Varicella zoster virus infection in pregnancy

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.

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.

Varicella-zoster virus (chickenpox) infection in pregnancy

Congenital varicella syndrome, maternal varicella-zoster virus pneumonia and neonatal varicella infection are associated with serious fetomaternal morbidity and, not infrequently, mortality. Vaccination against varicella-zoster virus can prevent the disease, and outbreak control limits the exposure of pregnant women to the infectious agent. Maternal varicella-zoster immunoglobulin administration before rash development, with or without antiviral medication, can modify the progression of the disease.

Seroepidemiology of varicella-zoster virus in Bangladesh

Data on the seroprevalence of antibodies protective against the varicella-zoster virus are needed to develop strategies to prevent varicella infections in Bangladesh. Of 1209 patients evaluated at referral-level health facilities in Dhaka, 943 (78%) had no known history of chickenpox and were tested by latex agglutination for the presence of varicella-zoster antibody in serum. Forty-one per cent (386) of the 943 specimens tested were negative. Seropositivity was highest among neonates (83%), declined sharply to 19% in those aged 7-12 months, and thereafter rose steadily with age until a plateau of 85% was reached after the age of 16 years. This first report of varicella-zoster antibody seroprevalence in Bangladesh suggests that, as in other tropical areas, a significant proportion of children, adolescents and adults are susceptible. Children aged from 15 months to early adolescence might be the most important group to target with the vaccine currently available. However, to ensure successful immunisation, further, population-based seroprevalence data are needed, as are an assessment of the vaccine's acceptability and the accessibility of the target population. Incomplete coverage of young children could result in delayed acquisition, and, ultimately, in more severe disease.

Varicella and pregnancy

OBJECTIVE

To appreciate the risk of embryo-foetopathy in case of maternal varicella occurring before 20 weeks of gestation, as well as the maternal complication risk (notably pulmonary) in case of maternal varicella occurring the third trimester of pregnancy.

METHOD

Over the period from January 1987 to February 1995, 20 patients were managed for maternal varicella confirmed during the pregnancy. From these observations, the authors, by studying the literature, attempt to better specify the real fetal and/or maternal complication risk in case of maternal varicella.

RESULTS

In their personal series of 20 cases, including 17 before 20 weeks of gestation, the authors have noted no embryo-foetopathy. Similarly, no maternal complication (notably pulmonary complication), has been found. Careful study of the literature allows to specify some points. In case of varicella before 20 weeks, one observes an identical frequency of spontaneous abortions, as compared to the general population and a moderated increase of the frequency of premature delivery. The risk of congenital varicella syndrome reaches about 1.3%. Finally the risk of neonatal varicella consists in a maternal infection which occurs during the perinatal period and which is source of a high perinatal morbidity. The prenatal diagnosis is based essentially and currently, on the amniocentesis with viral research by polymerase chain reaction (PCR) in the amniotic fluid, completed by a ultrasound supervision.

CONCLUSION

The occurrence of maternal varicella during the pregnancy is rare (0.7/1000) because more than 90% of women are immunized. The risk of congenital varicella syndrome is limited to the 20 first weeks and seems very weak, authorizing therapists to reassure patients presenting a varicella during their pregnancy. Nevertheless, the risk of pulmonary complications for the mother, in case of varicella during the third trimester, does exist and requires appropriated treatment.

Acyclovir for the prevention and treatment of varicella zoster in children, adolescents and pregnancy

Varicella causes a mild, self-limiting childhood disease that may reactivate years later as shingles. In immunocompromised patients with altered cell mediated immunity, and rarely in healthy individuals, varicella results in a life-threatening infection. The antiviral drug, acyclovir, substantially reduces the mortality and risk of severe disease in these groups of patients. Early commencement of acyclovir is recommended for children with both varicella and altered cell mediated immunity, newborns during the first 2 weeks of life, preterm infants in the neonatal nursery, and severe varicella or shingles (including ocular zoster) in any patient, as well as during pregnancy. Acyclovir may be considered in children with serious cardiopulmonary disease or chronic skin disorders where varicella may exacerbate the underlying disease or increase the risk of secondary bacterial sepsis. Acyclovir, however, is not recommended for healthy individuals without severe disease, as a prophylactic agent against varicella, for asthmatics receiving aerosolized or low-dose oral steroids and/or as treatment of the post-varicella syndromes. When acyclovir is prescribed it should be given intravenously to those with severe disease, those at risk of dissemination and in children younger than 2 years of age.

Varicella during pregnancy. Maternal and fetal effects

To determine the characteristics of maternal varicella at our institution, we reviewed all cases of primary varicella in pregnancy. Using a perinatal database that summarizes all obstetric admissions, we reviewed the medical records of women with varicella infections during pregnancy. Over a 5 1/2-year period, 31 pregnancies were affected by varicella infection among 11,753 deliveries. The mean age of those patients was 19.6 years, significantly different from our overall population of 25.3 years (P < .05). The racial composition of 35% Hispanic, 35% white, and 29% African American was different from that of our general population of 55% white, 38% African American, and 6% Hispanic (P = .023). The mean gestational age of the eruption of vesicles was 25 weeks. Of the 31 women, 7 had preterm labor within a week of their varicella, 3 delivered prematurely, and 3 infants had a birth weight of less than 2,700 grams. Respiratory symptoms developed in 6 women, and pneumonia developed in 4, 2 of whom required ventilatory support, 1 for 5 days, the other for 49 days. Eight women received acyclovir during gestation, and none suffered sequelae. In all, 6 infants had lesions and anomalies noted at birth, 5 possibly associated with varicella. Varicella infection is associated with a greater-than-expected level of both maternal and fetal morbidity. The fetal disease may occur due to maternal infection at any gestation and is most likely a spectrum of complications. The maternal disease appears to be worse in the latter half of pregnancy. Programs of prevention through vaccination must account for a possibly decreased level of immunity in different populations.