Administration of oral acyclovir suppressive therapy after neonatal herpes simplex virus disease limited to the skin, eyes and mouth: results of a phase I/II trial

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.

Viral meningitis in Sudanese children: Differentiation, etiology and review of literature

Diagnosis of viral meningitis (VM) is uncommon practice in Sudan and there is no local viral etiological map. We therefore intended to differentiate VM using standardized clinical codes and determine the involvement of herpes simplex virus types-1 and 2 (HSV-1/2), varicella zoster virus, non-polio human enteroviruses (HEVs), and human parechoviruses in meningeal infections in children in Sudan. This is a cross-sectional hospital-based study. Viral meningitis was differentiated in 503 suspected febrile attendee of Omdurman Hospital for Children following the criteria listed in the Clinical Case Definition for Aseptic/Viral Meningitis. Patients were children age 0 to 15 years. Viral nucleic acids (DNA/RNA) were extracted from cerebrospinal fluid (CSF) specimens using QIAamp® UltraSens Virus Technology. Complementary DNA was prepared from viral RNA using GoScriptTM Reverse Transcription System. Viral nucleic acids were amplified and detected using quantitative TaqMan® Real-Time and conventional polymerase chain reactions (PCRs). Hospital diagnosis of VM was assigned to 0%, when clinical codes were applied; we considered 3.2% as having VM among the total study population and as 40% among those with proven infectious meningitis. Two (0.4%) out of total 503 CSF specimens were positive for HSV-1; Ct values were 37.05 and 39.10 and virus copies were 652/PCR run (261 × 103/mL CSF) and 123/PCR run (49.3 × 103/mL CSF), respectively. Other 2 (0.4%) CSF specimens were positive for non-polio HEVs; Ct values were 37.70 and 38.30, and the approximate virus copies were 5E2/PCR run (~2E5/mL CSF) and 2E2/PCR run (~8E4/mL CSF), respectively. No genetic materials were detected for HSV-2, varicella zoster virus, and human parechoviruses. The diagnosis of VM was never assigned by the hospital despite fulfilling the clinical case definition. Virus detection rate was 10% among cases with proven infectious meningitis. Detected viruses were HSV-1 and non-polio HEVs. Positive virus PCRs in CSFs with normal cellular counts were seen.

Epidemiology and long-term neurological sequelae of childhood herpes simplex CNS infection

AIM

Herpes simplex CNS infection is a rare but important cause of neurological disability. Long term outcomes after HSV CNS infection in Australia have not yet been fully described. We sought to provide a comprehensive review of HSV CNS infection in children using a retrospective 13-year evaluation of statewide laboratory and clinical records and a parent survey conducted at least one year after the initial infection.

METHODS

All positive PCR HSV 1 and 2 results from cerebrospinal fluid (CSF) or brain tissue were obtained from Queensland pathology providers for children aged 0-16 years between 1 January 2005 and 31 December 2017. Clinical data were obtained from patient records and longer-term outcomes via parent survey at least 1 year after initial infection.

RESULTS

Forty-three children were identified over the 13-year period, 17 (39.5%) neonates and 26 (60.4%) non-neonates. The annual incidence for HSV CNS infection in Queensland children aged ≤16 years was 0.3/100 000 (95% confidence intervals (CIs): 0.2-0.4) with neonates at highest risk (incidence 2.5/100 000 live births, 95% CI: 1.5-3.9). HSV 1 was the predominant serotype in both neonates and non-neonates (9/17, 52.9% neonates and 19/26, 73.1% non-neonates). Seven (16.3%) children died, five (5/17, 29.4% neonates), directly attributable to HSV CNS infection (all neonates). Twenty-five (58.1%) had neurological morbidity at discharge (9/17 neonates (52.9%) vs. 16/26 (61.5%) non-neonates) and 20/27 (74.1%) reported long-term neurological morbidity at follow-up (5/9 neonates (55.6%) vs. 15/18 non-neonates (83.3%)). Seven children (two neonates and four non-neonates) with long-term neurological sequelae had no neurological morbidity identified at discharge.

CONCLUSION

Significant long-term neurologic sequelae were seen in children with HSV CNS infection even in children with no neurological disability identified at discharge from hospital. Careful neurodevelopmental follow-up of all children is recommended.

Too Much of a Good Thing: Defining Antimicrobial Therapeutic Targets to Minimize Toxicity

Antimicrobials are a common cause of drug toxicity. Understanding the relationship between systemic antimicrobial exposure and toxicity is necessary to enable providers to take a proactive approach to prevent undesired drug effects. When an exposure threshold has been defined that predicts drug toxicity, therapeutic drug monitoring (TDM) can be performed to assure drug exposure does not exceed the defined threshold. Although some antimicrobials have well-defined dose-dependent toxicities, many other exposure-toxicity relationships have either not been well-defined or, in some cases, not been evaluated at all. In this review, we examine the relationship between exposures and toxicities for antibiotic, antifungal, and antiviral agents. Furthermore, we classify these relationships into four categories: known association between drug exposure and toxicity such that clinical implementation of a specific exposure threshold associated with toxicity for TDM is supported (category 1), known association between drug exposure and toxicity but the specific exposure threshold associated with toxicity is undefined (category 2), association between drug exposure and toxicity has been suggested but relationship is poorly defined (category 3), and no known association between drug exposure and toxicity (category 4). Further work to define exposure-toxicity thresholds and integrate effective TDM strategies has the potential to minimize many of the observed antimicrobial toxicities.

Neonatal Herpes Simplex Virus: The Long Road to Improved Outcomes

Herpes simplex virus (HSV) acquired during delivery places the neonate at risk for mortality or long-term neurodevelopmental disability. Exposure generally occurs from recurrent genital herpes infection, although primary infections result in the highest risk of neonatal disease. Neonates generally present in the second or third week of life with lesions. Encephalitis with seizures indicates the presence of central nervous system involvement, and other end organs may also be impacted. Clinical suspicion for neonatal HSV infection warrants immediate initiation of appropriate antiviral therapy. In the last 50 years, antiviral therapy has progressed from agents with prohibitive toxicity or cumbersome administration to herpes virus-specific agents that dramatically improve clinical outcomes with manageable toxicity. Multicenter clinical trials have demonstrated the superiority of high-dose intravenous acyclovir for acute therapy, followed by long-term oral suppressive therapy. This work has dramatically reduced morbidity and mortality from neonatal HSV, representing the benchmark for future clinical trials in neonatal pharmacotherapy.

Antiviral Therapies for Herpesviruses: Current Agents and New Directions

PURPOSE

The objective of this review was to summarize the recent literature describing the current burden of disease due to herpesviruses in the antiviral and transplant era; describe mechanisms of action of antiviral agents and the development of resistance; summarize the literature of recent antiviral agents brought to market as well as agents under development; and to present literature on future strategies for herpesvirus therapeutics.

METHODS

An extensive search of the medical literature related to antiherpesviral therapy was conducted to compose this narrative review. Literature searches were performed via PubMed and ultimately 137 articles were included as most relevant to the scope of this article.

FINDINGS

Herpesviruses are a family of DNA viruses that are ubiquitous throughout human populations and share the feature of establishing lifelong infections in a latent phase with the potential of periodic reactivation. With the exception of herpes simplex virus, varicella zoster virus, and Epstein-Barr virus, which have a significant disease burden in individuals with normal immune function, the morbidity and mortality of the remaining viruses are primarily associated with the immunocompromised host. Over the last half-century, several agents have been tested in large randomized, placebo-controlled trials that have resulted in safe and effective antiviral agents for the treatment of many of these infections.

IMPLICATIONS

With increasing use of antiherpesviral agents for extended periods, particularly in immunocompromised hosts, the emergence of resistant viruses has necessitated the development of newer agents with novel targets and better side-effect profiles.

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.

Pharmacokinetic considerations in the use of antivirals in neonates

INTRODUCTION

Neonatal patients, because of the inability of their immune system to properly respond to microbial challenge, are highly susceptible to viral infections. Immunoglobulins, monoclonal antibody and antiviral drugs are used for prophylaxis and treatment of viral diseases in neonates. Neonates and, especially, preterm infants differ in drug absorption, distribution, metabolism and excretion from adults and older children.

AREAS COVERED

This review will evaluate deficiencies of neonatal immune responses to microbial challenge that predispose newborns to viral infections, clinical manifestations and the treatment of viral diseases in neonates. We focus on published studies describing antiviral drug pharmacokinetics in neonates and make recommendations on the dosing of these drugs, allowing achievement of maximal clinical benefits in neonates.

EXPERT OPINION

While some efforts were undertaken to study pharmacokinetics and pharmacodynamics of antiviral drugs, much more needs to be done. Current data indicate that the pharmacokinetics of antiviral drugs may vary significantly depending on gestational age, maturation processes of drug-metabolizing enzymes and renal clearance. Specifics of pharmacokinetics of antiviral drugs need to be taken into consideration when they are prescribed to neonates and infants.

New antifungal and antiviral dosing

Neonatal fungal and viral infections are associated with mortality and neurologic impairment among survivors. Advances in pharmacokinetics (PK) and pharmacodynamics (PD) of antimicrobial medications have led to improved dosing guidance for neonates. This article discusses the basic PK/PD properties and dosing of the most common antifungal and antiviral medications used in neonates.

Preventing herpes simplex virus in the newborn

Genital herpes simplex virus (HSV) infections are very common worldwide. Approximately 22% of pregnant women are infected genitally with HSV, and most of them are unaware of this. The most devastating consequence of maternal genital herpes is HSV disease in the newborn. Although neonatal HSV infections remain uncommon, due to the significant morbidity and mortality associated with the infection, HSV infection in the newborn is often considered in the differential diagnosis of ill neonates. This review summarizes the epidemiology and management of neonatal HSV infections and discusses strategies to prevent HSV infection in the newborn.

Antiviral Drug-Resistance Typing Reveals Compartmentalization and Dynamics of Acyclovir-Resistant Herpes Simplex Virus Type-2 (HSV-2) in a Case of Neonatal Herpes

A neonate suffering from herpes simplex virus type 2 disease with central nervous system involvement developed an early recurrence under acyclovir therapy. Isolates from the cerebrospinal fluid and skin lesions were acyclovir resistant, while viruses from blood and trachea were not. Acyclovir combined with foscavir followed by long-term suppressive acyclovir therapy supported normal neurological development.

Management of neonatal herpes simplex virus infection and exposure

Neonatal herpes simplex virus (HSV) infections are rare but are associated with significant morbidity and mortality. Advances in diagnostic modalities to identify these infants, as well as the development of safe and effective antiviral therapy, have revolutionised the management of affected infants. This review will summarise the epidemiology of neonatal HSV infections and discuss the management of infants with HSV exposure and infection.

Neonatal herpes simplex fulminant hepatitis successfully treated with acyclovir

Disseminated neonatal herpes simplex virus (HSV) infection is characterized by progressive multiple organ failure and high mortality rates up to 85% for untreated neonates. It can result from infection with either HSV-1 or HSV-2. We report the first known case of disseminated neonatal herpes associated with fulminant liver failure caused by HSV-2 who survived without liver transplant.

Neonatal herpes simplex virus infections

Neonatal herpes simplex virus infections are uncommon, but because of the morbidity and mortality associated with the infection they are often considered in the differential diagnosis of ill neonates. The use of polymerase chain reaction for diagnosis of central nervous system infections and the development of safe and effective antiviral therapy has revolutionized the diagnosis and management of these infants. Initiation of long-term antiviral suppressive therapy in these infants has led to significant improvement in morbidity. This article summarizes the epidemiology of neonatal herpes simplex virus infections and discusses clinical presentation, diagnosis, management, and follow up of infants with neonatal herpes disease.

Neonatal herpes encephalitis caused by a virologically confirmed acyclovir-resistant herpes simplex virus 1 strain

A neonate with herpes simplex virus 1 encephalitis was treated with intravenous acyclovir. During the course of therapy, the infection became intractable to the treatment and a mutation in the viral thymidine kinase gene (nucleotide G375T, amino acid Q125H) developed. This mutation was demonstrated in vitro to confer acyclovir resistance.

Value of herpes simplex virus type-specific serology: a case report

Genital herpes, usually caused by herpes simplex virus type 2 (HSV-2), is one of the most common sexually transmitted diseases in humans. By contrast, intrauterine HSV-2 infections have been described rarely in the literature. Our report describes a case of neonate who was delivered after 30+2 gestational weeks by cesarean section. He presented with a respiratory distress syndrome resulting in broncho-pulmonary dysplasia. At the age of 6 weeks, a chorioretinal scar was detected. During the 4th month of age, the infant developed recurrent HSV-2 infection with nasal lesions. The retrospective type-specific serologic diagnosis revealed previous HSV-2 infection of the mother resulting in prenatal HSV-2 infection of the infant. In conclusion, intrauterine HSV-2 infections may be underrepresented since they may not be associated with severe congenital malformations and the diagnosis requires the use of HSV type-specific serologic methods not widely applied in microbiological laboratories.

The use of antiviral drugs during the neonatal period

Parenteral therapy of viral infections of the newborn and infant began with vidarabine (adenine arabinoside) for the treatment of neonatal herpes simplex virus (HSV) infections in the early 1980s. Acyclovir has become the treatment of choice for neonatal HSV infections and a variety of other herpesvirus infections. Ganciclovir is beneficial for the treatment of congenital cytomegalovirus (CMV) infections involving the central nervous system (CNS). This article reviews the use of acyclovir and ganciclovir in the treatment of neonatal HSV and congenital CMV infections. A brief summary precedes a detailed discussion of available established and alternative therapeutics.

Oral acyclovir suppression and neurodevelopment after neonatal herpes

BACKGROUND

Poor neurodevelopmental outcomes and recurrences of cutaneous lesions remain unacceptably frequent among survivors of neonatal herpes simplex virus (HSV) disease.

METHODS

We enrolled neonates with HSV disease in two parallel, identical, double-blind, placebo-controlled studies. Neonates with central nervous system (CNS) involvement were enrolled in one study, and neonates with skin, eye, and mouth involvement only were enrolled in the other. After completing a regimen of 14 to 21 days of parenteral acyclovir, the infants were randomly assigned to immediate acyclovir suppression (300 mg per square meter of body-surface area per dose orally, three times daily for 6 months) or placebo. Cutaneous recurrences were treated with open-label episodic therapy.

RESULTS

A total of 74 neonates were enrolled--45 with CNS involvement and 29 with skin, eye, and mouth disease. The Mental Development Index of the Bayley Scales of Infant Development (in which scores range from 50 to 150, with a mean of 100 and with higher scores indicating better neurodevelopmental outcomes) was assessed in 28 of the 45 infants with CNS involvement (62%) at 12 months of age. After adjustment for covariates, infants with CNS involvement who had been randomly assigned to acyclovir suppression had significantly higher mean Bayley mental-development scores at 12 months than did infants randomly assigned to placebo (88.24 vs. 68.12, P=0.046). Overall, there was a trend toward more neutropenia in the acyclovir group than in the placebo group (P=0.09).

CONCLUSIONS

Infants surviving neonatal HSV disease with CNS involvement had improved neurodevelopmental outcomes when they received suppressive therapy with oral acyclovir for 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; CASG 103 and CASG 104 ClinicalTrials.gov numbers, NCT00031460 and NCT00031447, respectively.).

Neonatal herpes simplex virus infections: where are we now?

Neonatal herpes simplex virus (HSV) infection continues to cause significant morbidity and mortality despite advances in diagnosis and treatment. Prior to antiviral therapy, 85% of patients with disseminated HSV disease and 50% of patients with central nervous system disease died within 1 year. The advent of antiviral therapy has dramatically improved the prognosis of neonatal HSV with initially vidarabine and subsequently acyclovir increasing the survival rate of infected neonates and improving long-term developmental outcomes. More recently, polymerase chain reaction has allowed earlier identification of HSV infection and provided a quantitative guide to treatment. Current advances in the treatment of neonatal HSV infections are looking toward the role of prolonged oral suppression therapy in reducing the incidence of recurrent disease. Of concern, however, are increasing reports of acyclovir-resistant HSV isolates in patients following prolonged therapy.

Treatment of herpes simplex virus infections in pediatric patients: current status and future needs

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are members of the Herpesviridae family and are characterized by their ability to establish latency after primary infection and subsequently reactivate. HSV infections in the neonatal and pediatric populations range from uncomplicated mucocutaneous diseases to severe, life-threatening infections involving the central nervous system (CNS). The antiviral agent acyclovir has significantly improved treatment outcomes of HSV infections, including the frequency of mucocutaneous recurrences and mortality associated with CNS and disseminated infections.

Novel approaches in fighting herpes simplex virus infections

The development of novel strategies to eradicate herpes simplex virus (HSV) is a global public health priority. While acyclovir and related nucleoside analogues provide successful modalities for treatment and suppression, HSV remains highly prevalent worldwide and is a major cofactor fueling the HIV epidemic. HSV is the predominant cause of genital ulcerative disease, and neonatal and sporadic infectious encephalitis. Asymptomatic shedding, which occurs more frequently than previously appreciated, contributes to viral transmission. Acyclovir resistance may be problematic for immunocompromised patients and highlights the need for new safe and effective agents. Ideally, vaccines to prevent infection, drugs to inhibit the establishment of or reactivation from latency, or vaginal microbicides to prevent sexual and perinatal transmission are needed to control the epidemic. This review summarizes current therapeutic options and strategies in development.

Antiviral agents for treatment of herpes simplex virus infection in neonates

BACKGROUND

Herpes simplex virus (HSV) is a rare but serious neonatal pathogen. Prior to the availability of antiviral drugs the mortality associated with all but localised neonatal infection was high, with 85% of infants with disseminated HSV infection and 50% of infants with encephalitis dying by one year of age. The morbidity in the survivors of multiorgan infection was also high, with up to 50% experiencing long-term neurological sequelae.

OBJECTIVES

To determine the effect of antiviral agents in the treatment of neonatal HSV infections on mortality, progression of disease and neurodevelopmental sequelae at approximately one year. The secondary objective was to assess the effect of antiviral agents on major complications associated with the use of these agents including nephrotoxicity and bone marrow suppression.

SEARCH STRATEGY

Trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2008), MEDLINE (1996 - Nov 2008), EMBASE (1982 - Nov 2008) and reference lists of published trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of antiviral therapy in infants less than one month of age with virologically proven HSV infection were included.

DATA COLLECTION AND ANALYSIS

Data were extracted and the analyses performed independently by two review authors. Studies were analysed for methodological quality using the criteria of the Cochrane Neonatal Review Group. All data were analysed using RevMan 5.1. When possible, meta-analysis was performed to calculate typical relative risk, typical risk difference, along with their 95% confidence intervals (CI).

MAIN RESULTS

Two eligible studies of a total of 273 infants were included. Both studies were randomized controlled trials. One study treated 63 infants with vidarabine or placebo (Whitley 1980) and the other study treated 210 infants with aciclovir or vidarabine (Whitley 1991).In the study comparing vidarabine with placebo (Whitley 1980), infants with all forms of neonatal HSV disease were included [disseminated disease, central nervous system (CNS) disease alone, and skin, eye and mouth (SEM) disease].There was no significant reduction in the risk of mortality when analyzed as an entire group; however, mortality was significantly reduced when data from infants with CNS disease or disseminated disease were combined. There was no difference in the rate of neurological abnormalities in survivors at one year when analyzed as an entire group or by disease category.There was no difference between aciclovir and vidarabine (Whitley 1991) in preventing mortality from neonatal HSV disease, in preventing disease progression, in reducing the incidence of neurological abnormality at one year, or in the incidence of drug-induced renal or bone marrow toxicity. In infants with SEM disease, there was no significant difference in neurological outcome with aciclovir compared vidarabine treatment. Both drugs were well tolerated in the newborn period.

AUTHORS' CONCLUSIONS

There is insufficient trial evidence to evaluate the effects of antiviral agents with controls or with each other. The rarity of the condition makes effectively powered clinical trials difficult to perform. The efficacy of newer antiviral agents with better bioavailability (e.g. valaciclovir, valganciclovir) for the treatment of neonatal disease needs to be evaluated in randomised trials. The efficacy of oral formulations need to be evaluated as they may be useful for infants with skin, eye or mouth HSV disease or in the treatment of infants with recurrences after the neonatal period.

Antiviral agents for treatment of herpes simplex virus infection in neonates

BACKGROUND

Herpes simplex virus (HSV) is a rare but serious neonatal pathogen. Prior to the availability of antiviral drugs the mortality associated with all but localised neonatal infection was high, with 85% of infants with disseminated HSV infection and 50% of infants with encephalitis dying by one year of age. The morbidity in the survivors of multiorgan infection was also high, with up to 50% experiencing long-term neurological sequelae.

OBJECTIVES

To determine the effect of antiviral agents in the treatment of neonatal HSV infections on mortality, progression of disease and neurodevelopmental sequelae at approximately one year. The secondary objective was to assess the effect of antiviral agents on major complications associated with the use of these agents including nephrotoxicity and bone marrow suppression.

SEARCH STRATEGY

Trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2008), MEDLINE (1996 - Nov 2008), EMBASE (1982 - Nov 2008) and reference lists of published trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of antiviral therapy in infants less than one month of age with virologically proven HSV infection were included.

DATA COLLECTION AND ANALYSIS

Data were extracted and the analyses performed independently by two review authors. Studies were analysed for methodological quality using the criteria of the Cochrane Neonatal Review Group. All data were analysed using RevMan 5.1. When possible, meta-analysis was performed to calculate typical relative risk, typical risk difference, along with their 95% confidence intervals (CI).

MAIN RESULTS

Two eligible studies of a total of 273 infants were included. Both studies were randomized controlled trials. One study treated 63 infants with vidarabine or placebo (Whitley 1980) and the other study treated 210 infants with aciclovir or vidarabine (Whitley 1991).In the study comparing vidarabine with placebo (Whitley 1980), infants with all forms of neonatal HSV disease were included [disseminated disease, central nervous system (CNS) disease alone, and skin, eye and mouth (SEM) disease].There was no significant reduction in the risk of mortality when analyzed as an entire group; however, mortality was significantly reduced when data from infants with CNS disease or disseminated disease were combined. There was no difference in the rate of neurological abnormalities in survivors at one year when analyzed as an entire group or by disease category.There was no difference between aciclovir and vidarabine (Whitley 1991) in preventing mortality from neonatal HSV disease, in preventing disease progression, in reducing the incidence of neurological abnormality at one year, or in the incidence of drug-induced renal or bone marrow toxicity. In infants with SEM disease, there was no significant difference in neurological outcome with aciclovir compared vidarabine treatment. Both drugs were well tolerated in the newborn period.

AUTHORS' CONCLUSIONS

There is insufficient trial evidence to evaluate the effects of antiviral agents with controls or with each other. The rarity of the condition makes effectively powered clinical trials difficult to perform. The efficacy of newer antiviral agents with better bioavailability (e.g. valaciclovir, valganciclovir) for the treatment of neonatal disease needs to be evaluated in randomised trials. The efficacy of oral formulations need to be evaluated as they may be useful for infants with skin, eye or mouth HSV disease or in the treatment of infants with recurrences after the neonatal period.

Herpes simplex virus infection in pregnancy and in neonate: status of art of epidemiology, diagnosis, therapy and prevention

Herpes simplex virus (HSV) infection is one of the most common viral sexually transmitted diseases worldwide. The first time infection of the mother may lead to severe illness in pregnancy and may be associated with virus transmission from mother to foetus/newborn. Since the incidence of this sexually transmitted infection continues to rise and because the greatest incidence of herpes simplex virus infections occur in women of reproductive age, the risk of maternal transmission of the virus to the foetus or neonate has become a major health concern. On these purposes the Authors of this review looked for the medical literature and pertinent publications to define the status of art regarding the epidemiology, the diagnosis, the therapy and the prevention of HSV in pregnant women and neonate. Special emphasis is placed upon the importance of genital herpes simplex virus infection in pregnancy and on the its prevention to avoid neonatal HSV infections.

Persistence of herpes simplex virus DNA in cerebrospinal fluid of neonates with herpes simplex virus encephalitis

OBJECTIVE

The significance of detecting herpes simplex virus (HSV) DNA in the cerebrospinal fluid (CSF) of infants with HSV encephalitis after receipt of prolonged therapy with high-dose (60 mg kg(-1) day(-1)) acyclovir is unknown. We report the clinical and laboratory characteristics, neuroimaging studies and outcomes of four neonates with HSV encephalitis who had persistence of CSF HSV DNA, by polymerase chain reaction (PCR) after 15 to 21 days of high-dose acyclovir therapy.

STUDY DESIGN

Retrospective chart review.

RESULTS

All four infants had abnormal neuroimaging studies and subsequently experienced severe developmental delay or death.

CONCLUSION

A persistently positive CSF HSV PCR in neonates may be another risk factor for worse neurodevelopmental outcome. Prospective studies are needed to document how often HSV DNA persists in CSF, elucidate whether it represents an initially high CSF viral load, ongoing viral replication or viral resistance, and determine its possible association with neurodevelopmental impairment.

The impact of cesarean delivery on transmission of infectious agents to the neonate

The rate of cesarean deliveries has increased dramatically over the past decade. Studies to date have highlighted a number of factors on the part of the treating physician and the expectant mother contributing to this increase. Maternal infections are not a major cause of this increase. There are a limited number of infections in a pregnant woman that warrant cesarean delivery to prevent perinatal transmission. This article outlines those infections known to be transmitted perinatally through the infected birth canal and details the current recommendations for cesarean delivery. Pregnant women with active genital herpes lesions or with known herpes simplex virus infection and a prodromal illness consistent with recurrence at the time of presentation in labor should undergo cesarean delivery. Pregnant women who are HIV infected and have detectable viremia (>1000 copies/mL) should be counseled regarding the potential benefits of cesarean delivery as an adjunct to antiretroviral therapy. Hepatitis C virus (HCV) can be transmitted intrapartum, but prevention of HCV transmission by cesarean delivery has not been proved effective and is not generally indicated. A limited number of other infectious agents can be transmitted through the birth canal but do not constitute an indication for cesarean delivery.

Herpes simplex virus infections of the newborn

Herpes simplex virus (HSV) infections are fortunately quite rare in the neonatal population. Nevertheless, due to their life-threatening nature and the tremendous damage that surviving infants can incur, neonatal HSV is actually considered in a differential diagnosis relatively commonly. The availability of safe and effective antiviral therapy for the management of neonatal HSV also can accelerate a clinician's decision to consider HSV as the cause of a neonate's disease presentation, and then to obtain appropriate diagnostic studies and empirically institute antiviral treatment. Decisions on whether to continue antiviral therapy for a full course are predicated on the appropriate interpretation of these diagnostic studies as they subsequently are reported to the treating physician. For HSV-infected neonates, the duration of parenteral acyclovir therapy ranges from 14 to 21 days, depending on the extent of disease. Use of subsequent oral suppressive antiviral therapy is under investigation in randomized controlled trials, and at this time cannot be routinely recommended. This article will summarize the current state of neonatal HSV disease presentation, diagnosis, and management.

Diagnosis of herpes simplex virus infections of the CNS

Advances in the diagnosis of herpes simplex virus infections of the CNS have occurred rapidly over the past 10 years. The development and application of PCR technology to the detection of herpes simplex virus DNA from cerebrospinal fluid has resulted in tremendous improvements in the management of patients with suspected herpes simplex virus CNS infections, not the least of which is decreasing the necessity for invasive brain biopsy to establish the diagnosis. The pace of discovery has continued in recent years with the development of more rapid DNA amplification techniques that do not require postamplification analysis using amplified products (real-time PCR). However, despite the power of these new diagnostic modalities, test results must always be considered in the context of the patient, and physician judgment should never be usurped by technological advances. This article will summarize the advances in the diagnosis of herpes simplex virus CNS disease within the context of how these advances can enhance the care of individual patients.

Herpes simplex and varicella-zoster virus infections during pregnancy: current concepts of prevention, diagnosis and therapy. Part 1: Herpes simplex virus infections

Primary herpes simplex virus (HSV) infection may lead to severe illness in pregnancy and may be associated with transplacental virus transmission and fetal infection. The consequences may be abortion, stillbirth and congenital malformations. In neonates, the clinical findings after intrauterine HSV infection are characterized by skin lesions, diseases of the eye and neurologic damage. Herpes genitalis of pregnant women at the time of labor may result in life-threatening neonatal herpes. Currently, neither active nor passive immunization is available to prevent HSV infections during pregnancy and in the newborn infant. Therefore, antiviral treatment using aciclovir and/or valaciclovir must be considered in all primary episodes of genital herpes as well as in neonates who show signs of either infection. Clinical herpes lesions of the genitalia and/or positive test for virus detection at the time of delivery are an indication for cesarean section. However, this surgical intervention may be reduced by suppressive treatment of recurrent genital herpes with aciclovir or valaciclovir.

Herpes simplex virus infections in preterm infants

OBJECTIVE

Neonatal herpes simplex virus infections cause significant neonatal mortality and morbidity, but the course and prognosis in preterm infants is not well documented. We performed a retrospective review of herpes simplex virus infections at out institution within the first 30 days after birth in infants who were born at <37 weeks to help better define the symptoms and signs of herpes simplex virus infections in preterm infants and to assist in prognosis.

METHODS

Hospital databases were reviewed to identify culture- or polymerase chain reaction-proven cases of herpes simplex virus-1 or herpes simplex virus-2 infections that occurred in preterm newborns between 1989 and 2003. Maternal and neonatal histories, clinical features, and laboratory results were reviewed systematically.

RESULTS

Ten preterm singletons and a set of twins were infected with herpes simplex virus-2 during the first month after birth. No mother had herpes simplex virus lesions at delivery, but a history of genital herpes simplex or other sexually transmitted infections was prevalent among the mothers. Infants presented with either disseminated disease or encephalitis. All infants with disseminated disease (n = 9) died, whereas the 3 infants with encephalitis survived. All infants in the cohort developed respiratory distress, and consistent with the prominence of respiratory symptoms, viral cultures of the respiratory tract were consistently positive. Ten of 12 infants received acyclovir, but despite treatment within 48 hours of symptoms, infants with disseminated disease deteriorated rapidly and died. Two of 3 infants who received high-dosage (60 mg/kg per day) acyclovir survived.

CONCLUSIONS

Herpes simplex virus infections in preterm infants usually present during the first 2 weeks of life with respiratory distress and a high incidence of disseminated disease. Viral respiratory cultures have a high yield for documentation of infection. The morbidity of herpes simplex virus in this population may be attributable to a relatively immature immune system in this population. Additional studies are necessary to delineate the evolution of herpes simplex virus disease in preterm infants and the role of antiviral therapy in mitigating the sequelae of herpes simplex virus infections in this population.

Valacyclovir prophylaxis to prevent recurrent herpes at delivery: a randomized clinical trial

OBJECTIVE

To measure the efficacy of valacyclovir suppression in late pregnancy to reduce the incidence of recurrent genital herpes in labor and subsequent cesarean delivery.

METHODS

A total of 350 pregnant women with a history of genital herpes were assigned randomly to oral valacyclovir 500 mg twice a day or an identical placebo from 36 weeks of gestation until delivery. In labor, vulvovaginal herpes simplex virus (HSV) culture and polymerase chain reaction (PCR) specimens were collected. Vaginal delivery was permitted if no clinical recurrence or prodromal symptoms were present. Neonatal HSV cultures and laboratory tests were obtained, and infants were followed up for 1 month after delivery. Data were analyzed using chi2 and Student t tests.

RESULTS

One hundred seventy women treated with valacyclovir and 168 women treated with placebo were evaluated. Eighty-two percent of the women had recurrent genital herpes; 12% had first episode, nonprimary genital herpes; and 6% had first episode, primary genital herpes. At delivery, 28 women (8%) had recurrent genital herpes requiring cesarean delivery: 4% in the valacyclovir group and 13% in the placebo group (P = .009). Herpes simplex virus was detected by culture in 2% of the valacyclovir group and 9% [corrected] of the placebo group (P =.02). No infants were diagnosed with neonatal HSV, and there were no significant differences in neonatal complications. There were no significant differences in maternal or obstetric complications in either group.

CONCLUSION

Valacyclovir suppression after 36 weeks of gestation significantly reduces HSV shedding and recurrent genital herpes requiring cesarean delivery.

LEVEL OF EVIDENCE

I.

Herpes Simplex Virus Infections in Neonates and Early Childhood

Of the commonly considered congenital infections, those caused by cytomegalovirus (CMV), syphilis, and herpes simplex virus (HSV) are frequently (CMV, HSV) or exclusively (syphilis) acquired sexually by the mother, with subsequent transmission to the developing fetus. Of the other commonly considered congenital infections, including rubella and toxoplasma infections, the mother is exposed to the infectious agent via interpersonal or environmental contacts. Unlike each of these other pathogens, which are transmitted transplacentally to the developing fetus following maternal infection though, HSV usually is transmitted perinatally as the neonate is exposed to the virus during passage through an infected birth canal. This difference in timing of acquisition of infection has had important consequence in the therapeutic advances achieved during the last 30 years in the management of neonatal HSV infections. Because the time period between the acquisition of infection and initiation of effective antiviral therapy is shorter in neonatal herpes than in congenital toxoplasmosis or CMV infections, the outcomes of therapy have the potential to be markedly different. This article will summarize the current state of neonatal HSV disease presentation, diagnosis, and management.

Pharmacokinetics of antivirals in neonate

BACKGROUND

About 1000 neonates with HIV infection are born every day worldwide. The antiviral therapy for newborn infants is a real necessity. Pharmacokinetics is an important contribution to therapy and no review has been published on the pharmacokinetics of antivirals in neonates up to now.

AIMS

This article provides a review on the pharmacokinetics of antivirals in the neonate. The pharmacokinetic parameters in the neonate are compared with those of the adult, and when possible, the pharmacokinetic parameters were compared in neonates of different ages.

RESULTS

Zidovudine is the antiviral with the largest amount of information on its pharmacokinetics. The clearance (Cl; l/h/kg) of zidovudine is 0.15 (premature), 0.34 (1 day), 0.69 (7 days), 0.65 (< or =14 days), 1.14 (>14 days) and 1.56 (adult). t(1/2) (h) of zidovudine is 7.2 (premature), 4.2 (1 day), 4.0 (7 days), 3.1 (< or =14 days), 1.9 (>14 days) and 1.1 (adult). Zidovudine is mainly eliminated by conjugation with glucuronic acid and glucuronosyl transferase develops postnatally. Cl of lamivudine is 0.19 (1 day), 0.32 (7 days) and 0.30 (adult) and the Cl (l/h/m2) of didanosine is 65 (1 day) and 271 (7 days). A greater volume of distribution (Vd) has been observed in the neonate compared with the adult for nelfinavir, nevirapine and pleconaril.

CONCLUSIONS

The pharmacokinetic parameters of antivirals differ in the neonate and in the adult. The Cl is reduced and t(1/2) is increased in the neonate compared with the adult for zidovudine, lamivudine and ganciclovir. t(max) is generally greater in the neonate than in the adult due to reduced absorption rate in the neonate. The Vd of nelfinavir, nevirapine and pleconaril is greater in the newborn than in the adult. The neonate is a developing organism and the pharmacokinetic parameters of antivirals vary during the first weeks of life.

Antiviral therapies in children: has their time arrived?

The increase in the number and classes of antiviral agents that has occurred since the 1980s is remarkable. The rapid expansion in therapeutic options for previously untreatable illnesses challenges clinicians to gain familiarity and experience with these new drugs, especially with regard to their use in children. This article describes the clinical utilities, pharmacokinetics, and adverse effects of these new drugs to empower practitioners to use them appropriately.

Herpes Simplex Virus Infections of the Newborn

Herpes simplex virus (HSV) infection in newborns is an important cause of death and permanent neurodevelopmental disability among young children. Neonatal HSV infections can be categorized as 1) mucocutaneous (skin-eyes-mouth), 2) disseminated, or 3) encephalitic. In addition, congenital HSV infection, a distinct clinical syndrome, accounts for approximately 5% of HSV infections identified in the neonatal period. Polymerase chain reaction greatly enhances the clinician's ability to diagnosis HSV infections, but as many as 25% of infants with neonatal HSV encephalitis have negative polymerase chain reaction studies of cerebrospinal fluid. Infants with proven or suspected HSV infections should receive acyclovir 60 mg/kg/day divided every 8 hours for 14 days if disease is restricted to the skin, eyes, or mucous membranes and for 21 days if the infant has disseminated infection or encephalitis. The benefit of long-term suppression therapy after completion of the initial treatment regimen has not been established definitively. Despite therapy with acyclovir, the best available anti-HSV drug, a substantial number of HSV-infected infants with disseminated infections or encephalitis die or have long-term neurodevelopmental sequelae.

Herpes simplex virus encephalitis during suppressive therapy with acyclovir in a premature infant

Cutaneous herpes simplex virus type 2 (HSV-2) infection was recognized at 19 days of age in a 1415-g female infant born at 31 weeks of gestation. Cerebrospinal fluid (CSF) HSV polymerase chain reaction (PCR) was negative, and MRI of the brain was normal. After a 14-day course of high-dose intravenous acyclovir, the infant developed a cutaneous recurrence at 38 days of age. CSF HSV PCR again was negative. She was subsequently begun on oral acyclovir to prevent cutaneous reactivation of HSV. At 3 months of age, the infant developed HSV encephalitis as manifested by fever, seizures, abnormal CSF indices, abnormal brain MRI, and positive CSF HSV PCR. No cutaneous disease was present. It is not known whether the HSV encephalitis in our patient represented reactivation of previously unrecognized central nervous system infection or new onset of central nervous system disease as a result of spread from other tissue or site to the brain. The failure of oral acyclovir to prevent such an occurrence, however, highlights gaps in our understanding of the pathogenesis of neonatal HSV disease and questions the use of acyclovir suppression to prevent neurologic sequelae.

Improved neurodevelopmental outcomes following long-term high-dose oral acyclovir therapy in infants with central nervous system and disseminated herpes simplex disease

OBJECTIVE

Infants with neonatal herpes, classified as central nervous system or disseminated disease, have a high incidence of moderate and severe neurologic deficits despite standard acute therapy.

STUDY DESIGN

Following completion of parenteral therapy, infants with central nervous system and/or disseminated disease received 2 years of continuous oral acyclovir therapy. Target minimum peak serum acyclovir concentrations were >2 microg/ml for the first three patients, and >3 microg/ml for the subsequent 13 patients. Safety assessments were made every 3 months. We evaluated neurodevelopmental outcomes with Bayley Scales of Infant Development.

RESULTS

A total of 16 consecutive herpes simplex virus-infected infants born during 1990 to 2003 received the treatment plan; 13/16 infants had central nervous system disease; 3 had disseminated disease without central nervous system involvement. A total of 69% (11/16) had Bayley scores in the normal range for mental development and 79% (11/14) had motor scores in the normal range. At the final assessment, five children had developmental delays. One child had severe mental delay with normal motor development. Four children had mild mental delays, with severe motor delays in three. All children were independently mobile, without seizure disorder, had normal vision, and had speech development. During the 2-year course of treatment, five children had brief recurrences of dermal lesions, and none had evidence of neurologic deterioration. There were no serious or sustained adverse drug reactions.

CONCLUSION

This pilot study reports improved outcomes in a small cohort of infants with a prolonged course of oral acyclovir. A minority of these children exhibited mild or significant developmental delays. Further investigation of this approach to treatment is warranted.

Molecular methods for diagnosis of viral encephalitis

Hundreds of viruses cause central nervous system (CNS) disease, including meningoencephalitis and postinfectious encephalomyelitis, in humans. The cerebrospinal fluid (CSF) is abnormal in >90% of cases; however, routine CSF studies only rarely lead to identification of a specific etiologic agent. Diagnosis of viral infections of the CNS has been revolutionized by the advent of new molecular diagnostic technologies to amplify viral nucleic acid from CSF, including PCR, nucleic acid sequence-based amplification, and branched-DNA assay. PCR is ideally suited for identifying fastidious organisms that may be difficult or impossible to culture and has been widely applied for detection of both DNA and RNA viruses in CSF. The technique can be performed rapidly and inexpensively and has become an integral component of diagnostic medical practice in the United States and other developed countries. In addition to its use for identification of etiologic agents of CNS disease in the clinical setting, PCR has also been used to quantitate viral load and monitor duration and adequacy of antiviral drug therapy. PCR has also been applied in the research setting to help discriminate active versus postinfectious immune-mediate disease, identify determinants of drug resistance, and investigate the etiology of neurologic disease of uncertain cause. This review discusses general principles of PCR and reverse transcription-PCR, including qualitative, quantitative, and multiplex techniques, with comment on issues of sensitivity, specificity, and positive and negative predictive values. The application of molecular diagnostic methods for diagnosis of specific infectious entities is reviewed in detail, including viruses for which PCR is of proven efficacy and is widely available, viruses for which PCR is less widely available or for which PCR has unproven sensitivity and specificity, and nonviral entities which can mimic viral CNS disease.