Congenital varicella syndrome: the evidence for secondary prevention with varicella-zoster immune globulin

Neonatal varicella

Primary infection with varicella zoster virus (VZV) in the final 3 weeks of pregnancy may cause transplacental infection and neonatal varicella. Infants are most at risk of severe disease if born from 5 days before to 2 days after onset of the maternal varicella rash. Administration of post-exposure prophylaxis with varicella zoster immunoglobulin and treatment of varicella with aciclovir for those at highest risk of progression to severe disease is advised. Universal vaccination against VZV significantly reduces the incidence of neonatal varicella.

Seroprevalence of VZV and HSV-2 Antibodies among Women of Childbearing Age Referring to Health Centres of Mashhad, Iran: The Need for Consideration of VZV Vaccination Program

Background

Infections with herpes simplex virus type 2 (HSV-2) and varicella-zoster virus (VZV) are associated with serious maternal and neonatal health consequences. The literature review reveals a research gap regarding the seroprevalence of HSV-2 and VZV among women of reproductive age in Mashhad, Northeast of Iran. The present study aims to evaluate the seroprevalence of these viruses among a group of women in Mashhad, Iran.

Methods

Sera were collected by health center personnel using a cluster sampling method from healthy women with specific age characteristics residing in three distinct socioeconomic regions of the city. The participants, aged 20-35, were divided into three groups (20-25, 26-30, and 31-35 years). The levels of VZV and HSV-2 IgG antibodies were evaluated using commercial ELISA kits. Subsequently, the results were analyzed using SPSS software.

Results

A total of 93 women were included in the study. Anti-HSV-2 IgG antibody was detected in 3 out of 93 participants (7.5%), while anti-VZV IgG antibody was found positive in 80 out of 93 individuals (83.3%). The HSV-2 positive cases were concurrently positive for the VZV antibody. There was no significant difference in the positivity of anti-HSV-2 and anti-VZV antibody positivity within age groups or socioeconomic status (P > 0.05).

Conclusions

The high seroprevalence of VZV among nonvaccinated participants indicates a widespread presence of the virus and underscores its potentially serious impact on community health. Therefore, it is recommended that a VZV vaccination program be considered by the health system. Furthermore, the reactivation of latent HSV-2, whether symptomatic or asymptomatic, during pregnancy should not be disregarded as a life-threatening threat.

Varicella-Zoster Virus Prevalence among Pregnant Women: A European Epidemiological Review

Europe has faced a massive spread of the varicella-zoster virus through the years. Since the introduction of an effective vaccine, complications and severe forms of chickenpox have been restricted. Nevertheless, among the population, some categories need specific care, such as pregnant women, who present one of the most fragile conditions facing this infection, both for the mother and the fetus. In this review, we highlight how the varicella-zoster virus can be dangerous during pregnancy, underlining the problem of treatment and vaccination, and collect information about the European epidemiology among this particular category of women.

Congenital and Perinatal Varicella Infections

Varicella-zoster virus (VZV) is a human pathogen of the α-herpesvirus family. Some fetuses infected in utero around 8-20 weeks of pregnancy show signs of congenital varicella syndrome (CVS). Infants born to mothers who develop varicella within 5 days before and 2 days after delivery can experience severe disease with increased mortality. The best diagnostic modality is polymerase chain reaction (PCR), which can be done using vesicular swabs or scrapings, scabs from crusted lesions, tissue from biopsy samples, and cerebrospinal fluid. The prevention and management of varicella infections include vaccination, anti-VZV immunoglobulin, and specific antiviral drugs. In this article, we have reviewed the characteristics of VZV, clinical manifestations, management of perinatal infections, and short- and long-term prognosis.

Varicella Zoster in pregnancy

Chickenpox during pregnancy can cause serious complications for both mother and fetus. This includes varicella pneumonia in the mother, fetal varicella syndrome and varicella of newborn. Primary prevention includes vaccination against varicella infection and is part of standard childhood immunisation programme in many countries. Timely post-exposure prophylaxis of susceptible pregnant women with varicella zoster immunoglobulin is key to preventing chickenpox during pregnancy and its adverse fetomaternal sequelae. Antiviral therapy and appropriate supportive treatment improve maternal and neonatal outcomes.

Maternal infections

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

Varicella zoster immune globulin (VARIZIG) administration up to 10 days after varicella exposure in pregnant women, immunocompromised participants, and infants: Varicella outcomes and safety results from a large, open-label, expanded-access program

Introduction

Despite vaccination, there were more than 100,000 annual cases of varicella in the United States in 2013–2014. Individuals at highest risk of developing severe or complicated varicella include immunocompromised people, preterm infants, and pregnant women. Varicella zoster immune globulin (human) (VARIZIG) is recommended by the CDC for postexposure prophylaxis to prevent or attenuate varicella-zoster virus infection in high-risk individuals. Contemporary information on administration of VARIZIG is limited.

Methods

This open-label, expanded-access program provided VARIZIG to physician-identified, high-risk participants exposed to varicella. Participants included immunocompromised children/adults, infants (preterm, newborns whose mothers had varicella onset within 5 days before or 2 days after delivery, and those aged <1 year), and pregnant women. VARIZIG (125 IU/10 kg [up to 625 IU]) was administered intramuscularly, ideally within 96 hours, but up to 10 days, postexposure. Incidence of varicella rash and severity (>100 pox, pneumonia, or encephalitis) were assessed up to 42 days after administration.

Results

The varicella outcome population (n = 507) included 263 immunocompromised participants (32 adults, 231 children), 137 pregnant women, 105 infants, and 2 healthy adults with no history of varicella. Varicella incidence was 4.5% in immunocompromised participants, 7.3% in pregnant women, and 11.5% in infants. The incidence of varicella was similar when comparing VARIZIG administration ≤ 96 hours vs > 96 hours (up to 10 days) postexposure in the entire population (6.2% vs. 9.4%, respectively), and also in each subgroup. Of 34 participants with varicella, 5 developed > 100 pox and 1 developed pneumonia and encephalitis. There were no product-related deaths and only 1 serious adverse event (serum sickness) considered probably related to VARIZIG.

Conclusion

Postexposure administration of VARIZIG was associated with low rates of varicella in high-risk participants, regardless of when administered within 10 days postexposure. VARIZIG was well-tolerated and safe in high-risk participants.

Chickenpox: An update

Despite its benign characteristics, chickenpox is a childhood disease responsible for complications and deaths, particularly in the high-risk population. VariZIG^®, not commercialized in France, is a good alternative for seronegative individuals exposed to the virus and not eligible for vaccination. The efficacy of routine vaccination has been demonstrated with a decrease in chickenpox incidence and with the development of herd immunity. Over time, the protective antibody titer of vaccinated people decreases and can be maintained by two doses of the vaccine. A tetravalent measles-mumps-rubella-chickenpox vaccine, used in the United States, has a good tolerability in spite of the occurrence of fever and febrile seizures. Routine vaccination would contribute to make savings in France, by reducing direct and indirect costs of chickenpox.

Microbiology laboratory and the management of mother-child varicella-zoster virus infection

Varicella-zoster virus, which is responsible for varicella (chickenpox) and herpes zoster (shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella (particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times: (1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection; (2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear (atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation; (3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and (4) when the baby is born and it is necessary to confirm a diagnosis of varicella (and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn.

Congenital varicella syndrome: A systematic review

Varicella-zoster virus (VZV) is a teratogen that can cross the placenta and cause the congenital varicella syndrome (CVS), which is characterised by multi-system anomalies. There have been 130 reported cases of CVS from 1947 to 2013. The estimated incidence of CVS was 0.59% and 0.84% for women infected with VZV during the entire pregnancy and for those infected the first 20 weeks of pregnancy, respectively. Nine cases were reported at 21-27 weeks of gestation and one case was identified at 36 weeks. Herpes zoster caused CVS in two cases. Regarding treatment, varicella zoster immunoglobulin treatment, irrespective of gestational age, should be considered in addition to antiviral drugs for women who have been exposed to or infected with virus.

Management of varicella-zoster virus primary infection during pregnancy: A national survey of practice

BACKGROUND

Varicella (VZV) infection in pregnancy can result in serious outcomes: maternal pneumoniae irrespective of the term of pregnancy, and lead to congenital varicella syndrome before 18 weeks of gestation and neonatal varicella. There are between 350 and 500 cases a year in France. Until now, there have been no scientific obstetrical guidelines for clinical practice in France for VZV infection during pregnancy.

OBJECTIVES

To evaluate health care providers' knowledge and practices concerning varicella infection during pregnancy in France.

STUDY DESIGN

An anonymous survey on VZV infection was sent by e-mail to gynecologists-obstetricians and midwives. We evaluated their knowledge and practices concerning VZV transmission, maternal varicella, congenital varicella syndrome, neonatal varicella and prevention.

RESULTS

The survey was completed by 271 professionals: gynecologists (161/271; 60%) and midwives (110/271; 40%). Among 20 items, 5 were multiple choice questions. 29 correct answers were expected. Scores ranged from 6/29 to 28/29 (mean score: 17.44/29).

CONCLUSIONS

The consequences of VZV primary infection in pregnancy are poorly known. We reveal a diversity of management among practitioners in our study population, not always in accordance with the international scientific literature or with the guidelines of other countries. Health care providers should update their knowledge of varicella infection during pregnancy. The publication of national guidelines could help to achieve this objective.

Pulmonary Disorders in Pregnancy

Pregnancy is associated with some profound changes in the cardiovascular, respiratory, immune, and hematologic systems that impact the clinical presentation of respiratory disorders, their implications in pregnancy, and the decisions to treat. In addition, concerns for fetal well-being and safety of various interventions complicate the management of these disorders. In many circumstances, especially life-threatening ones, decisions are based upon a careful assessment of the risk benefit ratio rather than absolute safety of drugs and interventions. In this chapter, we review some of the common respiratory disorders that internists or obstetricians may be called upon to manage.

Advances in the treatment of varicella-zoster virus infections

Varicella-zoster virus (VZV) causes two distinct diseases, varicella (chickenpox) and shingles (herpes zoster). Chickenpox occurs subsequent to primary infection, while herpes zoster (usually associated with aging and immunosuppression) appears as a consequence of reactivation of latent virus. The major complication of shingles is postherpetic neuralgia. Vaccination strategies to prevent varicella or shingles and the current status of antivirals against VZV will be discussed in this chapter. Varivax®, a live-attenuated vaccine, is available for pediatric varicella. Zostavax® is used to boost VZV-specific cell-mediated immunity in adults older than 50 years, which results in a decrease in the burden of herpes zoster and pain related to postherpetic neuralgia. Regardless of the availability of a vaccine, new antiviral agents are necessary for treatment of VZV infections. Current drugs approved for therapy of VZV infections include nucleoside analogues that target the viral DNA polymerase and depend on the viral thymidine kinase for their activation. Novel anti-VZV drugs have recently been evaluated in clinical trials, including the bicyclic nucleoside analogue FV-100, the helicase-primase inhibitor ASP2151, and valomaciclovir (prodrug of the acyclic guanosine derivative H2G). Different candidate VZV drugs have been described in recent years. New anti-VZV drugs should be as safe as and more effective than current gold standards for the treatment of VZV, that is, acyclovir and its prodrug valacyclovir.

Varicella-zoster virus: Prevention through vaccination

Widespread use of varicella vaccine in the United States has drastically changed the epidemiology of the disease. Although chickenpox is no longer a ubiquitous childhood infection, varicella-zoster virus continues to circulate in the community and nonimmune pregnant women remain at risk. Varicella can cause severe infection in pregnant women, often complicated by viral pneumonia. Maternal varicella occurring in the first half of pregnancy can cause the rare but devastating congenital varicella syndrome, whereas infection in the late stages of pregnancy may cause neonatal varicella. The best approach to avoiding the morbidity and mortality associated with chickenpox in pregnancy is to screen and vaccinate susceptible reproductive-age women.

Fetal varicella - diagnosis, management, and outcome

Fetal varicella syndrome (FVS) is due to transplacental infection by the Varicella zoster virus following maternal infection. The risks for the fetus and neonate depend on the timing. When varicella occurs around delivery, it often leads to disseminated neonatal varicella. When varicella occurs during pregnancy, transmission can occur, but is usually asymptomatic; some infants develop zoster postnatally and a few have FVS. Before 20 weeks' gestation, FVS can occur, with an incidence of about 1%. The lesions can affect the skin, limbs, central and autonomous nervous systems, eyes, cause calcifications, and growth retardation; mortality is high. Lesions typically follow one or several nerve territories, suggesting that damage results from in utero zoster following primary fetal infection. There has been little study of prenatal diagnosis of FVS. Serial ultrasound examination can detect various anomalies, magnetic resonance imaging can be of use to investigate for microphthamia and cerebral lesions, and amniocentesis can diagnose viral transmission. Prevention strategies include vaccination and post-exposure prophylaxis with immune globulin and/or antivirals. Perspectives for treating infected fetuses in utero require further research.

Herpes zoster during pregnancy

QUESTION

One of my pregnant patients, a 32-year-old woman (gravida 2, para 1), has a flare up of herpes zoster (HZ) at the T11 to T12 dermatomes. This virus, the varicella-zoster virus, causes chickenpox, which can be teratogenic. Is this also true for HZ?

ANSWER

Herpes zoster, unlike chickenpox, is not associated with increased fetal risk. In contrast, a nonimmune woman exposed to HZ by contact might contract chickenpox.