregnant Finnish Women and Their Spouses-A Six-Year Follow-Up Cohort Study

The aim was to evaluate the herpes simplex virus (HSV) seroprevalence and seroconversion among 285 pregnant women and their 120 male spouses in Finland during a six-year follow-up (FU) between 1998–2008. We also studied the effect of sexual habits, pregnancy, and other demographic factors on the acquisition of HSV infection. Combined HSV-1 and HSV-2-IgG antibodies were assessed in the first baseline serum samples with an indirect enzyme immunoassay method. The individuals with seronegative or borderline HSV serology at baseline were additionally tested using their latest FU serum sample available. The overall HSV seroprevalence during the FU was 58.9% (168/285) among the women and 53.3% (64/120) among their spouses. The seroconversion rate was 11.4% (15/132) and 12.5% (8/64) among women and their spouses, respectively. Both spouses were HSV seropositive in 39.2% (47/120). To determine the HSV-2 seroprevalence, we also tested all HSV-seropositive participants using HSV-2-specific antigen. HSV-2 seropositivity was detected in 10.9% (44/405) of the participants. The age (p = 0.006) and history of genital warts (p = 0.006) of the women were associated with combined HSV-1 and/or HSV-2 seropositivity, while a younger age was related to HSV seroconversion (p = 0.023). Among the male spouses, HSV seropositivity was associated with the practice of oral sex (p = 0.033). To conclude, women of childbearing age acquire primary HSV infections and the presence of HSV in oral epithelium is common among HSV-seropositive individuals.

An mRNA vaccine to prevent genital herpes

The rapid development of two nucleoside-modified mRNA vaccines that are safe and highly effective against coronavirus disease 2019 has transformed the vaccine field. The mRNA technology has the advantage of accelerated immunogen discovery, induction of robust immune responses, and rapid scale up of manufacturing. Efforts to develop genital herpes vaccines have been ongoing for 8 decades without success. The advent of mRNA technology has the potential to change that narrative. Developing a genital herpes vaccine is a high public health priority. A prophylactic genital herpes vaccine should prevent HSV-1 and HSV-2 genital lesions and infection of dorsal root ganglia, the site of latency. Vaccine immunity should be durable for decades, perhaps with the assistance of booster doses. While these goals have been elusive, new efforts with nucleoside-modified mRNA-lipid nanoparticle vaccines show great promise. We review past approaches to vaccine development that were unsuccessful or partially successful in large phase 3 trials, and describe lessons learned from these trials. We discuss our trivalent mRNA-lipid nanoparticle approach for a prophylactic genital herpes vaccine and the ability of the vaccine to induce higher titers of neutralizing antibodies and more durable CD4+ T follicular helper cell and memory B cell responses than protein-adjuvanted vaccines.

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.

Pathogenesis and virulence of herpes simplex virus

Two of the most prevalent human viruses worldwide, herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2, respectively), cause a variety of diseases, including cold sores, genital herpes, herpes stromal keratitis, meningitis and encephalitis. The intrinsic, innate and adaptive immune responses are key to control HSV, and the virus has developed mechanisms to evade them. The immune response can also contribute to pathogenesis, as observed in stromal keratitis and encephalitis. The fact that certain individuals are more prone than others to suffer severe disease upon HSV infection can be partially explained by the existence of genetic polymorphisms in humans. Like all herpesviruses, HSV has two replication cycles: lytic and latent. During lytic replication HSV produces infectious viral particles to infect other cells and organisms, while during latency there is limited gene expression and lack of infectious virus particles. HSV establishes latency in neurons and can cause disease both during primary infection and upon reactivation. The mechanisms leading to latency and reactivation and which are the viral and host factors controlling these processes are not completely understood. Here we review the HSV life cycle, the interaction of HSV with the immune system and three of the best-studied pathologies: Herpes stromal keratitis, herpes simplex encephalitis and genital herpes. We also discuss the potential association between HSV-1 infection and Alzheimer's disease.

The Hippocampal Vulnerability to Herpes Simplex Virus Type I Infection: Relevance to Alzheimer's Disease and Memory Impairment

Herpes simplex virus type 1 (HSV-1) as a possible infectious etiology in Alzheimer’s disease (AD) has been proposed since the 1980s. The accumulating research thus far continues to support the association and a possible causal role of HSV-1 in the development of AD. HSV-1 has been shown to induce neuropathological and behavioral changes of AD, such as amyloid-beta accumulation, tau hyperphosphorylation, as well as memory and learning impairments in experimental settings. However, a neuroanatomical standpoint of HSV-1 tropism in the brain has not been emphasized in detail. In this review, we propose that the hippocampal vulnerability to HSV-1 infection plays a part in the development of AD and amnestic mild cognitive impairment (aMCI). Henceforth, this review draws on human studies to bridge HSV-1 to hippocampal-related brain disorders, namely AD and aMCI/MCI. Next, experimental models and clinical observations supporting the neurotropism or predilection of HSV-1 to infect the hippocampus are examined. Following this, factors and mechanisms predisposing the hippocampus to HSV-1 infection are discussed. In brief, the hippocampus has high levels of viral cellular receptors, neural stem or progenitor cells (NSCs/NPCs), glucocorticoid receptors (GRs) and amyloid precursor protein (APP) that support HSV-1 infectivity, as well as inadequate antiviral immunity against HSV-1. Currently, the established diseases HSV-1 causes are mucocutaneous lesions and encephalitis; however, this review revises that HSV-1 may also induce and/or contribute to hippocampal-related brain disorders, especially AD and aMCI/MCI.

Variation in Diagnostic Testing and Empiric Acyclovir Use for HSV Infection in Febrile Infants

BACKGROUND AND OBJECTIVES

Clinicians evaluating for herpes simplex virus (HSV) in febrile infants must balance detection with overtesting, and there is no universally accepted approach to risk stratification. We aimed to describe variation in diagnostic evaluation and empirical acyclovir treatment of infants aged 0 to 60 days presenting with fever and determine the association between testing and length of stay (LOS).

METHODS

In this retrospective 44-hospital observational study, we used the Pediatric Health Information System database to identify infants aged ≤60 days evaluated for fever in emergency departments from January 2016 through December 2017. We described hospital-level variation in laboratory testing, including HSV, imaging and other diagnostic evaluations, acyclovir use, and LOS. We assessed the relationship between HSV testing and LOS using generalized linear mixed effects models adjusted for age and illness severity.

RESULTS

In 24 535 encounters for fever, the median HSV testing frequency across hospitals was 35.6% (interquartile range [IQR]: 28.5%-53.5%) for infants aged 0 to 21 days and 12% (IQR: 8.6%-15.7%) for infants aged 22 to 60 days. Among HSV-tested patients, median acyclovir use across hospitals was 79.2% (IQR: 68.1%-89.7%) for those aged 0 to 21 days and 63.6% (IQR: 44.1%-73%) for those aged 22 to 60 days. The prevalence of additional testing varied substantially by hospital and age group. Risk-adjusted LOS for HSV-tested infants was significantly longer than risk-adjusted LOS for those not tested (2.6 vs 1.9 days, P < .001).

CONCLUSIONS

Substantial variation exists in diagnostic evaluation and acyclovir use, and infants who received HSV testing had a longer LOS than infants who did not. This variability supports the need for further studies to help clinicians better risk-stratify febrile infants and to guide HSV testing and treatment decisions.

Evaluation of suspected neonatal herpes simplex virus infection in preterm versus term newborns in the neonatal intensive care unit

BACKGROUND

While national guidelines are available for the evaluation and management of term infants at risk for herpes simplex virus (HSV) infection, such guidelines are lacking for preterm infants. We sought to determine the risk factors and clinical characteristics of preterm vs. term infants who were evaluated and treated empirically for HSV infection in the neonatal intensive care unit (NICU).

METHODS

In a retrospective cohort study, medical records of all infants who were admitted to our NICU (2009-2016) and who were evaluated and empirically treated for HSV were reviewed for mothers' and infants' demographics, clinical characteristics, and laboratory findings.

RESULTS

During the study period 4.2% (103/2,471) of all preterm infants, and 6.0% (112/1,865) of all term infants were evaluated and treated empirically for neonatal HSV. Among all infants who were evaluated and treated for HSV, 5.5% (12/215) had neonatal HSV disease, of whom 83.3% (10/12) were preterm infants. In comparison to term, preterm infants were more likely to be evaluated and treated, if they had a maternal history of HSV [OR 2.51 (95% CI: 1.41-4.48)], prolonged rupture of membranes [2.64 (1.221-5.73)], leukopenia [3.65 (1.94-6.87)] and thrombocytopenia [2.25 (0.85-5.89)]. HSV disease was associated with a higher mortality compared to those without disease [25% (3/12) vs. 4.4% (9/203) respectively; p = <0.05].

CONCLUSION

Preterm infants evaluated and empirically treated for HSV have a higher burden of HSV infection than term infants. HSV should be considered in the management of preterm infant with a maternal history of HSV, prolonged rupture of membranes, and thrombocytopenia.

Heterogeneous cutaneous findings associated with intrauterine HSV infection: A case series and literature review

BACKGROUND/OBJECTIVE

Herpes simplex virus (HSV) infection acquired in utero may present with non-vesicular dermatologic findings in affected newborns, which may pose a diagnostic dilemma. We aimed to describe and assess the range of non-vesiculobullous skin lesions that neonates with intrauterine HSV infection may manifest at birth.

METHODS

We collected a multicenter case series and conducted a literature review of neonates with intrauterine HSV infection presenting with non-vesiculobullous cutaneous lesions.

RESULTS

Twenty-two cases were reviewed, including six managed clinically by members of our team and 16 identified in the literature. Four (18%) were associated with twin pregnancies, and thirteen (59%) cases occurred in premature infants. Only four (18%) mothers had a documented history of HSV infection. Twelve (55%) cases resulted in poor outcomes, including long-term neurologic sequelae or death. Cutaneous manifestations included erosions, ulcerations, crusted papules or plaques, calcinosis cutis, excoriations, macules (erythematous, hypopigmented, or hyperpigmented), cutaneous atrophy, contractures, and bruising. About one-third of neonates developed new-onset vesicular lesions within a week of birth; in each of these cases, accurate diagnosis and therapy were delayed until appearance of vesicles.

CONCLUSIONS

The range of dermatologic findings associated with intrauterine HSV is extremely broad, and the various morphologies present at birth likely reflect different stages of the ongoing evolution of an HSV infection that began in utero. Clinicians should have a low threshold for HSV testing in premature neonates born with atypical cutaneous lesions, since early detection and treatment of HSV may reduce morbidity and mortality from systemic complications.

Case Report: Rapid Recognition and Immune Modulation of Secondary HLH Due to Disseminated HSV Infection

We describe the case of a newborn who presented with multiple organ dysfunction syndrome (MODS) and hyperferritinemia, who eventually met criteria for hemophagocytic lymphohistiocytosis (HLH) due to disseminated herpes simplex virus 1 (HSV-1). While the cytokine storm abated after administration of multiple immune modulatory therapies including dexamethasone, etoposide, intravenous immune globulin, anakinra, as well as the interferon gamma antagonist emapalumab, multiple organ dysfunction syndrome progressed. Care was withdrawn after 5 days. Subsequent genetic testing did not reveal any mutations associated with familial HLH. This case highlights that even with appropriate antiviral treatment and immune suppression, disseminated HSV is often fatal. Further study is warranted to determine whether early immune modulatory therapy including interferon gamma blockade can interrupt the HLH inflammatory cascade and prevent progression of MODS.

Role of Inflammation in Virus Pathogenesis during Pregnancy

Viral infections during pregnancy lead to a spectrum of maternal and fetal outcomes, ranging from asymptomatic disease to more critical conditions presenting with severe maternal morbidity, stillbirth, preterm birth, intrauterine growth restriction, and fetal congenital anomalies, either apparent at birth or later in life. In this article, we review the pathogenesis of several viral infections that are particularly relevant in the context of pregnancy and intrauterine inflammation. Understanding the diverse mechanisms employed by viral pathogens as well as the repertoire of immune responses induced in the mother may help to establish novel therapeutic options to attenuate changes in the maternal-fetal interface and prevent adverse pregnancy outcomes.

Vaccines for Perinatal and Congenital Infections-How Close Are We?

Congenital and perinatal infections are transmitted from mother to infant during pregnancy across the placenta or during delivery. These infections not only cause pregnancy complications and still birth, but also result in an array of pediatric morbidities caused by physical deformities, neurodevelopmental delays, and impaired vision, mobility and hearing. Due to the burden of these conditions, congenital and perinatal infections may result in lifelong disability and profoundly impact an individual's ability to live to their fullest capacity. While there are vaccines to prevent congenital and perinatal rubella, varicella, and hepatitis B infections, many more are currently in development at various stages of progress. The spectrum of our efforts to understand and address these infections includes observational studies of natural history of disease, epidemiological evaluation of risk factors, immunogen design, preclinical research of protective immunity in animal models, and evaluation of promising candidates in vaccine trials. In this review we summarize this progress in vaccine development research for Cytomegalovirus, Group B Streptococcus, Herpes simplex virus, Human Immunodeficiency Virus, Toxoplasma, Syphilis, and Zika virus congenital and perinatal infections. We then synthesize this evidence to examine how close we are to developing a vaccine for these infections, and highlight areas where research is still needed.

Protection against herpes simplex virus type 2 infection in a neonatal murine model using a trivalent nucleoside-modified mRNA in lipid nanoparticle vaccine

Neonatal herpes is a dreaded complication of genital herpes infection in pregnancy. We recently compared two vaccine platforms for preventing genital herpes in female mice and guinea pigs and determined that HSV-2 glycoproteins C, D and E expressed using nucleoside-modified mRNA in lipid nanoparticles provided better protection than the same antigens produced as baculovirus proteins and administered with CpG and alum. Here we evaluated mRNA and protein immunization for protection against neonatal herpes. Female mice were immunized prior to mating and newborns were infected intranasally with HSV-2. IgG binding and neutralizing antibody levels in mothers and newborns were comparable using the mRNA or protein vaccines. Both vaccines protected first and second litter newborns against disseminated infection based on virus titers in multiple organs. We conclude that both vaccines are efficacious at preventing neonatal herpes, which leaves the mRNA vaccine as our preferred candidate based on better protection against 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.

Trivalent Glycoprotein Subunit Vaccine Prevents Neonatal Herpes Simplex Virus Mortality and Morbidity

Herpes simplex virus (HSV) can cause severe infection in neonates leading to mortality and lifelong morbidity. Prophylactic approaches, such as maternal immunization, could prevent neonatal HSV (nHSV) infection by providing protective immunity and preventing perinatal transmission. We previously showed that maternal immunization with a replication-defective HSV vaccine candidate, dl5-29, leads to transfer of virus-specific antibodies into the neonatal circulation and protects against nHSV neurological sequela and mortality (C. D. Patel, I. M. Backes, S. A. Taylor, Y. Jiang, et al., Sci Transl Med, 11:eaau6039, 2019, https://doi.org/10.1126/scitranslmed.aau6039). In this study, we evaluated the efficacy of maternal immunization with an experimental trivalent (gC2, gD2, and gE2) subunit vaccine to protect against nHSV. Using a murine model of nHSV, we demonstrated that maternal immunization with the trivalent vaccine protected offspring against nHSV-disseminated disease and mortality. In addition, offspring of immunized dams were substantially protected from behavioral pathology following HSV infection. This study supports the idea that maternal immunization is a viable strategy for the prevention of neonatal infections.IMPORTANCE Herpes simplex virus is among the most serious infections of newborns. Current antiviral therapies can prevent mortality if infection is recognized early and treated promptly. Most children who survive nHSV develop lifelong neurological and behavioral deficits, despite aggressive antiviral treatment. We propose that maternal immunization could provide protection against HSV for both mother and baby. To this end, we used a trivalent glycoprotein vaccine candidate to demonstrate that offspring are protected from nHSV following maternal immunization. Significantly, this approach protected offspring from long-term behavioral morbidity. Our results emphasize the importance of providing protective immunity to neonates during this window of vulnerability.

Diagnosis and Management of Neonatal Herpes Simplex Infection in the Emergency Department

Neonatal herpes simplex virus infection (HSV) is rare in neonates, with an estimated global incidence of 10 per 100,000 live births. Neonatal HSV is challenging to diagnose due to often vague signs and symptoms. Untreated, the mortality of some HSV subtypes exceeds 80%. Overtesting and overtreatment can result in prolonged hospitalizations and expose neonates to medication toxicity. In contrast, prompt evaluation and use of empiric antiviral therapy before the results of definitive testing can improve outcomes for infants with HSV. A wide degree of practice variation exists with respect to testing and treatment for neonatal HSV, and more research is required to safely risk-stratify this population. This review presents the epidemiology, risk factors, presenting features, and emergency department management of neonatal HSV infection.

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.

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.

Manifestations of Herpes Virus Infections in the Nervous System

The 3 neurotropic human herpes viruses, herpes simplex virus (HSV) type 1 and 2, and varicella-zoster virus (VZV) are capable of establishment of latent viral infection in trigeminal and dorsal root ganglia. HSV-1, and more rarely HSV-2, carries the potential to cause meningoencephalitis, with devastating clinical consequences. Immediate diagnosis, based on clinical presentation, MRI imaging, and molecular diagnosis by polymerase chain reaction, and initiation of therapy are mandatory to reduce mortality and neurologic permanent sequelae. VZV is associated with postprimary infection and reactivation disorders that may affect anywhere in the neuraxis. Early diagnosis and therapy are required.

Laboratory Diagnosis of Neonatal Herpes Simplex Virus Infections

Herpes simplex virus (HSV) is a common and often benign infection in humans; although it less commonly affects newborns, infection in this age group can be devastating. Newborns often present with nonspecific clinical findings, making timely and accurate diagnosis of infection critical. A wide variety of tests are available for detecting herpes simplex virus infection, but only a subset are useful and validated in the newborn population. The current review summarizes available diagnostic testing for neonatal disease, including discussing limitations, unmet needs, and emerging data on molecular testing methods.

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.

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.

Increased Frequency of Virus Shedding by Herpes Simplex Virus 2-Infected Guinea Pigs in the Absence of CD4+ T Lymphocytes

Reactivation of herpes simplex virus 2 (HSV-2) results in infection of epithelial cells at the neuro-epithelial junction and shedding of virus at the epithelial surface. Virus shedding can occur in either the presence or absence of clinical disease and is usually of short duration, although the shedding frequency varies among individuals. The basis for host control of virus shedding is not well understood, although adaptive immune mechanisms are thought to play a central role. To determine the importance of CD4⁺ T cells in control of HSV-2 shedding, this subset of immune cells was depleted from HSV-2-infected guinea pigs by injection of an anti-CD4 monoclonal antibody (MAb). Guinea pigs were treated with the depleting MAb after establishment of a latent infection, and vaginal swabs were taken daily to monitor shedding by quantitative PCR. The cumulative number of HSV-2 shedding days and the mean number of days virus was shed were significantly increased in CD4-depleted compared to control-treated animals. However, there was no difference in the incidence of recurrent disease between the two treatment groups. Serum antibody levels and the number of HSV-specific antibody-secreting cells in secondary lymphoid tissues were unaffected by depletion of CD4⁺ T cells; however, the frequency of functional HSV-specific, CD8⁺ gamma interferon-secreting cells was significantly decreased. Together, these results demonstrate an important role for CD4⁺ T lymphocytes in control of virus shedding that may be mediated in part by maintenance of HSV-specific CD8⁺ T cell populations. These results have important implications for development of therapeutic vaccines designed to control HSV-2 shedding.IMPORTANCE Sexual transmission of HSV-2 results from viral shedding following reactivation from latency. The immune cell populations and mechanisms that control HSV-2 shedding are not well understood. This study examined the role of CD4⁺ T cells in control of virus shedding using a guinea pig model of genital HSV-2 infection that recapitulates the shedding of virus experienced by humans. We found that the frequency of virus-shedding episodes, but not the incidence of clinical disease, was increased by depletion of CD4⁺ T cells. The HSV-specific antibody response was not diminished, but frequency of functional HSV-reactive CD8⁺ T cells was significantly diminished by CD4 depletion. These results confirm the role of cell-mediated immunity and highlight the importance of CD4⁺ T cells in controlling HSV shedding, suggesting that therapeutic vaccines designed to reduce transmission by controlling HSV shedding should include specific enhancement of HSV-specific CD4⁺ T cell responses.

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.

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.

[The Spanish Society of Paediatric Infectious Diseases guidelines on the prevention, diagnosis and treatment of neonatal herpes simplex infections]

Neonatal herpes simplex virus infections are rare, but are associated with significant morbidity and mortality. Most newborns acquire herpes simplex virus infection in the peripartum period. For peripartum transmission to occur, women must be shedding the virus in their genital tracts symptomatically or asymptomatically around the time of delivery. There are evidence-based interventions in pregnancy to prevent the transmission to the newborn. Caesarean section should be performed in the presence of herpetic lesions, and antiviral prophylaxis in the last weeks of pregnancy is recommended to suppress genital tract herpes simplex virus at the time of delivery. The diagnosis and early treatment of neonatal herpes simplex virus infections require a high index of suspicion, especially in the absence of skin lesions. It is recommended to rule out herpes simplex virus infections in those newborns with mucocutaneous lesions, central nervous system involvement, or septic appearance. The prognosis of newborns with skin, eye, and/or mouth disease in the high-dose acyclovir era is very good. Antiviral treatment not only improves mortality rates in disseminated and central nervous system disease, but also improves the rates of long-term neurodevelopmental impairment in the cases of disseminated disease. Interestingly, a 6-month suppressive course of oral acyclovir following the acute infection has improved the neurodevelopmental prognosis in patients with CNS involvement.

[Neonatal herpes: Epidemiology, clinical manifestations and management. Guidelines for clinical practice from the French College of Gynecologists and Obstetricians (CNGOF)]

OBJECTIVES

To describe the epidemiology of neonatal herpes and its risk factors, clinical and paraclinic manifestations, propose guidelines for a newborn at risk of neonatal herpes, describe treatment modalities, describe post-natal transmission and its prevention.

METHODS

Bibliographic search from Medline, Cochrane Library databases and research of international clinical practice guidelines.

RESULTS

Neonatal herpes is rare (about 20 cases per year in France) and mainly due to HSV 1 (level of evidence LE3). The main risk factors for mother-to-child transmission are maternal primary episode of genital herpes close to delivery and serotype HSV 1 (LE3). There are three clinical forms of neonatal herpes : SEM infection for skin, eyes and mucosa, central nervous system (CNS) associated infection, and the disseminated infection. Neurological mortality and morbidity depend on the clinical form and the HSV serotype (LE3). In most of the case of neonatal herpes, the mothers have no history of genital herpes (LE3). Fever and vesicular rash may be absent at the time of diagnosis (LE3). In case of suspicion of neonatal herpes, different samples (blood and cerebrospinal fluid) for HSV PCR must be carried out to confirm the diagnosis (Professional consensus). Any newborn suspected of neonatal herpes should be treated with intravenous aciclovir (Grade A) prior to the results of HSV PCR (Professional consensus). In case of maternal genital herpes at delivery, the management of an asymptomatic newborn depends on the evaluation of the risk of transmission. In case of maternal reactivation (low risk of transmission), HSV PCR samples are taken at 24hours of life and the newborn must be follow closely until results. In the case of maternal primary episode or non-primary infection first episode (high risk of transmission), the samples are taken at 24hours of life and intravenous treatment with aciclovir is started (Professional consensus). The treatment of neonatal herpes is based on intravenous aciclovir (60mg/kg/day divided into 3 injections) (Grade C). The duration of the treatment depends on the clinical form (14 days for the SEM infection, 21 days for the other forms) (Professional consensus). A relay with aciclovir per os (300mg/m²/day) for 6 months is recommended to improve the neurological outcome and reduce the risk of reactivation (grade B). Post-natal transmission is mainly due to HSV 1. The rules for the prevention of post-natal transmission must be known by parents and family, but also by nursing staff (Professional consensus). Breastfeeding is not contraindicated in cases of maternal herpes, except if there is herpetic lesion on the nipple (Professional consensus). Parents of newborns at risk for neonatal herpes should receive information on the clinical signs to be monitored at home after hospital discharge (Professional consensus).

CONCLUSIONS

Neonatal herpes is a rare disease with a high morbidity and mortality. The management of a newborn at risk requires good coordination between the obstetric and pediatric teams and parent's information.