1: Infections in pregnant women

Some infections are more serious in pregnant than non-pregnant women because of the potential for vertical transmission to the fetus or infant (eg, varicella, rubella, cytomegalovirus infection, toxoplasmosis and listeriosis). Pre-pregnancy or routine antenatal screening for presence of, or susceptibility to, some of these infections and appropriate management can prevent adverse fetal or perinatal outcomes; screening should include rubella IgG, hepatitis B surface antigen, serological tests for syphilis and HIV antibody. If certain other vertically transmissible infections are suspected because of a positive antenatal test result, confirmatory tests for maternal and, if indicated, fetal infection are essential before intervention is considered (eg, cytomegalovirus infection). For some vertically transmissible infections that are not readily preventable, appropriate management of maternal infection can reduce fetal damage (eg, toxoplasmosis).

Serum concentrations, efficacy, and safety of a new, intravenously administered varicella zoster immune globulin in pregnant women

Chickenpox is teratogenic in humans, and varicella zoster immune globulin (VZIG) is given to pregnant women believed to be susceptible to the virus after contact with chickenpox. Available VZIG is given as intramuscular injections. The objective of this study was to evaluate the efficacy, safety, and serum concentrations of a new VZIG that can be given intravenously. The new VZIG (Cangene Pharm., Inc.) was compared to the standard VZIG (Massachusetts Public Health Biologic Laboratories) in a randomized protocol in 57 pregnant women seronegative to varicella zoster virus (VZV). Pregnant women received 125 units per 10 kg body weight to a maximal dose of 625 units. Women were evaluated on days 2, 7, 14, and 28 and at other times if symptoms developed into clinical varicella, which was scored by the Constitutional Illness Score. The new VZIG was comparable to the standard VZIG on all parameters of efficacy and safety. Levels of VZV antibodies at day 2 postinjection were significantly higher among those receiving the new preparation intravenously. The authors concluded that the new intravenous form of VZIG confers higher initial levels of VZV antibodies and is comparable in terms of its maternal efficacy and safety to the standard form of VZIG.

Varicella vaccination in children with steroid-sensitive nephrotic syndrome

We have studied serological and clinical response to live, attenuated varicella zoster virus (VZV) vaccine (Varilrix, SmithKline Beecham) in 20 patients with steroid-sensitive nephrotic syndrome (SSNS) in remission and 22 normal controls who had no history of varicella and no detectable antibody to VZV. Nephrotic patients included 15 boys and 5 girls, with a mean age of 4.7 years (range 2-11.4 years). The controls were healthy age-matched children (13 girls and 9 boys). Seventeen patients with SSNS (85%) and 19 healthy controls (86%) seroconverted 8 weeks after vaccination. One patient with SSNS had a relapse 20 days after vaccination, and 1 child in the control group had a rash. Two years after vaccination, antibodies to VZV were detected in 12 of 17 responders, 2 of 3 non-responders, and 13 of 22 controls. Within 2 years of vaccination, 3 of the vaccine responder children with SSNS had a mild varicella infection. Two responder and 1 non-responder nephrotic children and 9 controls were lost to long-term follow-up. Our results show that immunization with a single dose of VZV vaccine is safe and effective in children with SSNS in remission.

Impact of vaccine cost and information about complications of varicella on parental decision regarding varicella vaccine

BACKGROUND

The influence of providing information about complications of disease and vaccine cost on parental decision to vaccinate against varicella was assessed.

METHOD

During telephone interviews of 330 parents of infants aged 9 months, parents were asked if they would agree to have their child vaccinated and were presented information first about varicella complications and then about cost of the vaccine.

RESULTS

When complications were explained but information about cost was not, 94% of parents were favourable toward having their child vaccinated. When complications were not explained but cost was presented, this percentage was only 34%. When both cost and complications were presented, 60% of parents were favourable toward the vaccine.

INTERPRETATION

In improving receptivity towards varicella vaccine, parents should always be presented data regarding varicella complications by their health care provider.

Immunogenicity of a recombinant varicella-zoster virus gE-IE63 fusion protein, a putative vaccine candidate against primary infection and zoster reactivation

The varicella-zoster virus (VZV) envelope glycoprotein E (gE) and immediate early protein 63 (IE63) are well known targets for specific humoral and cell-mediated immune responses during VZV infection and latency, respectively. The present study evaluated the immunogenicity of an engineered chimeric recombinant gE-IE63 (recgE-IE63) protein secreted from CHO cells, wherein a soluble form of gE, deleted of its anchor and cytoplasmic domains was fused to IE63. Guinea pig vaccinations with adjuvanted recgE-IE63 elicited a strong and specific humoral immune response directed to each counterpart. Sera from recgE-IE63-immunized animals neutralized cell-free VZV. This neutralizing capacity was dependent only on the recgE moiety as serum depletions on recgE-immobilized sepharose totally abolished VZV neutralization. The cell-mediated immune response induced by recgE-IE63 was evaluated in lymphoproliferation assays. An antigen-specific proliferative response was demonstrated after lymphocyte stimulation with recIE63 but not with recgE. We conclude that recombinant chimeric recgE-IE63 induced both humoral and cell-mediated immune responses and thus could constitute a putative subunit vaccine candidate against VZV primary infection and zoster reactivation.

Varicella disease after introduction of varicella vaccine in the United States, 1995-2000

CONTEXT

Before licensure of varicella vaccine in 1995, varicella was a universal childhood disease in the United States, causing 4 million cases, 11,000 hospitalizations, and 100 deaths every year.

OBJECTIVE

To examine population-based disease surveillance data in 3 communities to document the impact of the varicella vaccination program.

DESIGN, SETTING, AND SUBJECTS

Active surveillance for varicella conducted among the populations of Antelope Valley, Calif; Travis County, Tex; and West Philadelphia, Pa; from January 1, 1995, to December 31, 2000. Reporting sites included child care centers, schools, universities, physicians, public health clinics, hospitals, emergency departments, and households.

MAIN OUTCOME MEASURES

Trends in number and rate of varicella cases and hospitalizations; varicella vaccine coverage.

RESULTS

From 1995 through 1998, in each surveillance area, the number of verified varicella cases varied from year to year with marked springtime seasonality. In 1999, the number and rates of varicella cases and hospitalizations declined markedly. From 1995 through 2000, in Antelope Valley, Travis County, and West Philadelphia, varicella cases declined 71%, 84%, and 79%, respectively. Cases declined to the greatest extent among children aged 1 to 4 years, but cases declined in all age groups, including infants and adults. In the combined 3 surveillance areas, hospitalizations due to varicella declined from a range of 2.7 to 4.2 per 100,000 population in 1995 through 1998 to 0.6 and 1.5 per 100,000 population in 1999 and 2000, respectively (P =.15). By 2000, vaccine coverage among children aged 19 to 35 months was 82.1%, 73.6%, and 83.8% in Los Angeles County, Texas, and Philadelphia County, respectively.

CONCLUSIONS

Varicella disease has declined dramatically in surveillance areas with moderate vaccine coverage. Continued implementation of existing vaccine policies should lead to further reductions of varicella disease in these communities and throughout the United States.

[Cerebellitis in the course of varicella in a child: case report]

A case of cerebellitis as a complication of varicella in a 5-year old child was described. Special attention was paid to severe course of the disease and therapeutic problems. Actually available possibilities of active and passive prophylaxis of varicella-zoster virus infections were also discussed.

The cost-effectiveness of varicella vaccination in Canada

A deterministic realistic age-structured model was used to predict the impact of vaccination on the incidence of varicella and zoster. Unit costs, estimated from literature, were applied to the predicted health outcomes. Various vaccination programs were investigated and a sensitivity analysis was performed. Assuming no impact of vaccination on zoster, varicella vaccination is estimated to cost 45,000 dollars, 51,000 dollars and 18,000 dollars per life-year gained from the health payer's perspective for infant, infant with catch-up campaign, and preteen programs, respectively. From the societal perspective, mass infant varicella vaccination was estimated to be highly cost saving in Canada. Importantly, infant varicella vaccination could result in a short- to medium-term increase of zoster incidence and thus cause vaccination to be highly cost-ineffective (118,000 dollars per life-year gained) under the health payer's perspective. From a health payer's perspective the preteen vaccination is the only strategy that is deemed cost-effective. The cost-effectiveness of infant vaccination rests heavily on the unknown relationship between varicella and zoster.

Antiviral therapy for varicella and herpes zoster

Varicella-zoster virus (VZV) causes 2 clinical illnesses, varicella (chickenpox) and herpes zoster (shingles). The purpose of this review is to describe the role of antiviral therapy in the treatment of VZV infections in healthy and immunocompromised children. Acyclovir is the drug of choice for varicella and herpes zoster. The route of administration may be intravenous or oral, depending on the immunocompetence of the host. The clinical impact of acyclovir therapy is related directly to its use early in the clinical course and to the likely susceptibility of the patient to severe or life-threatening VZV infection. Patients who have the most clinical benefit are otherwise healthy adolescents with varicella infection and high-risk populations of immunocompromised children who have varicella or herpes zoster. The morbidity and mortality of VZV infections are reduced substantially by initiating acyclovir treatment early in the course of the disease.

[Chickenpox during pregnancy]

Chickenpox during pregnancy is very uncommon and is known to cause fatal malformation during the first half of pregnancy. The infection during pregnancy is also associated with maternal morbidity and mortality. Furthermore, there may also be neonatal complications. Thus, any pregnant woman with Varicella infection should be hospitalized and followed-up closely. In this review, we examined the literature on Varicella Zoster during pregnancy with regard to prevalence, prenatal diagnosis, management and prevention.

Vaccines against persistent DNA virus infections

Persistent viruses present some particular problems for vaccine design. As for acute non-persistent viruses, the prime goal of a vaccine should be to prevent primary infection. Vaccines might also be used to modify the course of established persistent virus infections - so-called postinfective immunisation. This chapter deals with selected persistent DNA viruses, in particular the human herpes viruses.

Varicella vaccination during early pregnancy: a cause of in utero miliary fetal tissue calcifications and hydrops?

BACKGROUND

It is the purpose of this article to describe a suspected association of inadvertent vaccination with varicella vaccine during early pregnancy with the subsequent development of in utero miliary fetal tissue calcifications and fetal hydrops detected by sonogram at 15 weeks of gestation.

CASE

This is a case presentation of a pregnant patient who received varicella vaccination during the same menstrual cycle that she became pregnant, and is supplemented by a literary review. The fetus developed miliary fetal tissue calcifications and fetal hydrops detected by a targeted sonogram at 15 weeks gestation.

CONCLUSION

Varicella vaccination during early pregnancy may be a cause of miliary fetal tissue calcifications and fetal hydrops.

Neonatal varicella

Neonatal varicella is mostly caused by maternal chickenpox acquired during the last 3 weeks of pregnancy. Transplacentally transmitted infections occur in the first 10 to 12 days of life, whereas chickenpox after that time is most likely acquired by postnatal infection. If the mother develops rash between days 4 and 5 antepartum to day 2 postpartum, generalized neonatal varicella leading to death occurs in up to 20% of affected cases. Neonatal chickenpox within the first 4 days after birth has usually been found to be mild. A fatal outcome has been reported in 23% of cases if neonatal chickenpox occurs between 5 and 10 to 12 days of age. Serological methods have been widely used to confirm clinical diagnosis. For rapid virological diagnostics, amplification of viral DNA in skin swabs by polymerase chain reaction is the method of choice. To prevent severe neonatal chickenpox, passive immunization is indicated. If varicella occurs, acyclovir treatment has to be administered promptly.

Simultaneous administration of varicella vaccine and other recommended childhood vaccines--United States, 1995-1999

Live attenuated varicella vaccine (Var) is recommended in the United States for children aged 12-18 months and for susceptible older children, adolescents, and adults. The Advisory Committee on Immunization Practices recommends that Var be administered either simultaneously with measles-mumps-rubella (MMR) vaccine or separately by > or =30 days. This report summarizes an evaluation of these recommendations, which found that a decrease in Var effectiveness occurred when Var was administered <30 days after MMR; therefore, as currently recommended, physicians should administer Var simultaneously with MMR or wait at least 30 days if the vaccines are administered separately.

[Epidemiological analysis of immunity against vaccine-preventable diseases: rubella, measles, mumps and chickenpox]

BACKGROUND AND OBJECTIVE

Measles, mumps, rubella and varicella zoster virus (VZV) infections are regarded as typical diseases of childhood: They are normally clinically mild and result in lifelong immunity. Severe clinical disease is known in immunocompromised patients; rubella virus infections during pregnancy often result in congenital rubella syndrome. All these diseases are preventable by vaccination which is recommended in Germany, recently vaccination against VZV for teenager without immunity since July 2001. In the following study we screened for immunity against the four viruses.

PATIENTS AND METHODS

Serum samples were obtained at the Institute of Medical Virology Frankfurt/Main from January 1999 until December 2000. We tested for specific antibodies against measles (n = 915), against mumps (n = 857), against rubella (n = 1886) and against VZV (n = 2291). Seroprevalences were determined in different age groups.

RESULTS

Altogether the highest rate of seronegatives is detected in younger children. VZV-seronegativity rates decrease from 74 % to 32 % in younger children. Against rubella also in this age group rate of seronegatives is found in 40 % and less than 10 % by teenagers. From this age group also immunity against rubella is found approximately in 80 % of seropositives.

CONCLUSIONS

The following study shows that high seronegative rates are detectable, and here specially against VZV-specific antibodies. For seronegative teenagers, vaccination against VZV is now recommended in Germany. Immunization rates of at least 95 % in childhood would be effective in avoiding severe courses of disease and giving protection in pregnancy.

Epidemiology of primary varicella hospitalizations in Spain

An approach to the burden of varicella can be obtained from information on the hospitalizations. Data were obtained from the national surveillance system for hospital data. All hospital discharges for varicella were analyzed for the 1995-1998 period. A total of 3632 primary varicella-related discharges were identified, representing an annual incidence of 2.8 per 100,000 population. A total of 58% of cases were <10 years of age and 33% were 21-50 years old. Each year primary varicella will be responsible for 6174 days of hospitalization, representing an annual cost of 1.6 million euros. There is substantial severe morbidity each year from varicella that, to reduce, would require vaccination of infants and susceptible adults.

Deaths from chickenpox in England and Wales 1995-7: analysis of routine mortality data

OBJECTIVE

To evaluate the epidemiology and impact of mortality from chickenpox in England and Wales.

DESIGN

Review of death certificates from the Office for National Statistics on which codes for "chickenpox" or "varicella" were mentioned. Further information ascertained from certifying physician.

PARTICIPANTS

Those certified as having died from chickenpox in England and Wales, 1995-7.

MAIN OUTCOME MEASURES

Diagnosis and age and sex distributions of deaths from chickenpox.

RESULTS

On average, 25 people a year die from chickenpox. Overall case fatality was 9.22 per 100 000 consultations for chickenpox. Adults accounted for 81% of deaths and 19% of consultations. Deaths were twice as common in men as in women. More of those who died were born outside United Kingdom than expected (12% v 4%).

CONCLUSIONS

Chickenpox is not a mild disease. Deaths in adults are increasing, both in number and proportion.

Varicella zoster virus. Recent advances in management

OBJECTIVE

To provide an update on strategies for managing varicella zoster virus (VZV) and for preventing and treating established postherpetic neuralgia (PHN).

QUALITY OF EVIDENCE

Treatment guidelines are based on randomized clinical trials. Recommendations concerning other aspects of VZV management (e.g., vaccination) are based mainly on expert opinion.

MAIN MESSAGE

Varicella and herpes zoster caused by VZV can give rise to serious morbidity and mortality and should be treated. For preventing chickenpox, safe and effective immunization is widely recommended. Treating varicella-exposed seronegative pregnant women requires special attention because the virus can harm expectant mothers, fetuses, and newborns. The antiviral drugs, acyclovir, valacyclovir, and famciclovir, have been approved for treating herpes zoster and have a role in reducing the duration of PHN. Established PHN can be managed with analgesics, tricyclic antidepressants, and other agents.

CONCLUSION

Vaccination and antiviral and other systemic agents can substantially reduce the morbidity associated with VZV infection.

Vaccination to prevent varicella and shingles

Vaccination of healthy children against varicella using the live attenuated Oka vaccine has been available in Japan and south Korea for several years. In 1996, a programme of universal vaccination of children to prevent varicella was introduced in the USA and other countries, including Canada, Germany, and Sweden, have licensed the vaccine for use in healthy children. This article reviews the origin of the Oka vaccine and the evidence for vaccine safety and efficacy in children and adults. Universal vaccination of children and targeted vaccination of groups at risk of severe varicella are discussed. The possible use of the Oka vaccine to prevent zoster is reviewed, and initiatives to develop new varicella zoster virus vaccines are outlined.