Failure of antepartum maternal cultures to predict the infant's risk of exposure to herpes simplex virus at delivery

Vertical mother-to-infant transmission of herpes simplex virus 2 is correlated with tropism due to mutations in viral UL13

Although neonates are commonly exposed to vaginal herpes simplex virus (HSV)-2, neonatal herpes is rare. Therefore, we analyzed paired infant and maternal HSV-2 isolates from two cases of mother-to-infant transmission to identify viral factors contributing to vertical transmission. Sixteen infant isolates with neonatal herpes and 27 genital isolates in their third trimester were included. The infant isolates were significantly more temperature-independent than the maternal isolates. Sequence comparison revealed viral UL13 protein kinase (UL13-PK) mutation in the infant isolates in both cases. In the expanded cohort, infant isolates (5/18) had significantly more UL13-PK mutations than genital isolates (1/29). Isolates within 8 days post-birth (3/4) had a significantly higher frequency of UL13-PK mutation than those after 9 days (2/14), suggesting a close association between UL13-PK mutations and vertical transmission. Elongation factor 1-delta was identified as a target of UL13-PK by proteomic analysis of UL13-PK-positive and -negative HepG2 cells. The mixed infant isolates with the intact and mutated UL13-PK conferred altered cell tropism, temperature independence adapting to fetal temperature, and better growth properties in Vero and hepatoblastoma HepG2 cells than in HSV-2 with intact and mutated UL13-PK alone, indicating that viral UL13-PK mutation is essential for vertical HSV-2 transmission.

Neonatal Herpes Simplex Virus Disease: Updates and Continued Challenges

This article defines neonatal herpes simplex virus (HSV) disease and describes the progress over the past 40 years that has revolutionized the management of HSV disease in neonates to improve their outcomes. These advancements include the introduction of acyclovir in the 1980s, polymerase chain reaction (PCR) for the detection of HSV DNA in the 1990s, and recommendations on managing infants born to mothers with active genital lesions. Despite these advancements, however, there remain high morbidity and mortality in affected neonates, with need for continued improvement. Areas of high interest include vaccine development and rapid PCR detection at time of delivery.

Management of Genital Herpes in Pregnancy: ACOG Practice Bulletinacog Practice Bulletin, Number 220

Genital herpes simplex virus (HSV) infection during pregnancy poses a risk to the developing fetus and newborn. Genital herpes is common in the United States. Among 14- to 49-year-old females, the prevalence of HSV-2 infection is 15.9%. However, the prevalence of genital herpes infection is higher than that because genital herpes is also caused by HSV-1 (). Because many women of childbearing age are infected or will be infected with HSV, the risk of maternal transmission of this virus to the fetus or newborn is a major health concern. This document has been revised to include that for women with a primary or nonprimary first-episode genital HSV infection during the third trimester of pregnancy, cesarean delivery may be offered due to the possibility of prolonged viral shedding.

Prevention and treatment of neonatal herpes simplex virus infection

Herpes simplex virus (HSV), a member of the Herpesviridae family, is a well-known cause of infections including genital herpes and herpes labialis in the adolescent and adult population. Transmission of HSV infection to an infant during the first 4-6 weeks of life can lead to devastating disease with the potential for poor outcomes. Early diagnosis is imperative when evaluating neonatal HSV infection in order to prevent further disease progression, neurological complications, and even death. In the past 4 decades, significant advancements have been made in the diagnosis, treatment, and prevention of neonatal HSV infection, but there remains room for improvement as efforts continue to reduce the burden of disease caused by this infection.

No. 208-Guidelines for the Management of Herpes Simplex Virus in Pregnancy

OBJECTIVE

To provide recommendations for the management of genital herpes infection in women who want to get pregnant or are pregnant and for the management of genital herpes in pregnancy and strategies to prevent transmission to the infant.

OUTCOMES

More effective management of complications of genital herpes in pregnancy and prevention of transmission of genital herpes from mother to infant.

EVIDENCE

Medline was searched for articles published in French or English related to genital herpes and pregnancy. Additional articles were identified through the references of these articles. All study types and recommendation reports were reviewed.

VALUES

Recommendations were made according to the guidelines developed by the Canadian Task Force on Preventive Health Care.

RECOMMENDATIONS

VALIDATION: These guidelines have been reviewed and approved by the Infectious Diseases Committee of the SOGC.

SPONSOR

The Society of Obstetricians and Gynaecologists of Canada.

Herpesviridae Infection: Prevention, Screening, and Management

Bacterial, viral, and parasitic pathogens add significant morbidity and even mortality to pregnancy-with adverse effects extending to both the gravida and the newborn. Three herpesviruses deserve considerable attention given the effects of perinatal infection on obstetric outcomes, specifically maternal and neonatal morbidity. In the following review, we will provide a description of cytomegalovirus, herpes simplex virus, and varicella zoster virus. For each viral pathogen, we will describe the epidemiology, natural history, screening and diagnosis modalities, treatments, and implications for antepartum care. Furthermore, we will highlight future directions of work in reducing the morbidities associated with these viral pathogens.

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.

Neonatal Herpes Simplex Virus Infection

Herpes simplex virus (HSV) 1 and HSV-2 infections are highly prevalent worldwide and are characterized by establishing lifelong infection with periods of latency interspersed with periodic episodes of reactivation. Acquisition of HSV by an infant during the peripartum or postpartum period results in neonatal HSV disease, a rare but significant infection that can be associated with severe morbidity and mortality, especially if there is dissemination or central nervous system involvement. Diagnostic and therapeutic advances have led to improvements in mortality and, to a lesser extent, neurodevelopmental outcomes, but room exists for further improvement.

Neonatal herpes simplex virus infection: epidemiology and treatment

Herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) are highly prevalent viruses capable of establishing lifelong infection. Genital herpes in women of childbearing age represents a major risk for mother-to-child transmission (MTCT) of HSV infection, with primary and first-episode genital HSV infections posing the highest risk. The advent of antiviral therapy with parenteral acyclovir has led to significant improvement in neonatal HSV disease mortality. Further studies are needed to improve the clinician's ability to identify infants at increased risk for HSV infection and prevent MTCT, and to develop novel antiviral agents with increased efficacy in infants with HSV infection.

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.

Mother-to-Child Transmission of Herpes Simplex Virus

Infections with herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2), both alpha herpesviruses, are highly prevalent worldwide. Both HSV types commonly cause genital infection, which, when acquired or reactivated during pregnancy, carries with it the risk of transmission to the fetus or neonate. Women who acquire primary or first-episode genital herpes during pregnancy are at greater risk for transmitting the infection than are women with recurrent genital herpes. Because viral infection and reactivation are frequently asymptomatic, many affected women are unaware of their infection and risk of transmission to their infants. Neonatal HSV infection can have devastating long-term consequences, especially when the central nervous system (CNS) is involved. Treatment of affected neonates with intravenous acyclovir has improved outcomes but there is room for further improvement, especially in regard to CNS disease. Working with pregnant women to prevent mother-to-child transmission of HSV is an important component in reducing the overall disease burden of neonatal HSV infections.

Prospects and perspectives for development of a vaccine against herpes simplex virus infections

Herpes simplex viruses 1 and 2 are human pathogens that lead to significant morbidity and mortality in certain clinical settings. The development of effective antiviral medications, however, has had little discernible impact on the epidemiology of these pathogens, largely because the majority of infections are clinically silent. Decades of work have gone into various candidate HSV vaccines, but to date none has demonstrated sufficient efficacy to warrant licensure. This review examines developments in HSV immunology and vaccine development published since 2010, and assesses the prospects for improved immunization strategies that may result in an effective, licensed vaccine in the near future.

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 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 simplex virus infection

Neonatal herpes, seen roughly in 1 of 3000 live births in the United States, is the most serious manifestation of herpes simplex virus (HSV) infection in the perinatal period. Although acyclovir therapy decreases infant mortality associated with perinatal HSV transmission, development of permanent neurological disabilities is not uncommon. Mother-to-neonate HSV transmission is most efficient when maternal genital tract HSV infection is acquired proximate to the time of delivery, signifying that neonatal herpes prevention strategies need to focus on decreasing the incidence of maternal infection during pregnancy and more precisely identifying infants most likely to benefit from prophylactic antiviral therapy.

Diagnostics for Herpes Simplex Virus

Herpes simplex virus (HSV) is one of the most common, yet frequently overlooked, sexually transmitted infections. Since the type of HSV infection affects prognosis and subsequent counseling, type-specific testing to distinguish HSV-1 from HSV-2 is recommended. Although PCR has been the diagnostic standard for HSV infections of the central nervous system, until now viral culture has been the test of choice for HSV genital infection. However, HSV PCR, with its consistently and substantially higher rate of HSV detection, will likely replace viral culture as the gold standard for the diagnosis of genital herpes in people with active mucocutaneous lesions, regardless of anatomic location or viral type. Alternatively, type-specific serologic tests based on glycoprotein G should be the test of choice to establish the diagnosis of HSV infection when no active lesion is present. Given the difficulty in making the clinical diagnosis of HSV, the growing worldwide prevalence of genital herpes and the availability of effective antiviral therapy, there is an increased demand for rapid, accurate laboratory diagnosis of patients with HSV.

The diagnosis of genital herpes - beyond culture: An evidence-based guide for the utilization of polymerase chain reaction and herpes simplex virus type-specific serology

Accurate identification of persons with genital herpes is necessary for optimal patient management and prevention of transmission. Because of inherent inaccuracies, clinical diagnosis of genital herpes should be confirmed by laboratory testing for the causative agents herpes simplex virus type 1 (HSV-1) and HSV type 2 (HSV-2). Further identification of the HSV type is valuable for counselling on the natural history of infection and risk of transmission. Laboratory methods include antigen detection, culture, polymerase chain reaction (PCR) and conventional and type-specific serology (TSS). PCR has, by far, the greater sensitivity and should be the test of choice for symptomatic cases. HSV-2 TSS is indicated for patients with genital lesions in whom antigen detection, culture or PCR fail to detect HSV, and for patients who are asymptomatic but have a history suggestive of genital herpes. HSV-2 TSS is further indicated for patients infected with HIV. HSV-2 TSS along with HSV-1 TSS may be considered, as appropriate, in evaluating infection and/or immune status in couples discordant for genital herpes, women who develop their first clinical episode of genital herpes during pregnancy, asymptomatic pregnant women whose partners have a history of genital herpes or HIV infection, and women contemplating pregnancy or considering sexual partnership with those with a history of genital herpes. The above should be performed in conjunction with counselling of infected persons and their sex partners.

Rapid polymerase chain reaction assay to detect herpes simplex virus in the genital tract of women in labor

OBJECTIVE

To develop a rapid quantitative real-time polymerase chain reaction (PCR) to detect herpes simplex virus (HSV) in the genital secretions of women that may be used in labor.

METHODS

Samples of genital secretions from women in labor, swabs of active genital lesions, and swabs of buffer solution were analyzed using a newly developed rapid HSV PCR assay to detect HSV glycoprotein B gene and quantitate virion copy number. A previously validated TaqMan PCR to detect HSV glycoprotein B gene was performed as the comparator gold standard. Positivity determination that optimized sensitivity and specificity was determined with receiver operating characteristic curves.

RESULTS

The median time to result for rapid HSV PCR was 2 hours (range 1.5-3.5 hours). A positivity determination rule that required both wells of the rapid test to detect 150 copies or greater of HSV per milliliter maximized specificity (96.7%) without appreciable loss of sensitivity (99.6%). Among positive samples, the correlation between the rapid test and TaqMan for the quantity of HSV isolated was excellent (R=0.96, P<.001). The rapid test had a positive predictive value of 96.7% and a negative predictive value of 99.6% in a population with HSV shedding prevalence of 10.8%, based on the prevalence of genital HSV previously found among HSV-2 seropositive women in labor.

CONCLUSION

Rapid HSV PCR provides results with excellent sensitivity and specificity within a timeframe that could inform clinical decision making for identifying neonates at risk of neonatal HSV infection.

LEVEL OF EVIDENCE

II.

The acceptance of HSV-testing partners of HSV-2 seronegative pregnant women

OBJECTIVES

To estimate the acceptance of HSV testing partners of HSV seronegative pregnant women and identify associated factors.

STUDY DESIGN

Consecutive women identified as HSV-2 seronegative during routine testing in pregnancy were asked to invite their partners for HSV testing to identify serodiscordance. Logistic regression identified factors associated with partner testing.

RESULTS

Between 2001 to 2006, 315 women enrolled (28% of those approached) and 242 (77%) partners were tested. Married couples were most likely to be tested [adjusted odds ratio (aOR) 7.72, 95% CI: 2.47-24.15]. Partners of black women (aOR 0.17, 95% CI: 0.04-0.71), and those with at least a college degree (aOR 0.43, 95% CI: 0.19-0.98) were less likely to be tested.

CONCLUSIONS

In this population, partner testing among HSV-2 seronegative women was feasible which supports further study to determine if identification of partners who pose a potential risk of HSV infection during pregnancy is an effective approach to reduce HSV acquisition in pregnant women.

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.

Maternal herpes simplex virus antibody avidity and risk of neonatal herpes

OBJECTIVE

The objective of the study was to assess whether herpes simplex virus antibody avidity is associated with risk of transmission of herpes simplex virus to the neonate.

STUDY DESIGN

We developed a novel herpes simplex virus type 1 avidity test based on the commercially available Focus HerpeSelect-1 enzyme-linked immunosorbent assay kit using sera from nonpregnant subjects with genital herpes simplex virus-1 infection. We used this test, and the previously developed herpes simplex virus type 2 avidity test, to compare maternal herpes simplex virus-1 and herpes simplex virus-2 antibody avidity in women who transmitted herpes simplex virus to the neonate and women who had herpes simplex virus isolated from genital secretions at delivery but who did not transmit herpes simplex virus to their infants.

RESULTS

Among nonpregnant subjects with genital herpes simplex virus-1 infection whose sera were used to develop the herpes simplex virus-1 avidity test, a significant relationship between herpes simplex virus-1 antibody avidity and time since herpes simplex virus-1 acquisition was observed (P < .001, mixed-effects model), with median avidity values increasing over time after primary infection. Among pregnant, herpes simplex virus-1, or herpes simplex virus-2 seropositive women, 4 of 8 women (50%) with avidity 40 or greater transmitted herpes simplex virus to the neonate, compared with only 12 of 97 (12%) of women with avidity greater than 40 (P = .02).

CONCLUSIONS

Herpes simplex virus-1 antibody avidity increased over time after genital herpes simplex virus-1 acquisition, as has been previously observed for herpes simplex virus-2. Among women with herpes simplex virus antibody at delivery, low antibody avidity was associated with herpes simplex virus transmission to the neonate and may be a useful marker for recent seroconversion.

Genital Herpes Complicating Pregnancy

Approximately 22% of pregnant women are infected with herpes simplex virus (HSV)-2, and 2% of women will acquire HSV during pregnancy. Remarkably, up to 90% of these women are undiagnosed because they are asymptomatic or have subtle symptoms attributed to other vulvovaginal disorders. Diagnosis of genital herpes relies on laboratory confirmation with culture or polymerase chain reaction assay of genital lesions and type-specific glycoprotein G-based serologic testing. Neonatal herpes is the most severe complication of genital HSV infection and is caused by contact with infected genital secretions at the time of labor. Maternal acquisition of HSV in the third trimester of pregnancy carries the highest risk of neonatal transmission. Despite advances in the diagnosis and treatment of neonatal herpes, little change in the incidence or serious sequelae from this infection has occurred. As such, prevention of the initial neonatal infection is critically important. Obstetricians are in a unique position to prevent vertical HSV transmission by identifying women with genital lesions at the time of labor for cesarean delivery, prescribing antiviral suppressive therapy as appropriate, and avoiding unnecessary invasive intrapartum procedures in women with genital herpes. Enhanced prevention strategies include identification of women at risk for HSV acquisition during pregnancy by testing women and possibly their partners for HSV antibodies and providing counseling to prevent transmission to women in late pregnancy.

Poor Correlation Between Genital Lesions and Detection of Herpes Simplex Virus in Women in Labor

OBJECTIVE

To estimate the accuracy of clinical diagnosis of genital herpes for herpes simplex virus (HSV) detection among women in labor.

METHODS

Viral detection by culture and HSV DNA polymerase chain reaction (PCR) among women who underwent cesarean delivery for genital herpes was compared with women without HSV symptoms in labor who had genital swabs collected for HSV culture and to a subset of these women who had genital specimens available for PCR analysis, regardless of culture results.

RESULTS

From 1989 to 1999, 126 of 19,568 (0.6%) women underwent cesarean delivery for HSV. Twenty-six percent of 110 of these women had HSV detected by culture from at least 1 genital specimen and 46% of 70 of these women had HSV detected by PCR. During the same period, 61 of 12,623 (0.5%) asymptomatic women had HSV detected by culture. Between 1995 and 1996, 57 of 2,109 (2.7%) asymptomatic women had HSV detected by PCR. Thus, the presence of genital lesions had a sensitivity for HSV detection of 37% by culture and 41% by PCR. The amount of HSV present in asymptomatic women with HSV detected in genital secretions by PCR was often as high as those with genital lesions, although the median amount of HSV DNA detected was greater in women with lesions.

CONCLUSION

Clinical diagnosis of genital herpes at the time of labor correlates relatively poorly with HSV detection from genital sites or lesions by culture or PCR and fails to identify asymptomatic women who have HSV in their genital secretions at the time of labor.

Cost-effectiveness of herpes simplex virus type 2 serologic testing and antiviral therapy in pregnancy

OBJECTIVE

The purpose of this study was to determine whether serologic testing for herpes simplex virus type 2 (HSV-2) in pregnant women and their partners is cost-effective.

STUDY DESIGN

A decision analysis model was developed to investigate the cost-effectiveness of providing type-specific serologic testing at week 15 of pregnancy for all women unaware of their HSV-2 status, and offering antiviral suppressive therapy from week 36 until delivery to all seropositive women. This scenario was compared with current care, in which only a minority of women diagnosed with genital herpes (GH) receives antiviral suppressive therapy (AST). In a third scenario, testing is offered to partners of pregnant women who test seronegative, and antiviral suppressive therapy is offered to the partners who test seropositive.

RESULTS

Compared with current care, offering testing and antiviral suppressive therapy to 100,000 pregnant women resulted in an incremental cost of $3.1 million, 15.7 fewer cases of neonatal herpes, 186 fewer cesarean deliveries, and an incremental cost per quality-adjusted life- year gained (QALY) of $18,680. Offering testing and suppressive therapy to both the pregnant women and their partners resulted in an increased cost of $8.6 million, 16.8 fewer cases of neonatal herpes, 192 fewer cesarean deliveries, and an incremental cost per QALY of $48,946 compared with no testing.

CONCLUSION

Compared with commonly accepted benchmarks for cost-effectiveness (<$50,000/QALY), type-specific HSV-2 serologic testing of pregnant women may be a cost-effective strategy.

Herpesviridae infections in newborns: varicella zoster virus, herpes simplex virus, and cytomegalovirus

Varicella zoster virus (VZV), herpes simplex virus (HSV) and cytomegalovirus (CMV) are all members of the Herpesviridae family.Humans are the only source of infection for these double stranded DNA viruses. Infants may acquire these infections in utero, peripartum, or postnatally, resulting in a variety of clinical syndromes, ranging from asymptomatic infection to severe infection,with high mortality rates and significant long-term morbidity. This article presents the epidemiology, clinical characteristics, treatment,and prevention strategies for VZV, HSV, and CMV infections in infants.

Neonatal herpes simplex infection

Tremendous advances have occurred over the past 30 years in the diagnosis and management of neonatal herpes simplex virus (HSV) disease. Mortality in patients with disseminated disease has decreased from 85 to 29%, and that in patients with central nervous system (CNS) disease has decreased from 50 to 4%. Morbidity has been improved more modestly: the proportion of patients with disseminated disease who are developing normally at 1 year has increased from 50 to 83%. While the proportion of patients with neurologic morbidity following CNS disease has remained essentially unchanged over the past three decades, the total number of patients who are developing normally following HSV CNS disease has increased due to the improved survival. Although additional therapeutic advances in the future are possible, more immediate methods for further improvements in outcome for patients with this potentially devastating disease lie in an enhanced awareness of neonatal HSV infection and disease. A thorough understanding of the biology and natural history of HSV in the gravid woman and the neonate provides the basis for such an index of suspicion and is provided in this article.

Current treatment options to prevent perinatal transmission of herpes simplex virus

Neonatal herpes is a potentially devastating consequence of perinatal transmission of the herpes simplex virus (HSV), with significant morbidity and mortality. Treatment options are available, but must begin early in disease with manifestations that are often protean. Thus, preventive measures need to be optimised. Antiviral suppression in late pregnancy of women with a history of recurrent genital herpes will decrease symptomatic recurrence at delivery and appears to reduce caesarian section rates. However, primary HSV Type 2 and primary HSV Type 1 episodes have the highest neonatal transmission rates and thus, effective prevention may require the identification and suppression of the discordant partner. Significant experience has been gained with the use of acyclovir in pregnancy and it is recommended for both episodic and suppressive therapy in pregnant women. Its use has been demonstrated to be cost-effective in suppressive therapy, although issues regarding compliance and the potential for neonatal neutropenia need to be addressed. The more conveniently dosed prodrugs valacyclovir and famciclovir are being evaluated for use in pregnancy.

Herpes simplex virus infections of the central nervous system

Herpes simplex virus (HSV) infections of the central nervous system (CNS) can occur within weeks after birth (neonatal HSV disease) or in childhood or adulthood [herpes simplex encephalitis (HSE)]. Most cases of neonatal HSV disease are caused by HSV type 2, whereas virtually all cases of HSE are caused by HSV type 1. Diagnostic advances made during the past decade include the application of polymerase chain reaction (PCR) technology to cerebrospinal fluid from patients with suspected HSV CNS disease to evaluate for the presence of HSV DNA. Although not foolproof, PCR is a powerful diagnostic tool that has supplanted brain biopsy as the modality of choice for diagnosing HSV CNS disease, in no small part because of the invasiveness of brain biopsy. PCR also can provide information regarding the therapeutic response to antiviral therapy. Efforts made during the past decade to improve the outcome of HSV CNS disease have focused on increased doses of intravenous acyclovir administered for longer durations of time. Although advances have been achieved, morbidity and mortality rates from neonatal HSV disease and HSE remain unacceptably high.

Herpes simplex virus type 2 and heterosexual spread of human immunodeficiency virus infection in developing countries: hypotheses and research priorities

Herpes simplex virus type 2 (HSV-2) infection is almost always sexually transmitted, and causes genital ulceration. Significant progress in our understanding of HSV infection has occurred over the last decade, in part related to the development of accurate and sensitive laboratory tests to study HSV-2. The application of PCR and type-specific serology to individual cases and in population-based studies has enabled the identification of a potentially important role for HSV-2 infection as a cofactor in the sexual transmission of HIV. This is a particular issue in developing countries. This review describes the epidemiology of HSV-2 infection in the HIV era, the hypotheses regarding HSV-HIV interactions, and research priorities for the developing world.

A double-blind, randomized, placebo-controlled trial of acyclovir in late pregnancy for the reduction of herpes simplex virus shedding and cesarean delivery

OBJECTIVE

The purpose of this study was to assess the efficacy of acyclovir in the reduction of herpes simplex virus culture and polymerase chain reaction positivity and cesarean delivery.

STUDY DESIGN

Women with recurrent genital herpes simplex virus were randomized to acyclovir 400 mg three times daily or placebo from 36 weeks of gestation until delivery. A subset of daily specimens for herpes simplex virus culture and DNA polymerase chain reaction was self-collected. Analyses used chi(2), Fisher exact, and Mann-Whitney U tests.

RESULTS

Lesions occurred at delivery among 11 of 78 women (14%) who received placebo and 4 of 84 women (5%) who received acyclovir (P =.08). Herpes simplex virus culture and polymerase chain reaction positivity near delivery occurred in 7% and 34% women in the placebo group and 0 and 2% in the acyclovir group (P =.03 and <.01, respectively). Cesarean delivery for herpes simplex virus occurred in 8 of the women (10%) in the placebo group and in 3 of the women (4%) in the acyclovir group (P =.17). Despite reductions in herpes simplex virus detection, 6% of the women who received acyclovir had herpes simplex virus detected by polymerase chain reaction on >20% of days. Neonatal outcomes were similar between groups.

CONCLUSION

Acyclovir significantly reduced, but did not eliminate, herpes simplex virus lesions and detection in late pregnancy.

Acyclovir suppression to prevent recurrent genital herpes at delivery

OBJECTIVE

To determine if suppressive acyclovir near term decreased the frequency of clinical recurrences at delivery in women with recurrent genital herpes simplex virus (HSV) infection.

METHODS

We conducted a prospective, double-blind, randomized trial in 234 women with recurrent genital herpes. Women with genital infection of any frequency were enrolled. Patients received either suppressive oral acyclovir 400 mg three times daily or an identical placebo after 36 weeks' gestation. Clinical lesions were identified, and HSV cultures were obtained at delivery. The frequencies of clinical and subclinical HSV recurrences at delivery were evaluated.

RESULTS

Six percent of patients treated with acyclovir, and 14% of patients treated with placebo had clinical HSV at delivery (p = 0.046). No patients in the acyclovir group had positive HSV cultures, compared with 6% of placebo-treated patients (p = 0.029). There was no significant difference in subclinical HSV shedding in the acyclovir group (0%) compared with the placebo-treated group (3%) (p = 0.102).

CONCLUSIONS

Suppressive acyclovir therapy significantly decreased the incidence of clinical genital herpes and the overall incidence of HSV excretion at delivery in patients with previous herpes infection.

Management of neonatal herpes simplex virus infection

Herpes simplex viruses (HSV) are ubiquitous pathogens which can be transmitted vertically causing significant morbidity and mortality in neonates. Neonatal HSV infection is infrequent with an incidence ranging from 1 in 3,500 to 1 in 20,000, depending on the population. Neonatal HSV infection is much more frequent in infants born to mothers experiencing a primary HSV infection with an incidence approaching 50%, while infants born to mothers experiencing recurrent HSV infection have an incidence of less than 3%. Neonatal infections are clinically categorised according to the extent of the disease. They are: (i) skin, eye and mouth (SEM) infections; (ii) central nervous system infection (encephalitis)--neonatal encephalitis can include SEM infections; and (iii) disseminated infection involving several organs, including the liver, lung, skin and/or adrenals. The central nervous system may also be involved in disseminated infections. Caesarean section, where the amniotic membranes are intact or have been ruptured for less than 4 hours, is recommended for those women who have clinical evidence of active herpes lesions on the cervix or vulva at the time of labour. This procedure significantly decreases the risk of transmission to the infant. Diagnosis of neonatal infection requires a very high level of clinical awareness as only a minority of mothers will have a history of genital HSV infection even though they are infected. Careful physical examination and appropriate investigations of the infant should accurately identify the infection in the majority of cases. Treatment is recommended where diagnosis is confirmed or there is a high level of suspicion. The current recommendation for treatment is aciclovir 20 mg/kg 3 times daily by intravenous infusion. Careful monitoring of hydration and renal function as well as meticulous supportive care of a very sick infant is also required. The newer anti-herpes agents, valaciclovir and famciclovir, offer no advantage over aciclovir and are not recommended for neonatal HSV infection. Prognosis is dependent upon the extent of disease and the efficacy of treatment, with highest rates of morbidity and mortality in disseminated infections, followed by central nervous system infection and the least in SEM infection. However, SEM infection is associated with poor developmental outcome even in infants who do not have encephalitis. Studies to improve the outcome of SEM infection are in progress. Neonatal HSV infections, although being relatively uncommon, are associated with significant morbidity and mortality if unrecognised and specific treatment is delayed. Diagnosis relies on a high level of clinical suspicion and appropriate investigation. With early therapy, the prognosis for this infection is considerably improved.

Acyclovir suppression to prevent clinical recurrences at delivery after first episode genital herpes in pregnancy: an open-label trial

OBJECTIVE

To continue evaluation of the use of acyclovir suppression in late pregnancy after first episode genital herpes simplex virus (HSV) infection, using an open-label study design.

METHODS

Ninety-six women diagnosed with genital herpes for the first time in the index pregnancy were prescribed suppressive acyclovir 400 mg orally three times daily from 36 weeks until delivery in an open-label fashion. Herpes cultures were obtained when patients presented for delivery. Vaginal delivery was permitted if no clinical recurrence was present; otherwise a Cesarean delivery was performed. Neonatal HSV cultures were obtained and infants were followed clinically. Rates of clinical and asymptomatic genital herpes recurrences and Cesarean delivery for genital herpes were measured, and 95% confidence intervals were calculated.

RESULTS

In 82 patients (85%) compliant with therapy, only 1% had clinical HSV recurrences at delivery. In an intent to treat analysis of the entire cohort, 4% had clinical recurrences (compared with 18-37% in historical controls). Asymptomatic shedding occurred in 1% of women without lesions at delivery. Two of the four clinical recurrences were HSV-culture positive. No significant maternal or fetal side-effects were observed.

CONCLUSIONS

In clinical practice the majority of patients are compliant with acyclovir suppression at term. The therapy appears to be effective at reducing clinical recurrences after a first episode of genital herpes complicating a pregnancy.

HSV-2 specific serology should not be offered routinely to antenatal patients

The proposal to introduce antenatal screening for HSV has no evidence for a public or individual health benefit; indeed, it has the potential to increase anxiety for patients, with a minimal likelihood of reducing the risk of neonatal herpes infection. Antenatal screening of an essentially healthy population of women must be validated in settings of different rates of neonatal HSV infection and the purposes and limitations of screening clearly outlined. Identification of pregnant women at risk of acquiring genital herpes in pregnancy is also dependent upon being able to obtain the serostatus of the male sexual partner which will reduce the practical application of the test if both patient and partners need to be screened. We recommend that efforts to improve on the currently established mechanisms for reducing the morbidity of neonatal herpes, namely early diagnosis and prompt treatment, must take priority for resources over new and unevaluated screening programmes, such as routine testing of antenatal patients.

Viremia in neonatal herpes simplex virus infections

BACKGROUND

Polymerase chain reaction assays of the peripheral blood mononuclear cells (PBMC) and plasma may facilitate the diagnosis of neonatal herpes simplex virus (HSV).

METHODS

Assays for HSV DNA were submitted from at least 1 specimen site (PBMC, plasma or cerebrospinal fluid) in 11 consecutive cases of neonatal HSV infection.

RESULTS

HSV DNA was detected by PCR in the PBMC of 6 of 10 infants tested (60%), the plasma of 4 of 6 tested (67%) and the cerebrospinal fluid of 4 of 11 tested (36%).

CONCLUSIONS

HSV viremia is more frequent than previously appreciated, and detection of HSV DNA in PBMC and plasma is a useful diagnostic tool, particularly in infants without skin lesions.

Serological evaluation of herpes simplex virus type 1 and type 2 infections in pregnancy

OBJECTIVE

Serological evaluation of herpes simplex virus infections during pregnancy.

METHODS

2991 serum samples were obtained during 1st, 2nd, and 3rd trimester from 997 pregnant women. Baculovirus expressed glycoproteins gG1 (HSV-1) and gG2 (HSV-2) were used as antigens in ELISA for HSV-1 and HSV-2 IgG and IgA antibodies.

RESULTS

The prevalence of HSV-1 gG1 antibodies was 70% and that of HSV-2 gG2 antibodies 16%. Among susceptible women we found five (0.6%) cases with serological evidence of primary HSV-2 infection during pregnancy. Evidence of active HSV-1 infection was found in nine (0.9%) cases. Decline of HSV-2 gG2 IgG antibody levels during pregnancy was pronounced compared with HSV-1 gG1 IgG antibody levels (p < 0.01); also the proportion of seroreversions was considerably higher among HSV-2 seropositives (25%) than among HSV-1 seropositives (3%) (p < 0.001).

CONCLUSIONS

HSV-2 gG2 IgG antibodies were readily distinguished from HSV-1 gG1 IgG antibodies by the glycoprotein gG ELISAs. Serological assays for gG2 antibodies should guard against the decline of specific antibodies during pregnancy.

Prevention of perinatal herpes: prophylactic antiviral therapy?

So what is the take-home message from these studies? The first question, about fetal and neonatal safety, appears to be answered positively. With more than 1,812 infants reported to have been exposed to varying amounts and duration of maternal acyclovir suppression, there has not been any apparent, short-term adverse fetal or neonatal effect. Use of acyclovir in infants, even in those that are premature, is very well tolerated, with a wide margin of safety. In addition, the pharmacokinetics studies by Frenkel et al and Kimberlin et al, as well as the animal studies, suggest that maternal use of acyclovir may actually provide a prophylactic and therapeutic benefit to an infant who is exposed to HSV. The second question, as to whether acyclovir suppression would simply change symptomatic outbreaks into asymptomatic ones, also appears to have some answers. The information provided by Wald et al indicated that acyclovir suppression actually decreases asymptomatic shedding, along with decreasing clinical recurrences. Because asymptomatic shedding seems to be similar in pregnant and nonpregnant patients, it would be reasonable to assume that asymptomatic shedding also would be decreased at delivery in pregnant women with HSV infection. This supposition is supported by the data from the randomized trials and cohort studies that demonstrated a lower than expected asymptomatic shedding rate. As yet, however, there has been no randomized trial in pregnant women that has had an adequate sample size to confirm this on a statistically significant basis. The third question, whether acyclovir suppression would lower the frequency of symptomatic recurrences at parturition, reducing the need for cesarean in these patients, has answers as well, although they may not be as clear cut as one would like. Women who experience their first genital herpes outbreak while they are pregnant seem to benefit from acyclovir suppression, with both a decrease in the risk of clinical recurrences at delivery and a decreased need for cesarean delivery. This is well documented by a randomized trial and other cohort studies. Acyclovir's efficacy in patients who have a history of genital herpes infections antedating their pregnancy is less clear. The data appear to indicate a clinically important decrease in the likelihood of symptomatic reactivations at the time of delivery, although the sample sizes in the randomized studies have been too small to draw a statistically significant conclusion one way or the other. Unfortunately, a definitive trial for this group of women may never be done. Assuming a 13% recurrence risk at the time of delivery and a 50% decrease in recurrences with the use of acyclovir, 652 women would have to complete the study to achieve a power of 80%. Conducting the study at the largest, single institution, prenatal center in the United States, Scott et al were only able to enroll 222 women during a period of 6 years. Likewise, Brocklehurst et al terminated their trial early because of recruitment difficulties. They enrolled only 63 women during a period of 4 years using two different sites in the United Kingdom. Unless a multicenter trial is conducted or a meta-analysis performed on the available data, we will probably have to be content with the data as it now stands. With valacyclovir and famciclovir now available, it is unlikely that any further work will be done with acyclovir. Information from the valacyclovir trials, however, may reach statistical significance because of changes in the study design that will allow smaller sample sizes to reach adequate power. Famciclovir treatment holds promise because of its longer intracellular half-life, but until concerns about potential mutagenicity are resolved and more information on its efficacy for suppressive therapy becomes available, it should not be considered for maternal suppressive therapy. Acyclovir appears to be effective, at least in some cohorts, and is probably safe for the fetus. (AB

Do antepartum herpes simplex virus cultures predict intrapartum shedding for pregnant women with recurrent disease?

OBJECTIVE

To examine antenatal screening as a predictor of intrapartum shedding of herpes simplex virus (HSV) and to determine its usefulness in guiding the appropriate route of delivery for patients with recurrent HSV in pregnancy.

METHODS

A population of 198 pregnant women with a history of recurrent genital HSV were cultured in the last weeks of their pregnancy by specially-trained personnel and intrapartum by their delivering attendants.

RESULTS

Of cultures from a total of 906 antenatal visits, 17% were culture positive, with an asymptomatic shedding rate of 3.4%. Asymptomatic shedding occurred in 12.6% of women. Over the 8-week antepartum period, viral culture-positivity rates for each visit ranged from 11% to 19.5%. This provided an expected delivery culture-positivity rate of 15.3%. However, actual intrapartum viral culture positivity occurred in only three of 191 women (1.5%; P < 0.001). Because previous studies have suggested antepartum culture positivity fails to predict intrapartum viral shedding, evaluations, including cultures, as well as predictive values for subsequent culture positivities, were determined under the supervision of an infectious disease specialist. Under these conditions, positive predictive values were 59% when the interval between visits was 2 days, but only 19% when days between visits were >2 (P < 0.0001). No cases of neonatal herpes were seen in this population, although cesarean deliveries were performed in 31% of the patient population, with genital herpes as the indication for 56% of those.

CONCLUSIONS

Antepartum serial screening by viral culture is not predictive of an infant's risk of intrapartum viral exposure when conducted at weekly intervals. However, more frequent assessments of patients can be predictive of an infant's exposure risk to HSV; for patients with frequent recurrent disease near term or primary infection in pregnancy, frequent late antepartum screening may be appropriate.

Herpes simplex virus

Herpes simplex virus (HSV) infection is prevalent worldwide. Herpes labialis, caused predominantly by HSV-1, and herpes vulvovaginitis, caused predominantly by HSV-2, may result in significant morbidity and mortality for infected neonates exposed during delivery. The diagnosis of HSV infection is made by serological testing, viral culture, or polymerase chain reaction. Women with primary herpes vulvovaginitis exhibit a painful vesicular rash which is self-limited but may be followed by multiple recurrences. Women at greatest risk to transmit HSV to their neonates are those who experience their first episode of HSV during the latter stage of pregnancy. If infected, their neonates may have localized skin, eye and mucosal lesions, invasive central nervous system infection, or disseminated disease. Because of the potentially devastating outcome for a baby infected with HSV, pregnant women with active HSV lesions at delivery should be offered a cesarean section. Still, many neonates who are infected with HSV are born to women with asymptomatic HSV shedding. Therefore, prevention of HSV during pregnancy is exceedingly important.

Herpes simplex encephalitis: a review

Patients with herpes simplex encephalitis generally have altered mental function and are rarely able to provide a good medical history. Failure to diagnose this serious disease may result in permanent neurologic damage or death of the patient. Rapid institution of newer diagnostic tests such as polymerase chain reaction for herpes simplex virus is essential for proper diagnosis. Parenteral acyclovir therapy is efficacious but, clearly, improvements in prevention and therapy are still important research goals. This review is meant to inform physicians and nurses concerning the current diagnosis and management of this treatable but potentially fatal illness.