The varicella zoster virus vasculopathies: clinical, CSF, imaging, and virologic features

BACKGROUND

Varicella zoster virus (VZV) vasculopathy produces stroke secondary to viral infection of cerebral arteries. Not all patients have rash before cerebral ischemia or stroke. Furthermore, other vasculitides produce similar clinical features and comparable imaging, angiographic, and CSF abnormalities.

METHODS

We review our 23 published cases and 7 unpublished cases of VZV vasculopathy. All CSFs were tested for VZV DNA by PCR and anti-VZV IgG antibody and were positive for either or both.

RESULTS

Among 30 patients, rash occurred in 19 (63%), CSF pleocytosis in 20 (67%), and imaging abnormalities in 29 (97%). Angiography in 23 patients revealed abnormalities in 16 (70%). Large and small arteries were involved in 15 (50%), small arteries in 11 (37%), and large arteries in only 4 (13%) of 30 patients. Average time from rash to neurologic symptoms and signs was 4.1 months, and from neurologic symptoms and signs to CSF virologic analysis was 4.2 months. CSF of 9 (30%) patients contained VZV DNA while 28 (93%) had anti-VZV IgG antibody in CSF; in each of these patients, reduced serum/CSF ratio of VZV IgG confirmed intrathecal synthesis.

CONCLUSIONS

Rash or CSF pleocytosis is not required to diagnose varicella zoster virus (VZV) vasculopathy, whereas MRI/CT abnormalities are seen in almost all patients. Most patients had mixed large and small artery involvement. Detection of anti-VZV IgG antibody in CSF was a more sensitive indicator of VZV vasculopathy than detection of VZV DNA (p < 0.001). Determination of optimal antiviral treatment and benefit of concurrent steroid therapy awaits studies with larger case numbers.

Consequences of varicella and herpes zoster in pregnancy: prospective study of 1739 cases

In a joint prospective study in Germany and the United Kingdom between 1980 and 1993, 1373 women who had varicella and 366 who had herpes zoster during the first 36 weeks of gestation were followed up. 9 cases of congenital varicella syndrome were identified, all occurring after maternal varicella during the first 20 weeks of gestation. The highest risk (2.0%) was observed between 13-20 weeks gestation, with 7 affected infants identified among 351 pregnancies (95% CI of risk 0.8-4.1%). Only 2 cases of congenital varicella syndrome were identified among 472 pregnancies in which maternal varicella occurred before 13 weeks (observed risk 0.4%, 95% CI 0.05-1.5%). Herpes zoster in infancy was reported in 10 children whose mothers had had varicella in pregnancy. No infants with clinical evidence of intrauterine infection were born to the 366 women with herpes zoster in pregnancy (upper 95% confidence limit of estimated risk 1.0%). Varicella-zoster-specific IgM antibody was found at birth in 4 of 16 (25%) infants with clinical manifestations of intrauterine infection and persistent specific IgG antibody in 5 of 7 infants tested. The corresponding rates in asymptomatic infants whose mothers had varicella were 12% (76/615) and 7% (22/335) respectively. No serological evidence of intrauterine infection was found in infants who mothers had herpes zoster in pregnancy. In 97 pregnant women, varicella occurred after post-exposure prophylaxis with anti-varicella-zoster immunoglobulin. No cases of congenital varicella syndrome or zoster in infancy occurred in this group. Our estimates provide a sound basis for counselling women with varicella in pregnancy. Although the risk of congenital varicella syndrome is small, the outcome for the affected infant is so serious that a reliable method of prenatal diagnosis would be valuable. In the long term, prevention of maternal varicella would be an option if a safe and effective vaccine were to become routinely available.

Intrauterine infection with varicella-zoster virus after maternal varicella

We investigated the consequences of maternal infection with varicella-zoster virus in a prospective study of 43 pregnancies complicated by varicella and 14 pregnancies complicated by herpes zoster. Nine of 43 pregnant women with varicella had associated morbidity--pneumonia (4 women), death (1), premature labor (4 of 42), premature delivery (2 of 42), and herpes zoster (1). Intrauterine varicella infection was identified on the basis of clinical evidence (anomalies characteristic of the congenital varicella syndrome, acute varicella at birth, or herpes zoster in infancy) or immunologic evidence (IgM antibody to varicella-zoster in the neonatal period, persistent IgG antibody to varicella-zoster at one to two years of age, or in vitro lymphocyte proliferation in response to varicella-zoster virus antigen). The congenital varicella syndrome occurred in 1 of 11 infants of women with first-trimester varicella. Immunologic evidence of intrauterine varicella infection was present in 7 of 33 infants tested; 4 of these infants were asymptomatic. According to clinical or immunologic criteria, 8 of 33 infants had evidence of intrauterine varicella infection. These observations show that varicella during pregnancy was associated with maternal morbidity and evidence of fetal infection, but that herpes zoster was not.

Outcome after maternal varicella infection in the first 20 weeks of pregnancy

BACKGROUND

Infection with the varicella-zoster virus during pregnancy can produce an embryopathy characterized by limb hypoplasia, eye and brain damage, and skin lesions. The risk is greatest when infection occurs during the first 20 weeks of pregnancy, but the magnitude of the risk is uncertain.

METHODS

We studied 106 women with clinically diagnosed varicella infection in the first 20 weeks of pregnancy and compared the outcomes with those in 106 age-matched, nonexposed controls.

RESULTS

Among the women with varicella, there was a trend toward more elective terminations of pregnancy (14 percent, vs. 7.5 percent among the controls; P = 0.1), corresponding to a significantly higher perception of teratogenic risk (P = 0.03). The proportions of miscarriages and live births and the mean birth weights were similar in the two study groups; there were more premature births (< or = 37 weeks) among the women with varicella infection (14.3 percent vs. 5.6 percent, P = 0.05). Congenital defects occurred in four infants born to the women with varicella (varicella embryopathy, hydrocephalus, meningocele and clubfeet, and hammer toe) and two infants born to the controls (ventricular septal defect and hip dislocation). The risk of varicella embryopathy after infection in the first 20 weeks was 1.2 percent (95 percent confidence interval, 0 to 2.4 percent). When we pooled our results with those from other prospective studies, the mean risk of embryopathy after infection with varicella-zoster virus in the first trimester was 2.2 percent (95 percent confidence interval, 0 to 4.6 percent).

CONCLUSIONS

The absolute risk of embryopathy after maternal varicella infection in the first 20 weeks of pregnancy is about 2 percent.

NIH conference. Varicella-zoster virus infections. Biology, natural history, treatment, and prevention

During the last 10 years, there have been major advances in the understanding of varicella-zoster virus and the diseases it causes. The molecular biology of the virus is being unraveled with the aid of new molecular technologies. Varicella, usually a benign manifestation of primary infection, and zoster, a result of reactivation of latent virus, can cause considerable morbidity in patients with immune impairment. Antiviral drugs, especially acyclovir, ameliorate severe infections but still have little role in the treatment of most normal patients with varicella or zoster. Varicella can be prevented when necessary by patient isolation and passive prophylaxis with varicella-zoster immune globulin. An experimental live vaccine also prevents varicella, but problems regarding its virulence for immunosuppressed patients and the durability of the protective response are still being addressed.

A controlled trial of acyclovir for chickenpox in normal children

BACKGROUND

Chickenpox, the primary infection caused by the varicella-zoster virus, affects more than 3 million children a year in the United States. Although usually self-limited, chickenpox can cause prolonged discomfort and is associated with infrequent but serious complications.

METHODS

To evaluate the effectiveness of acyclovir for the treatment of chickenpox, we conducted a multicenter, double-blind, placebo-controlled study involving 815 healthy children 2 to 12 years old who contracted chickenpox. Treatment with acyclovir was begun within the first 24 hours of rash and was administered by the oral route in a dose of 20 mg per kilogram of body weight four times daily for five days.

RESULTS

The children treated with acyclovir had fewer varicella lesions than those given placebo (mean number, 294 vs 347; P less than 0.001), and a smaller proportion of them had more than 500 lesions (21 percent, as compared with 38 percent with placebo; P less than 0.001). In over 95 percent of the recipients of acyclovir no new lesions formed after day 3, whereas new lesions were forming in 20 percent of the placebo recipients on day 6 or later. The recipients of acyclovir also had accelerated progression to the crusted and healed stages, less itching, and fewer residual lesions after 28 days. In the children treated with acyclovir the duration of fever and constitutional symptoms was limited to three to four days, whereas in 20 percent of the children given placebo illness lasted more than four days. There was no significant difference between groups in the distribution of 11 disease complications (10 bacterial skin infections and 1 case of transient cerebellar ataxia). Acyclovir was well tolerated, and there was no significant difference between groups in the titers of antibodies against varicella-zoster virus.

CONCLUSIONS

Acyclovir is a safe treatment that reduces the duration and severity of chickenpox in normal children when therapy is initiated during the first 24 hours of rash. Whether treatment with acyclovir can reduce the rare, serious complications of chickenpox remains uncertain.

Infectious origins of, and molecular mimicry in, Guillain-Barré and Fisher syndromes

Guillain-Barré syndrome (GBS), characterised by limb weakness and areflexia, is the prototype of postinfectious autoimmune diseases, and Campylobacter jejuni is the most frequent antecedent pathogen. GBS subsequent to C jejuni enteritis is associated with a severe, pure motor axonal variant and IgG antibodies against GM1, GM1b, GD1a, or GalNAc-GDla, gangliosides expressed in human peripheral nerves. Lipopolysaccharides of C jejuni isolated from GBS patients have ganglioside-like epitopes. Cytomegalovirus is the most common viral antecedent infection. Patients with demyelinating GBS who have had a recent CMV infection have severe sensory deficits and anti-GM2 IgM antibody. CMV-infected fibroblasts express the GM2 epitope. Fisher syndrome (FS), characterised by ophthalmoplegia, ataxia, and areflexia, is a GBS variant associated with anti-GQ1b IgG antibody. GQ1b is enriched in the cranial nerves that innervate the extraocular muscles. Some patients develop FS after C jejuni infection, and the lipopolysaccharide present bears the GQ1b epitope. Molecular mimicry is a possible cause of GBS and FS.

Varicella-zoster virus: atypical presentations and unusual complications

Varicella-zoster virus (VZV) is the etiologic agent of varicella (primary infection) and herpes zoster (reactivation of latent infection). Although varicella is most often a relatively benign and self-limited childhood illness, the disease can be associated with a variety of serious and potentially lethal complications in both immunocompetent and immunocompromised persons. One complication of varicella that appears to be increasing in frequency is serious bacterial soft tissue infections caused by group A streptococci. Issues related to management of varicella become especially complex when varicella involves pregnant women or susceptible neonates. Herpes zoster can be associated with a variety of neurologic complications, including a syndrome of delayed contralateral hemiparesis. Neurologic complications of herpes zoster, including chronic encephalitis, occur with increased frequency in AIDS patients. VZV retinitis is a potentially sight-threatening complication that occurs in both immunocompetent and immunocompromised persons. Current knowledge regarding pathogenesis and antiviral therapy is reviewed.

The epidemiology of varicella and its complications

The automated records of over 250,000 members of a health maintenance organization were analyzed to assess the epidemiology of varicella and its complications between 1 July 1990 and 30 June 1992. All complications were verified by review of full-text medical records. The incidence rates of varicella in persons < 15 years of age were 20%-50% lower than published figures, probably reflecting underreporting. The rates in those > or = 15 years old, however, were greater than those reported for 1972-1978 (607 vs. 291/10(5) years, 15-19 years old; 175 vs. 33/10(5) years, > or = 20 years old). The rates of hospitalization for uncomplicated varicella, skin superinfections, and pneumonia in children were, respectively, 15, 11, and 4 times higher than previous estimates. Hospitalization rates for adults with pneumonia and uncomplicated varicella were > 5 times higher than prior figures. Thus, varicella in adults and varicella complications in general may be more frequent than previously estimated.

Immunodeficiency and infections in ataxia-telangiectasia

OBJECTIVE

To characterize the immunodeficiency in ataxia-telangiectasia (A-T) and to determine whether the immunodeficiency is progressive and associated with increased susceptibility to infections.

STUDY DESIGN

Records of 100 consecutive patients with A-T from the Johns Hopkins Ataxia-Telangiectasia Clinical Center (ATCC) were reviewed.

RESULTS

Immunoglobulin (Ig) deficiencies are common, affecting IgG4 in 65% of patients, IgA in 63%, IgG2 in 48%, IgE in 23%, and IgG in 18%. Lymphopenia affected 71% of patients, with reduced B-lymphocyte number in 75%, CD4 T lymphocytes in 69%, and CD8 T lymphocytes in 51%. There was no trend for increased frequency or severity of immune abnormalities with age. Recurrent upper and lower respiratory tract infections were frequent: otitis media in 46% of patients, sinusitis in 27%, bronchitis in 19%, and pneumonia in 15%. Sepsis occurred in 5 patients, in 2 patients concurrent with cancer chemotherapy. Warts affected 17% of patients, herpes simplex 8%, molluscum contagiosum 5%, candidal esophagitis 3%, and herpes zoster 2%. Uncomplicated varicella infection occurred in 44% of patients; 2 patients had more than one clinical episode. No patient had Pneumocystis jerovici pneumonia or a complication of live viral vaccine.

CONCLUSIONS

In spite of the high prevalence of laboratory immunologic abnormalities, systemic bacterial, severe viral, and opportunistic infections are uncommon in A-T. Cross-sectional analysis suggests that the immune defect is rarely progressive.

Varicella mortality: trends before vaccine licensure in the United States, 1970-1994

We examined varicella deaths in the United States during the 25 years before vaccine licensure and identified 2262 people who died with varicella as the underlying cause of death. From 1970 to 1994, varicella mortality declined, followed by an increase. Mortality rates were highest among children; however, adult varicella deaths more than doubled in number, proportion, and rate per million population. Despite declining fatality rates, in 1990-1994, adults had a risk 25 times greater and infants had a risk 4 times greater of dying from varicella than did children 1-4 years old, and most people who died of varicella were previously healthy. Varicella deaths are now preventable by vaccine. Investigation and reporting of all varicella deaths in the United States is needed to accurately document deaths due to varicella, to improve prevention efforts, and to evaluate the vaccine's impact on mortality.

An immunodeficiency disease with RAG mutations and granulomas

We describe three unrelated girls who had an immunodeficiency disease with granulomas in the skin, mucous membranes, and internal organs. All three girls had severe complications after viral infections, including B-cell lymphoma associated with Epstein-Barr virus (EBV). Other findings were hypogammaglobulinemia, a diminished number of T and B cells, and sparse thymic tissue on ultrasonography. Molecular analysis revealed that the patients were compound heterozygotes for mutations in recombination activating gene 1 or 2 (RAG1 or RAG2). In each case, both parents were heterozygous carriers of a RAG mutation. The mutations were associated with reduced function of RAG in vitro (3 to 30% of normal activity). The parents and one sibling in the three families were healthy.

The value of detecting anti-VZV IgG antibody in CSF to diagnose VZV vasculopathy

BACKGROUND

Factors that may obscure the diagnosis of varicella zoster virus (VZV) vasculopathy include the absence of rash before TIAs or stroke as well as similar clinical features and imaging, angiographic, and CSF abnormalities to those of other vasculopathies. Diagnosis relies on virologic confirmation that detects VZV DNA, anti-VZV IgG antibody, or both in the CSF.

METHODS

We reviewed our current 14 cases of patients diagnosed with VZV vasculopathy based on combined clinical, imaging, angiographic, or CSF abnormalities. All CSFs must have been tested for VZV DNA by PCR and for anti-VZV IgG antibody by enzyme immunoassay and found to be positive for either or both. Of the 14 subjects, 8 had a history of recent zoster, whereas 6 had no history of zoster rash before developing vasculopathy.

RESULTS

All 14 subjects (100%) had anti-VZV IgG antibody in their CSF, whereas only 4 (28%) had VZV DNA. The detection of anti-VZV IgG antibody in CSF was a more sensitive indicator of VZV vasculopathy than detection of VZV DNA (p < 0.001).

CONCLUSIONS

In varicella zoster virus (VZV) vasculopathy, the diagnostic value of detecting anti-VZV IgG antibody in CSF is greater than that of detecting VZV DNA. Although a positive PCR for VZV DNA in CSF is helpful, a negative PCR does not exclude the diagnosis of VZV vasculopathy. Only when the CSF is negative for both VZV DNA and anti-VZV IgG antibody can the diagnosis of VZV vasculopathy be excluded.

Invasive group A streptococcal disease in children and association with varicella-zoster virus infection. Ontario Group A Streptococcal Study Group

OBJECTIVES

To describe the incidence and clinical features of invasive group A streptococcal (GAS) disease in children in Ontario and determine the risk of invasive GAS infection following chickenpox.

METHODS

During 1992-1996, we conducted prospective, active, population-based surveillance for pediatric invasive GAS disease in Ontario, Canada (population: 11 million; 2.5 million children) and reviewed clinical and laboratory records.

RESULTS

There were 1.9 cases of invasive GAS disease per 100,000 children per year. Streptococcal toxic shock syndrome (STSS) occurred in 7% of cases and necrotizing fasciitis (NF) in 4% for incidences of.08 and.13 per 100,000 per year, respectively. Case-fatality rates were 56% for STSS, 10% for NF, and 4% overall. The presence of chronic underlying illness other than asthma was associated with death (relative risk [RR]: 11; 95% confidence interval [CI]: 2.4-45). Fifteen percent of children identified had preceding chickenpox infection, which significantly increased the risk for acquisition of invasive GAS disease (RR: 58; 95% CI: 40-85). Children with invasive GAS and recent chickenpox were more likely to have NF (RR: 6.3; 95% CI: 1.8-22.3).

CONCLUSIONS

Childhood invasive GAS disease occurs at an incidence similar to the adult population but has a lower rate of STSS and case-fatality. Chickenpox dramatically increases the risk for acquiring invasive GAS disease, and universal chickenpox vaccination could potentially prevent up to 15% of all pediatric invasive GAS disease.

Family size, childhood infections and atopic diseases. The Aberdeen WHEASE Group

BACKGROUND

This study addresses the causes of the increases in childhood asthma and allergic disease. On the basis of an observed inverse relationship between family size and allergic disease or atopy, it has been proposed that a fall in common childhood infections may have been responsible for the rise in asthma. This study was undertaken to investigate the relationships between family size and reported allergic disease and to test the hypothesis that an inverse relationship between the two is a consequence of childhood infections.

METHODS

Data had been obtained in a 1964 cross sectional survey of a random sample of Aberdeen schoolchildren aged between 10 and 14 in that year. Records of the presence or absence of asthma, eczema, or hay fever at the time of the survey and a history of measles, pertussis, varicella, rubella, and mumps before and after the age of three years were available for 2111 subjects.

RESULTS

The risks of hay fever (odds ratio 0.2, 95% CI 0.1 to 0.8) and eczema (OR 0.3, CI 0.1 to 0.7) were inversely related to having had three or more older siblings, whilst the risk of asthma (OR 0.4, CI 0.1 to 0.9) was inversely related to having had three or more younger siblings. Increasing total numbers of siblings showed a significant trend in protection against both eczema and hay fever. A weak protective effect against asthma was found for measles after the age of three (OR 0.5, CI 0.3 to 0.9) and slight increases in the risk of eczema were associated with having had rubella or pertussis and of asthma with having had varicella. The number of infections before the age of three was associated with a significant trend in the odds ratios towards increased risk of asthma (p = 0.025). There were significant trends in the odds ratios towards greater risk of eczema and hay fever with increasing exposure to rubella, mumps, and varicella. These relations between infection and atopic diseases were independent of the potential confounding factors age, sex, father's social class, and total number of siblings.

CONCLUSIONS

These data add to the accumulating evidence that membership of a large sibship confers some protection against atopic disease. This does not appear to be explained by the common childhood infections which show conflicting relationships with atopic disease, in that measles may have some protective effect against asthma but the more infections a child has had, the more likely he or she is to have atopic disease. The explanation of the sibship effect is likely to lie elsewhere and the fall in common childhood infections is unlikely to explain the rise in atopic disease.

Detection of varicella-zoster virus DNA by polymerase chain reaction in the cerebrospinal fluid of patients suffering from neurological complications associated with chicken pox or herpes zoster

The polymerase chain reaction (PCR) was used to detect varicella-zoster virus (VZV) DNA in the cerebrospinal fluid of patients with VZV infection associated with neurological symptoms. Positive results were obtained in three of five children with post-chicken pox cerebellitis and in seven of seven herpes zoster patients with neurological symptoms. The PCR thus provides a useful tool for the early diagnosis of VZV-associated neurological disease.

Decline in varicella-related hospitalizations and expenditures for children and adults after introduction of varicella vaccine in the United States

OBJECTIVE

Universal childhood immunization against varicella in the United States, first recommended in 1995, was predicted to lead to significant decreases in varicella-related hospitalization rates and corresponding charges. Previous studies have not found such effects. We studied trends in varicella-related hospitalization rates and associated charges before and after introduction of varicella vaccine.

METHODS

We examined hospitalization and charge data from the Nationwide Inpatient Sample for the years 1993-2001, representative of national hospitalization patterns for children and adults. We derived weighted estimates of population-adjusted, varicella-related hospitalization rates and inflation-adjusted, varicella-related hospital charges.

RESULTS

The annual varicella-related hospitalization rate exceeded 0.5 hospitalizations per 10,000 US population from 1993 to 1995, declined to 0.26 per 10,000 by 1999, and again halved to 0.13 per 10,000 by 2001. Hospitalization rates declined most substantially among individuals primarily targeted for vaccination (0- to 4-year-old children) but decreased among youths aged 5 to 19 years and among adults as well. Concomitantly, varicella-related hospital charges declined from 161.1 million dollars (95% confidence interval: 130.5 million dollars-191.8 million dollars) in 1993 to 66.3 million dollars (95% confidence interval: 50.9 million dollars-81.7 million dollars) in 2001 (all 2001 US dollars). Among expected primary payers, inflation-adjusted declines in varicella-related hospital discharges-related charges accrued to Medicaid, private insurance, and "other" payers (including uninsured and self-pay) but not to Medicare.

CONCLUSIONS

This national analysis indicates a clinically and statistically significant reduction in varicella-related hospitalizations for children and adults associated with childhood varicella immunization in the United States and a corresponding significant decrease in hospital charges.

Varicella zoster virus, a cause of waxing and waning vasculitis: the New England Journal of Medicine case 5-1995 revisited

A 73-year-old man developed an ill-defined fatal vasculitis involving the central nervous system. The case report was published as a clinicopathologic exercise in February 1995 in The New England Journal of Medicine. We restudied the pathologic material and found both varicella zoster virus (VZV) DNA and VZV-specific antigen, but not herpes simplex virus (HSV) or cytomegalovirus (CMV) DNA or HSV- or CMV-specific antigen, in three of the five cerebral arteries examined. The inflammatory response, disruption of the internal elastic lamina, and detection of viral antigen were patchy from one artery to another, as well as within a given artery. A search for VZV should be conducted in cases of vasculitis when both the central and peripheral nervous systems are involved, when focal narrowing is present in large arteries, when brain imaging reveals infarction in gray and white matter, both deep and superficial, and when white matter is disproportionally involved. Zosteriform rash is not required for diagnosis.

Acyclovir therapy of chickenpox in immunosuppressed children--a collaborative study

A randomized double-blind, placebo-controlled, multicenter investigation assessed the usefulness of acyclovir in the treatment of immunosuppressed children with chickenpox. Twelve patients received placebo and eight received acyclovir. If the event of clinical deterioration, patients could be removed from the study to receive acyclovir. Eighteen patients had skin lesions within 96 hours of admission to the study. Nineteen patients had malignancies. The two groups of patients were similar in age, in concomitant or preceding immunosuppressive therapy, in status of malignancy, and in presenting granulocyte and lymphocyte counts. Zoster immune globulin or plasma had been given to 50% of the placebo group but to only 25% of the acyclovir group. One patient in each group had pneumonitis at entry. Of the patients without pneumonitis at entry, five of the 11 placebo patients compared with none of the seven acyclovir patients developed pneumonitis during treatment (P = 0.054). No evidence of toxicity related to acyclovir was observed.

Lupus anticoagulant and protein S deficiency in children with postvaricella purpura fulminans or thrombosis

OBJECTIVE

The objective of this study was to determine the cause of purpura fulminans, disseminated intravascular coagulation, or thrombosis in seven children with varicella. All children were found to have a lupus anticoagulant and acquired protein S deficiency. Thrombosis in five children was associated with presumed or documented infection with streptococcus.

STUDY DESIGN

Coagulation tests included determinations of the activated partial thromboplastin time, the prothrombin time, the dilute Russell viper venom time, the prothrombin F 1 + 2 fragment, the C4b-binding protein (C4b), total and free protein S antigen, and clotting activities of factors II, V, VII, and X and of protein C and protein S. Autoantibodies to phospholipids, cardiolipin, and protein S were determined in enzyme-linked immunosorbent assays.

RESULTS

All children had a lupus anticoagulant and acquired protein S deficiency. Thrombosis in five children was associated with presumed or documented infection with streptococcus. All children transiently expressed free protein S deficiency, elevated levels of IgG, IgM, or both binding to protein S, the lupus anticoagulant, and increased concentration of the F 1+2 fragment. Four children also had antiphospholipid or anticardiolipin antibodies. In one child a purified IgG fraction cross-reacted with both protein S and a specific varicella antigen.

CONCLUSIONS

A subset of children with varicella infection, some of whom are coinfected with streptococcus, are prone to development of a lupus anticoagulant and an autoantibody to protein S, which results in acquired free protein S deficiency. Such children are at risk of having life-threatening thrombotic events.

Theoretical epidemiologic and morbidity effects of routine varicella immunization of preschool children in the United States

The authors studied the effects of routine varicella immunization of US preschool children and of implementation of a catch-up program in older children on the age distribution of cases and on overall morbidity, with emphasis on the sensitivity of the results to level of vaccine coverage, duration of protection, responsiveness to boosting, relative residual susceptibility and infectiousness, and degree of morbidity among vaccine breakthrough cases. An age-structured theoretical transmission model was used, with values for vaccine efficacy based on a review of the literature by an expert panel. Although implementation of a vaccination program resulted in a shift in the age distribution of remaining varicella cases toward older ages with higher complication rates, the overall reduction in cases resulted in decreased morbidity as measured by overall number of hospitalizations and number of primary cases. Routine immunization with live-virus varicella vaccine would probably result in a substantial reduction in the number of uncomplicated primary cases of chickenpox, as well as a decreased number of complicated cases requiring hospitalization. The number and age distribution of vaccinated cases would depend strongly on the characteristics of the vaccine. Vaccine efficacy studies in the field should be designed to obtain better estimates of residual susceptibility, residual infectiousness, duration of protection, and effects of boosting by wild-type reinfection.

Chickenpox in pregnancy: revisited

Varicella infection during the first and second trimester of pregnancy may increase the risk for congenital varicella syndrome 0.5-1.5% above the baseline risk for major malformation. Third trimester infection may lead to maternal pneumonia which can be life threatening if not treated appropriately. Varicella-zoster immune globulin (VZIG) should be administered as soon as possible preferably within 96 h from exposure to prevent maternal infection or subsequent complications. Later than 96 h, the effectiveness of VZIG has not been evaluated. Neonatal varicella is more severe if maternal rash appears 5 days prior to or 2 days after delivery. The newborn should be given VZIG immediately. Intravenous acyclovir is recommended for maternal pneumonia and severely affected neonate. No controlled study has yet evaluated the effectiveness of acyclovir or valacyclovir for postexposure prophylaxis to pregnant women or neonates. Unlike primary varicella infection in pregnancy, herpes zoster has not been documented to cause complications unless in the disseminated form. The advent of advanced imaging techniques and molecular biotechniques has improved prenatal diagnosis. With increase use of vaccination, the incidence of chickenpox in pregnancy is expected to decline in the future.