A controlled trial of acyclovir for chickenpox in normal children

The Overview of Potential Antiviral Bioactive Compounds in Poxviruses

Poxviruses belong to the family of double-stranded DNA viruses, and it is pathogenic for humans and spread worldwide. These viruses cause infections and various diseases in human. So, it is required to develop new drugs for the treatment of smallpox or other poxvirus infections. Very few potential compounds for the treatment of poxvirus such as smallpox, chickenpox, and monkeypox have been reported. Most of the compounds has used as vaccines. Cidofovir is most commonly used as a vaccine for the treatment of poxviruses. There are no phytochemicals reported for the treatment of poxviruses. Very few phytochemicals are under investigation for the treatment of poxviruses.

Guillain-Barré syndrome following varicella-zoster virus infection: a case report and systematic review

Background

Guillain-Barré syndrome (GBS) is an acute inflammatory disease of the peripheral nervous system, rarely following Varicella-zoster virus (VZV) infection. The authors aimed to review all cases in the English literature of GBS that occurred after primary VZV infection to investigate the clinical features, diagnostic workup, treatment, and outcome of patients with GBS following VZV.

Methods

PubMed, Scopus, and Embase are systematically searched from their inception to 9 May 2022 to collect all cases of GBS following varicella-zoster infection. Patients with GBS following VZV reactivation were excluded.

Results

Among the 29 patients, the age of presentation ranged from 1.5 to 70 years with a median of 37, with a yield for males (81.5%). Most of the patients presented with sensory-motor symptoms (65.4%) and suffered from tetraparesis (81.5%). Cranial nerve palsy was present in (84%) of patients, and the seventh cranial nerve was the most commonly affected nerve (75%). Lumbar puncture showed albuminocytological dissociation in (80%) of patients. The dominant nerve conduction study subtype was acute inflammatory demyelinating polyneuropathy (65.3%). in addition, the magnetic resonance imaging showed pathological findings in only (47.5%) of the patients. Intravenous immunoglobulin is now the drug of choice for all cases of GBS following VZV infection.

Conclusion

GBS is a rare neurological complication of primary infection with VZV. However, the authors should suspect this syndrome when a patient develops ascending weakness, regardless of the absence of areflexia and albuminocytological dissociation. Drug therapy with IIVIg ensures a gradual improvement for the patient over a period of weeks to several months.

Alzheimer's disease as a viral disease: Revisiting the infectious hypothesis

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. Two major forms of the disease exist: sporadic - the causes of which have not yet been fully understood - and familial - inherited within families from generation to generation, with a clear autosomal dominant transmission of mutations in Presenilin 1 (PSEN1), 2 (PSEN2) or Amyloid Precursors Protein (APP) genes. The main hallmark of AD consists of extracellular deposits of amyloid-beta (Aβ) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein. An ever-growing body of research supports the viral infectious hypothesis of sporadic forms of AD. In particular, it has been shown that several herpes viruses (i.e., HHV-1, HHV-2, HHV-3 or varicella zoster virus, HHV-4 or Epstein Barr virus, HHV-5 or cytomegalovirus, HHV-6A and B, HHV-7), flaviviruses (i.e., Zika virus, Dengue fever virus, Japanese encephalitis virus) as well as Human Immunodeficiency Virus (HIV), hepatitis viruses (HAV, HBV, HCV, HDV, HEV), SARS-CoV2, Ljungan virus (LV), Influenza A virus and Borna disease virus, could increase the risk of AD. Here, we summarized and discussed these results. Based on these findings, significant issues for future studies are also put forward.

Creating the "Dew Drop on a Rose Petal": the Molecular Pathogenesis of Varicella-Zoster Virus Skin Lesions

Varicella-zoster virus (VZV) is a human alphaherpesvirus that causes varicella (chicken pox) as the primary infection in a susceptible host. Varicella is very contagious through its transmission by direct contact with vesicular skin lesions that contain high titers of infectious virus and respiratory droplets. While the clinical manifestations of primary VZV infection are well recognized, defining the molecular mechanisms that drive VZV pathogenesis in the naive host before adaptive antiviral immunity is induced has been a challenge due to species specificity. This review focuses on advances made in identifying the differentiated human host cells targeted by VZV to cause varicella, the processes involved in viral takeover of these heterogenous cell types, and the host cell countermeasures that typically culminate in a benign illness. This work has revealed many unexpected and multifaceted mechanisms used by VZV to achieve its high prevalence and persistence in the human population.

A Case Report of Infantile Ramsay Hunt Syndrome

Ramsay Hunt Syndrome is a rare condition in children. There are currently no internationally accepted protocols in the management of these patients. We present a case of a 9 month old child that presented to our Department with Ramsay Hunt syndrome. Included is the management of the clinical condition and a brief literature review. Early identification, a high index of suspicion and prompt treatment is required to achieve a good clinical outcome.

Acyclovir alleviates insulin resistance via activating PKM1 in diabetic mice

AIMS

Diabetes mellitus (DM) is a major global health threat characterized by insulin resistance. A new tactic to ameliorate insulin resistance, thereby reversing the exacerbation of DM, is urgently needed. The work is aiming to provide a new strategy for DM treatment as well as to identify new targets.

MAIN METHODS

C57BL/6 N mice were raised with high-fat diet (HFD) and infused with streptozotocin (STZ) to induce diabetes. The blood glucose, serum insulin, blood lipid and oxidative stress were detected. In vitro insulin resistance model experiment has been made to examine the molecular mechanisms underlying anti-diabetic effect of potential active chemicals in human hepatocellular carcinoma cells (HepG2).

KEY FINDINGS

Acyclovir, an antiviral nucleotide analog, alleviates insulin resistance by reducing blood lipids as well as oxidative stress and elevating insulin sensitivity on diabetic mice, which is in accord with results in the insulin resistance model of HepG2 cells. Mechanically, acyclovir stimulates pyruvate kinase M1 (PKM1) directly to activate adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/Sirtuin1 (SIRT1) signaling pathway, thus improving insulin resistance.

SIGNIFICANCE

The present study supports that acyclovir should be translated to remedy DM, and PKM1 might be a valuable target to develop new medicines.

Advances and insights in the diagnosis of viral infections

Viral infections are the most common among diseases that globally require around 60 percent of medical care. However, in the heat of the pandemic, there was a lack of medical equipment and inpatient facilities to provide all patients with viral infections. The detection of viral infections is possible in three general ways such as (i) direct virus detection, which is performed immediately 1-3 days after the infection, (ii) determination of antibodies against some virus proteins mainly observed during/after virus incubation period, (iii) detection of virus-induced disease when specific tissue changes in the organism. This review surveys some global pandemics from 1889 to 2020, virus types, which induced these pandemics, and symptoms of some viral diseases. Non-analytical methods such as radiology and microscopy also are overviewed. This review overlooks molecular analysis methods such as nucleic acid amplification, antibody-antigen complex determination, CRISPR-Cas system-based viral genome determination methods. Methods widely used in the certificated diagnostic laboratory for SARS-CoV-2, Influenza A, B, C, HIV, and other viruses during a viral pandemic are outlined. A comprehensive overview of molecular analytical methods has shown that the assay's sensitivity, accuracy, and suitability for virus detection depends on the choice of the number of regions in the viral open reading frame (ORF) genome sequence and the validity of the selected analytical method.

Live virus vaccination of pediatric solid organ transplant candidates within 1 month prior to transplantation: A multicenter experience

BACKGROUND

Solid organ transplant (SOT) recipients are at increased risk of vaccine-preventable illness due to the high degree of immunosuppression required following transplantation. The current recommendation is to vaccinate with live attenuated vaccines, including Measles, Mumps, and Rubella (MMR) and Varicella (VAR) vaccines, at least 4 weeks prior to transplant. However, data to support the time interval between vaccine and transplant are limited.

METHODS

We conduct a literature review of the natural history of the viruses and length of viremia following live-attenuated viral vaccines, and we describe a series of 5 cases from 2 pediatric transplant centers in which live attenuated viral vaccines were administered within 21 days prior to SOT.

RESULTS

None of the 5 children who received MMR or VAR 8-21 days prior to liver (2) and heart (3) transplant suffered from vaccine-related viral illness after transplant, even in the presence of significant immunosuppression with T-cell-depleting agents.

CONCLUSION

These cases support that shorter intervals of live vaccine administration prior to transplant may be safe, allowing the vaccination of a larger cohort of SOT candidates. Increasing pretransplant vaccinations is crucial since, in most cases, live viral vaccines are contraindicated posttransplantation, and the most effective vaccine approaches utilize prime-boost strategies, priming before and boosting after transplant.

Systematic analysis of infectious disease outcomes by age shows lowest severity in school-age children

The COVID-19 pandemic has ignited interest in age-specific manifestations of infection but surprisingly little is known about relative severity of infectious disease between the extremes of age. In a systematic analysis we identified 142 datasets with information on severity of disease by age for 32 different infectious diseases, 19 viral and 13 bacterial. For almost all infections, school-age children have the least severe disease, and severity starts to rise long before old age. Indeed, for many infections even young adults have more severe disease than children, and dengue was the only infection that was most severe in school-age children. Together with data on vaccine response in children and young adults, the findings suggest peak immune function is reached around 5-14 years of age. Relative immune senescence may begin much earlier than assumed, before accelerating in older age groups. This has major implications for understanding resilience to infection, optimal vaccine scheduling, and appropriate health protection policies across the life course.

The Cost-Effectiveness of Universal Varicella Vaccination in Italy: A Model-Based Assessment of Vaccination Strategies

Background

In 2017, varicella vaccination became mandatory for all children in Italy, based on a two-dose schedule administered at 12–15 months of age and 5 to 6 years of age. Varicella vaccines are available in different formulations (as a single vaccine or as a combination vaccine together with measles, mumps, and rubella) and are made by multiple manufacturers with different effectiveness profiles. This study calculates the cost-effectiveness of a range of varicella vaccination strategies to identify the optimal strategy for Italy.

Methods

A dynamic transmission cost-effectiveness model was applied in Italy to simulate the long-term (50 years) costs and outcomes associated with different varicella vaccination strategies. Five vaccination strategies were evaluated using the model: two doses of two different combination Measles-Mumps-Rubella-Varicella vaccines (either Vaccine A (MSD) [denoted QQVa] or Vaccine B (GSK) [denoted QQVb]); a first dose of a single Varicella vaccine followed by a second dose of a combination vaccine (either Vaccine C (MSD) followed by Vaccine A [denoted MQVa] or Vaccine D (GSK) followed by Vaccine B [denoted MQVb]); or no vaccine at all (NV). The model was adapted for Italy using publicly available Italian data and expert opinion.

Results

Over the 50-year time-horizon, in the absence of universal varicella vaccination, there would be 34.8 million varicella cases, 142 varicella-infection-related deaths, and €23 billion in societal costs. The cost per capita from a societal perspective ranged from €164.55 to €392.18 with NV being the most expensive and QQVa the least expensive. The most effective strategy was QQVa, which resulted in a 66% decrease in varicella cases and 30% reduction in varicella-related deaths compared to NV strategy. QQVa led to a net saving in societal cost around €13 billion compared to NV as the cost of vaccination was more than offset by the savings that resulted from the reduced burden of illness.

Conclusion

Varicella vaccination has a major impact on reducing varicella incidence, prevalence, and societal costs. This analysis supports the policy for universal varicella vaccination in Italy as the NV strategy was the most expensive and resulted in the poorest outcomes. QQVa offers the greatest benefits at the lowest cost and should be considered as a potential priority strategy for Italian population.

Pediatric Pyomyositis: A Rare but Important Complication of Varicella

Varicella is a common viral infection in children and most of them recover without sequelae, but serious complications can follow this infection and 6% have been reported to be musculoskeletal. A previously healthy 3-year-old Caucasian male presented with odynophagia, anorexy, fever, refusal to bear weight, and vesicular exanthema. Varicella was diagnosed, but he sustained fever around 39°C and local tenderness on the proximal lateral portion of the right leg maintaining an antalgic position. Ultrasonography and plain radiography were performed, but the magnetic resonance imaging (MRI) was performed due to the clinically worsening diagnosed pyomyositis. He was subjected to surgical debridement, and we started intravenous antibiotherapy. Streptococcus pyogenes grew in the microbiologic culture. At a 6-month follow-up, the boy did not suffer from any sequelae. The regular course of varicella is benign; however, it can occasionally develop into a more serious illness. The initial presentation of pyomyositis is often subacute, and the first symptoms may be vague. The awareness of musculoskeletal complications is imperative, and the combination of varicella's exanthema and fever followed by some limb complaint should lead to an alert attitude.

Report of Resistant Varicella Zoster Infection Treated With Donor Lymphocyte Infusion in a Pediatric Oncology Patient

We report an 8-year-old boy with disseminated, life-threatening, drug treatment-resistant varicella zoster infection occurring during standard treatment for neuroblastoma in whom viral clearance and cure was effected by donor Lymphocyte infusion from his HLA (Human leukocyte antigen)-identical twin sibling.

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.

Varicella zoster presenting as cranial polyneuropathy

Cranial polyneuropathy is commonly caused by Lyme disease. We discuss the case of a man who presented with cranial nerve deficits causing dysphagia, dysphonia and facial weakness. This diagnostic dilemma stemmed from a workup that ruled out Lyme and vascular causes leading to an expanded search for infectious explanations, which revealed varicella zoster in the cerebrospinal fluid. On review, this phenomenon is rarely reported, but has been observed with a number of herpes family viruses. In emergency department settings, clinical suspicion should be raised for VZV infection even in the absence of rash in patients that present with multiple cranial nerve palsies.

Antiviral Drugs in Newborn and Children

This article focuses on the clinically relevant approved antiviral medications available for the treatment of infants and children. A brief overview of drug categories, mechanism of action, resistance, pharmacokinetics, and side effects is provided for the more commonly prescribed antivirals. The patient categories addressed are treatment and prophylaxis of influenza, neonatal herpes simplex virus and congenital cytomegalovirus, treatment and prophylaxis of viral disease in the immunocompromised host, and a brief introduction to the antivirals available to treat hepatitis B and hepatitis C in children.

Varicella and herpes zoster vaccine development: lessons learned

INTRODUCTION

Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing latency in sensory ganglia, where its reactivation is controlled by VZV-specific T-cell immunity. Lifetime risk of VZV reactivation (zoster) is around 30%. Vaccine development was galvanised by the economic and societal burden of VZV, including debilitating zoster complications that largely affect older individuals. Areas covered: We describe the story of development, licensing and implementation of live attenuated vaccines against varicella and zoster. We consider the complex backdrop of VZV virology, pathogenesis and immune responses in the absence of suitable animal models and examine the changing epidemiology of VZV disease. We review the vaccines' efficacy, safety, effectiveness and coverage using evidence from trials, observational studies from large routine health datasets and clinical post-marketing surveillance studies and outline newer developments in subunit and inactivated vaccines. Expert commentary: Safe and effective, varicella and zoster vaccines have already made major inroads into reducing the burden of VZV disease globally. As these live vaccines have the potential to reactivate and cause clinical disease, developing alternatives that do not establish latency is an attractive prospect but will require better understanding of latency mechanisms.

Varicella associated pneumoniae in a pediatric population

BACKGROUND

Varicella pneumonia has been studied extensively in adults; it may also affect children and may require hospitalization.

METHODS

We examined pneumonia complications in children hospitalized for varicella, over a 13 year period.

RESULTS

Pneumonia occurred in 8.2% of children hospitalized for varicella. The median length of hospitalization was 6 days. No statistically significant difference in length of stay was detected between immunodepressed children and previously healthy children. The hospitalization was on average shorter in patients who started antiviral therapy within 24 h of varicella onset. None of the included patients had been previously immunized for varicella.

CONCLUSIONS

Our results support the need for increased awareness of current varicella prevention recommendations among both immunocompetent and immunodepressed individuals. In children affected by varicella, prompt antiviral therapy may be indicated to reduce the number of days of hospitalization.

Progress in the Clinical Management of Herpesvirus Infections

Antiviral drug discovery has produced a series of drugs active against herpesviruses in vitro. Several of these are now licensed and/or have been used in clinical practice. This article reviews the mechanisms of action of acyclovir, ganciclovir, penciclovir, sorivudine and foscarnet, the development of resistance to these drugs and their pharmacokinetic and cellular toxicities. Based upon the natural histories of HSV, VZV and CMV, treatment objectives for each virus are discussed and the performance of each drug matched against these objectives. Overall, it is concluded that the perfect drug for treating herpesviruses does not exist, but that significant progress has been made towards controlling several herpesvirus diseases. It is suggested that further progress will require not just improved drug discovery programmes, but also an understanding of different pathogeneses and an appreciation by practising physicians that antiviral drugs must be given early in the infectious process to achieve the best results.

Impact of Subsidies and Socioeconomic Status on Varicella Vaccination in Greater Tokyo, Japan

BACKGROUND

Although the control of varicella outbreaks is an important health issue, cost could present a major barrier for vaccination. The aim of this study is to investigate the association of vaccine subsidies and caregivers' socioeconomic status with varicella vaccine coverage of their children in Greater Tokyo, Japan, before the period that varicella vaccination was included in routine immunization program.

METHODS

Participants were recruited from two different cities. In Chiba city, parents of 18-month-old infants (N = 378) undergoing a medical examination in July 2013 were recruited at a clinic where no subsidy for varicella immunization was provided. In Nishitokyo city, parents of 24- to 30-month-old children (N = 315) undergoing a health checkup in July and August 2013 were recruited at a clinic where a partial subsidy was provided. The association between household income and varicella immunization was investigated by multivariate logistic regression stratified by city.

RESULTS

Vaccine coverage was 61.0% in Chiba city and 73.3% in Nishitokyo city. In Chiba city, odds ratios of middle and high household income for varicella immunization were 4.22 [95% confidence interval (CI): 1.65-10.7] and 5.94 (95% CI: 1.89-18.6), respectively, compared to low household income. However, household income was not associated with varicella vaccination in Nishitokyo city. Neither working status nor education was associated with vaccination in both cities.

CONCLUSION

While household income was associated with high vaccine coverage in the city with no vaccine subsidy, this association was not observed in the city where the subsidy was given, which suggests that cost is a barrier for varicella immunization. Thus, in countries where varicella vaccination is not included in routine immunization programs, introducing subsidies nationwide or routine immunization programs for varicella vaccination would be an important approach to eliminate inequality in vaccine coverage.

Polish consensus guidelines on the use of acyclovir in the treatment and prevention of VZV and HSV infections

A physician has to perform a benefit-risk assessment each time acyclovir is prescribed "off label" for children. A group of Polish infectious disease experts was created to develop evidence-based guidelines on the use of acyclovir in the treatment and prevention of varicella zoster and herpes simplex infections. In primary varicella zoster virus infections, oral acyclovir treatment is recommended in children over 12 years of age and should be considered in younger children who fall into one of the groups at risk of severe varicella. Intravenous acyclovir therapy in varicella is recommended in patients with immune deficiencies, newborns and in complicated cases. When there is a justified need for prevention of varicella, oral acyclovir prophylaxis may be considered if immunoglobulin cannot be administered, and if it is too late for vaccination. Oral acyclovir treatment of herpes zoster may be beneficial to otherwise healthy patients with a rash in places other than the trunk and in patients over 50 years of age. In immunocompetent patients with herpes simplex infections, indications for treatment with oral acyclovir include primary (genital herpes, skin herpes in children with atopic dermatitis, ocular herpes simplex, severe gingivostomatitis, paronychia and pharyngitis) and recurrent infections. Intravenous acyclovir should be administered for herpes infections in neonates, immunocompromised patients and patients who develop complications including neurological.

Use of immunization as strategy for outbreak control of varicella zoster in an institutional setting

BACKGROUND

Outbreaks of varicella gets reported often in India. However, outbreak in health care providers living in closed institutional setting and role of vaccination as post exposure prophylaxis for control of outbreak has not been studied extensively. This paper presents epidemiological investigation and control strategy undertaken in such scenario.

METHODS

This is an epidemiological investigation of chickenpox in nursing students which highlights role of early identification and appropriate control strategy to prevent explosive outbreak in high risk vulnerable population. Vaccination of all susceptible in addition to isolation of cases, quarantine of suspects and proper screening for new cases was the major control strategy adopted.

RESULTS

The index case was imported and all eight cases occurred within the incubation period of the case. Two cases occurred in students previously vaccinated for chickenpox. No second or third wave of infection occurred showing vaccination as effective tool in outbreak control strategy.

CONCLUSION

Early identification of cases and vaccination of all susceptible contributed to effective control of the outbreak.

Management of herpesvirus infections

Management of human herpesviruses remains a considerable clinical challenge, in part due to their ability to cause both lytic and latent disease. Infection with the Herpesviridae results in lifelong infection, which can reactivate at any time. Control of herpesviruses is by the innate and adaptive immune systems. Herpesviruses must evade the host innate immune system to establish infection. Once infected, the adaptive immune response, primarily CD8(+) T-cells, is crucial in establishing and maintaining latency. Latent herpesviruses are characterised by the presence of viral DNA in infected cells and limited or no viral replication. These characteristics provide a challenge to clinicians and those developing antiviral agents. The scope of this review is two-fold. First, to provide an overview of all antivirals used against herpesviruses, including their mechanism of action, pharmacokinetics, side effects, resistance and clinical uses. And second, to address the management of each of the eight herpesviruses both in the immunocompetent and immunocompromised host, providing evidence for clinical management and therapeutic options, which is important to the clinician engaged in the management of these infections.

Herpes zoster ophthalmicus in an otherwise healthy 2-year-old child

The following report describes a previously healthy 2-year-old girl with herpes zoster ophthalmicus (HZO). The child presented with a painless vesicular skin eruption covering the left forehead. There was only a history of household exposure to varicella zoster virus (VZV) and the child had not been vaccinated against VZV. PCR assays on vesicular fluid identified VZV DNA. Treatment with acyclovir was started early in the clinical course. In addition, the girl was treated with locally administered ophthalmological acyclovir ointment. Besides some dermal excoriations, a complete resolution of the HZO was achieved without sequelae.

A case of internal ophthalmoplegia associated with varicella zoster

The authors report a case of internal ophthalmoplegia in a 5-year-old boy presenting after primary varicella infection. This is an uncommon and mostly irreversible ocular manifestation after chickenpox. The internal ophthalmoplegia showed a potential mild improvement with oral acyclovir. Consideration should be given to starting treatment on presentation in such cases.

Management of chickenpox with frozen mother's milk

OBJECTIVES

If a mother has contracted chickenpox, the antibodies in her milk confer immunity against chickenpox to her breastfed babies. This passive immunization may avoid or spare the breastfed babies' symptoms of chickenpox. It is hypothesized that frozen breast milk may shorten chickenpox duration because specific antibodies against varicella zoster have been detected in human milk and they are resistant to digestion and are stable in frozen milk.

DESIGN

The clinical outcomes of chickenpox in a 9-year-old boy and his father on frozen breast milk are reported.

SETTINGS

The study comprised a varicella-vaccine-refusing family attending a private office of pediatrics.

INTERVENTIONS AND RESULTS

The boy presented with a crusted varicella rash. The medical history revealed premature cessation of the typical varicella rash on day 3. It was coincidental with a supply of frozen human milk by his mother. Next, the father (41 years old) of this patient contracted chickenpox: he was on frozen breast milk from day 2, and no new pox emerged thereafter.

CONCLUSIONS

The rash spread and numbered 50 to 150 lesions on day 2. Instead, the typical rash was expected to appear in three successive crops of lesions throughout the first week. The disease usually numbers approximately 250-500 lesions in unvaccinated healthy persons. Frozen breast milk may shorten chickenpox duration.

Towards universal childhood immunization against chickenpox?

Live attenuated varicella vaccine is available in Canada. The National Advisory Committee on Immunization recommended immunization of healthy susceptible individuals after one year of age. This was endorsed by a National Varicella Consensus Conference, provided that 90% coverage could be ensured. So far only Prince Edward Island has begun universal childhood immunization. Barriers to achieving high childhood vaccine coverage include: the perception that chickenpox is mild in children but severe in both adults and immunocompromised; concern that vaccine field effectiveness will be much lower than observed in pre-licensure efficacy trials; fear that waning immunity may increase adult cases and the associated disease burden; and uncertainty regarding long term morbidity due to vaccine strain reactivation. In fact, chickenpox is usually an uncomplicated illness in otherwise healthy individuals of all ages. Further, with varicella zoster immunoglobulin (VZIG) prophylaxis and acyclovir treatment soon after rash onset, the course in immunocompromised individuals is also usually benign. However, on a population basis, otherwise healthy children with no identifiable risk factors account for 80% to 90% of all chickenpox-associated hospital admissions and 40% to 60% of case fatalities. A more accurate assessment of the relative merits of varicella immunization should contrast the current natural history of disease (90% to 95% infected symptomatically by age 15 years, 15% lifetime risk of a moderate to severe reactivation episode) with the demonstrated vaccine effectiveness of 70% to 86% against any chickenpox, 95% to 100% against moderate to severe illness and significant reduction of frequency and severity of reactivation illness.

Varicella-related musculoskeletal complications in children

Eight children with post-varicella musculoskeletal complications were treated between 2001 and 2009. The complications that were observed were cellulitis (three children), pyomyositis (three children), osteomyelitis (two children) and gangrene (one child). On average, 8.8 days elapsed between primary varicella infection and complication. The most common presentation was pain. Before we started treating them, all children received antibiotics during interhospital transfers (average: 2.4). Interventions included drainage (eight), fasciatomy (one), arthrotomy (one), bone drilling (one), and amputation (one). Blood cultures were negative in all children. Two children had positive pus cultures for Staphylococcus aureus, one of them had a methicillin-resistant S. aureus infection. One of the four children who developed coagulopathy ended with significant morbidity. Varicella-related methicillin-resistant S. aureus osteomyelitis suggests a widening spectrum of these infections.

Aciclovir and varicella-zoster-immunoglobulin in solid-organ transplant recipients

Clear recommendations for the management of acute varicella-zoster virus (VZV) infections for cases of significant exposure and the use of prophylactic drugs after solid-organ transplantation are missing due to the lack of evidence by prospective studies. Heterogeneity in patient groups, patient numbers, age groups, immunosuppressive regimens, timing, and dosage of aciclovir and/or varicella-zoster immunoglobulin (VZIG), pre-transplant vaccination or VZV wild-type infection and inconsistency of data make comparability of different studies impossible. Although the benefit of aciclovir and/or VZIG is uncertain in immunosuppressed children, prospective controlled double-blind studies are not feasible for ethical considerations as fatal cases with disseminating varicella disease are well known in these patient groups despite the use of aciclovir and/or VZIG, whereas severe side-effects of these drugs are rare. However, a reporting bias is likely as mainly severe or fatal cases might have been predominantly published or cases of successfully used aciclovir and/or VZIG in mild cases or in cases of breakthrough infections after vaccination. As neither VZIG prophylaxis nor treatment with intravenous aciclovir offers complete protection against severe VZV infection to immunosuppressed pediatric solid-organ transplant recipients, high priority should be given to vaccination against VZV prior to transplantation, and, most importantly, in their close contact persons. Clinical observations suggest that only assessment of humoral immunity together with cellular immunity may allow predication about protection in exposed patients.

Varicella zoster virus infection: clinical features, molecular pathogenesis of disease, and latency

Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which virus becomes latent in cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia along the entire neuraxis. Years later, in association with a decline in cell-mediated immunity in elderly and immunocompromised individuals, VZV reactivates and causes a wide range of neurologic disease. This article discusses the clinical manifestations, treatment, and prevention of VZV infection and reactivation; pathogenesis of VZV infection; and current research focusing on VZV latency, reactivation, and animal models.

Varicella

Varicella-zoster virus, a herpesvirus, causes varicella (chickenpox) and, after endogenous reactivation, herpes zoster (shingles). Varicella, which is recognised by a characteristic vesicular rash, arises mainly in young children, although older individuals can be affected. In immunocompetent patients, symptoms are usually mild to moderate, but an uncomplicated severe case can have more than 1000 lesions and severe constitutional symptoms. Serious complications--including central nervous system involvement, pneumonia, secondary bacterial infections, and death--are sometimes seen. Varicella can be prevented by vaccination. Vaccine is about 80-85% effective against all disease and highly (more than 95%) effective in prevention of severe disease. In the USA, a routine childhood immunisation programme has reduced disease incidence, complications, hospital admissions, and deaths in children and in the general population, indicating strong herd immunity. Similar immunisation programmes have been adopted by some other countries, including Uruguay, Germany, Taiwan, Canada, and Australia, and are expected to be implemented more widely in future.

Tolerability of treatments for postherpetic neuralgia

Herpes zoster occurs in up to 20% of people infected with varicella-zoster virus, due to reactivation of the virus from latently infected sensory ganglia. Although pain is a typical feature of acute zoster, pain persisting for more than a month after resolution of the rash is less common and is termed postherpetic neuralgia (PHN). The pain associated with PHN is neuropathic in origin and is notoriously difficult to treat. The incidence of herpes zoster and its associated complications both increase with age, so PHN should be seen more commonly in an aging population. Vaccination with live, attenuated varicella vaccine is safe and efficacious, particularly in children. It decreases the incidence of acute varicella and subsequent herpes zoster. Aciclovir is well tolerated, with renal toxicity only at high intravenous doses. Treatment of acute varicella with aciclovir attenuates acute illness but does not prevent herpes zoster. Treatment of herpes zoster with aciclovir or its derivatives minimises symptoms and may reduce the rate of PHN. Foscarnet is an alternative for an aciclovir-resistant virus but its use is limited by renal and CNS toxicity. Corticosteroids reduce acute pain in herpes zoster but do not affect the incidence of PHN. Their use in some patients may be limited by adverse effects such as gastritis and impaired glucose tolerance. Treatment of established PHN is difficult and may require a holistic approach. Tricyclic antidepressants and gabapentin are the systemic agents with the most proven benefit, although opioids such as oxycodone and NMDA receptor antagonists such as ketamine may be useful in some people. Adverse effects from tricyclic antidepressants are common but usually mild, while gabapentin is generally well tolerated. Although effective, the relatively common adverse effects of opioids and ketamine limit their usefulness in treating PHN. Topical treatment with 5% lidocaine patch or capsaicin is of benefit in some patients and is generally well tolerated. Intrathecal methyl prednisolone may be considered for intractable pain but efficacy and safety have not been confirmed.

[Fatal outcome of varicella zoster sepsis in a 22-year old patient]

Infection with Varicella zoster virus (VZV) usually occurs in children up to 15 years with mild symptoms. We present a case of a 22-year old man with a fatal varicella zoster infection. He developed fulminant hepatitis with acute liver failure and an acute respiratory distress syndrom (ARDS). In this article the general aspects of VZV infection are discussed. Treatment options and previous publications are reviewed.

Acyclovir for treating varicella in otherwise healthy children and adolescents

BACKGROUND

Acyclovir has the potential to shorten the course of illness which may result in reduced costs and morbidity associated with chickenpox.

OBJECTIVES

1) To examine the evidence evaluating the efficacy of acyclovir in alleviating symptoms of chickenpox and shortening the duration of illness. 2) To examine complications of chickenpox and adverse effects associated with acyclovir as reported in the relevant trials.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2005), MEDLINE (January 1966 to June 2005), and EMBASE (1988 to June 2005). The reference lists of all relevant articles were reviewed. The primary author of relevant studies and the pharmaceutical company that manufactures acyclovir were contacted.

SELECTION CRITERIA

Randomized controlled trials that evaluated otherwise healthy children zero to 18 years of age, with chickenpox.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the studies for eligibility. Two authors independently assessed methodological quality of the relevant studies using the Jadad scale and allocation concealment. Differences were resolved by consensus. Data were extracted by one author using a structured form and checked by a second. Continuous data were converted to the weighted mean difference (WMD). Weighted mean differences were combined into an overall estimate using random effects. There were too few studies to consider exploring statistical heterogeneity between studies (i.e., differences in reported effects), formally, or to assess for publication bias.

MAIN RESULTS

Three studies were included. Study quality was three (n = 2) and four (n = 1) on the Jadad scale. Acyclovir was associated with a reduction in the number of days with fever (-1.1 days, 95% CI -1.3 to -0.9) and in reducing the maximum number of lesions (-76 lesions, -145 to -8). Results were less supportive with respect to the number of days to no new lesions and the number of days to the relief of itching. There were no clinically important differences between acyclovir and placebo with respect to complications associated with chickenpox or adverse effects associated with the treatment.

AUTHORS' CONCLUSIONS

Acyclovir appears to be effective in reducing the number of days with fever and the maximum number of lesions among otherwise healthy children with chickenpox. The results were less convincing with respect to the number of days to no new lesions and relief of itchiness. The clinical importance of acyclovir treatment in otherwise healthy children remains uncertain.

Antiviral therapies in children: has their time arrived?

The increase in the number and classes of antiviral agents that has occurred since the 1980s is remarkable. The rapid expansion in therapeutic options for previously untreatable illnesses challenges clinicians to gain familiarity and experience with these new drugs, especially with regard to their use in children. This article describes the clinical utilities, pharmacokinetics, and adverse effects of these new drugs to empower practitioners to use them appropriately.

Detection of antibodies to varicella-zoster virus using a latex agglutination assay

BACKGROUND

There is a clinical need to have a rapid and sensitive means to identify persons with immunity to varicella-zoster virus (VZV).

OBJECTIVES

We evaluated a simple-to-perform assay for detecting antibodies to VZV using a commercial latex agglutination (LA) test, in which dilutions of test sera were added to latex particles that had been coated with VZV glycoprotein antigens.

STUDY DESIGN

Sera obtained from patients, including recipients of varicella vaccine, whose clinical immune status to VZV was known, were tested by LA and the results compared to those obtained by a standard indirect immunofluorescence assay (FAMA). Using the LA test, long-term persistence of antibodies in leukemic and adult recipients of varicella vaccine were determined.

RESULTS

The LA test compared favorably with FAMA in varicella susceptibles and immunes. 741 acute sera were negative and 741 convalescent varicella sera were positive by LA. Antibodies to VZV were found to persist for as long as 11 years in most recipients of varicella vaccine (n = 145). Geometric mean titers were higher by LA than FAMA. Prozone phenomena were noted in about 5% of antibody-positive sera. Results from this test are available in less than an hour, and no special equipment is required.

CONCLUSIONS

This assay is rapid, simple to perform, and inexpensive. It is particularly useful for identifying individuals who are immune to varicella, including those who have been immunized in the distant past. The main problem associated with the test is that prozone phenomena can occur; these may be avoided by testing sera at various dilutions.

Herpes zoster in otherwise healthy children

In normal infants and children, zoster can occur at any time after varicella or varicella vaccination. It is usually diagnosed clinically: a unilateral vesicular eruption following a dermatome or dermatomes. The incidence of zoster increases with age, although children who have had varicella during the first year of life (or in utero) are at increased risk of developing zoster. The incidence of zoster is less after varicella vaccination than after natural infection. Zoster in children is frequently mild, postzoster neuralgia rarely if ever occurs, and antiviral therapy is usually not needed. In a previously normal child with zoster, if the history and physical examination are normal, a laboratory search for occult immunodeficiency or malignancy is not needed. We present five cases of zoster in healthy children and review zoster in the pediatric age group.