Controlled trial of acyclovir for chickenpox evaluating time of initiation and duration of therapy and viral resistance

Identification of novel potential inhibitors of varicella-zoster virus thymidine kinase from ethnopharmacologic relevant plants through an in-silico approach

Although Varicella or chickenpox infection which is caused by the varicella-zoster virus (VZV) has significantly been managed through vaccination, it remains an infection that poses threats to the nearest future due to therapeutic drawbacks. The focus of this research was geared towards in silico screening for the identification of novel compounds in plants of ethnopharmacological relevance in the treatment of chicken pox in West Africa. The work evaluated 65 compounds reported to be present in Achillea millefolium, Psidium guajava and Vitex doniana sweet to identify potential inhibitors of thymidine kinase, the primary drug target of varicella zoster virus. Out of the 65 compounds docked, 42 of these compounds were observed to possess binding energies lower than -7.0 kcal/mol, however only 20 were observed to form hydrogen bond interactions with the protein. These interactions were elucidated using LigPlot⁺ and MM-PBSA analysis with residue Ala134 predicted as critical for binding. Pharmacological profiling predicted three potential lead compounds comprising myricetin, apigenin- 4' -glucoside and Abyssinone V to possess good pharmacodynamics properties and negligibly toxic. The molecules were predicted as antivirals including anti-herpes and involved in mechanisms comprising inhibition of polymerase, ATPase and membrane integrity, which were corroborated previously in other viruses. These drug-like compounds are plausible biotherapeutic moieties for further biochemical and cell-based assaying to discover their potential for use against chickenpox. Communicated by Ramaswamy H. Sarma.

Acute cerebellitis in children: an eleven year retrospective multicentric study in Italy

Background

Acute cerebellitis (AC) and acute cerebellar ataxia (ACA) are the principal causes of acute cerebellar dysfunction in childhood. Nevertheless. there is no accepted consensus regarding the best management of children with AC/ACA: the aim of the study is both to assess clinical, neuroimaging and electrophysiologic features of children with AC/ACA and to evaluate the correlation between clinical parameters, therapy and outcome.

Methods

A multicentric retrospective study was conducted on children ≤ 18 years old admitted to 12 Italian paediatric hospitals for AC/ACA from 01/01/2003 to 31/12/2013. A score based on both cerebellar and extracerebellar signs/symptoms was computed for each patient. One point was given for each sign/symptom reported. Severity was divided in three classes: low, moderate, severe.

Results

A total of 124 children were included in the study. Of these, 118 children received a final diagnosis of ACA and 6 of AC. The most characteristic finding of AC/ACA was a broad-based gait disturbance. Other common symptoms included balance disturbances, slurred speech, vomiting, headache and fever. Neurological sequelae were reported in 6 cases (5%) There was no correlation among symptoms, cerebrospinal fluid findings, clinical outcome. There was no correlation between clinical manifestations and clinical score on admission and length of hospital stay, sex, age and EEG findings with sequelae (P > 0.05).

Children with pathological magnetic resonance imaging (MRI) or computed tomography (CT) had a higher probability of having clinical sequelae.

Treatment was decided independently case by case. Patients with a higher clinical score on admission had a higher probability of receiving intravenous steroids.

Conclusions

We confirmed the literature data about the benign course of AC/ACA in most cases but we also highlighted a considerable rate of patients with neurological sequelae (5%). Pathological MRI or CT findings at admission correlate to neurological sequelae. These findings suggest the indication to perform an instrumental evaluation in all patients with AC/ACA at admission to identify those at higher risk of neurological outcome. These patients may benefit from a more aggressive therapeutic strategy and should have a closer follow-up. Randomized controlled trials are needed to confirm these observations. The ultimate goal of these studies could be to develop a standardized protocol on AC/ACA. The MRI/CT data, associated with the clinical manifestations, may allow us to define the class risk of patients for a neurological outcome.

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.

Varicella zoster virus infection

Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1.

Acute cerebellitis in varicella: a ten year case series and systematic review of the literature

Background

Acute cerebellitis (AC) is the most common neurological complication of varicella. Nevertheless, it has been scarcely studied. The objective of this study were to asses the occurrence of AC among children hospitalized for varicella and to analyze its specific clinical picture and outcome.

Methods

We retrospectively reviewed the medical records of children admitted to the hospital for varicella between 1^st October 2003 and 1^st June 2013 and we compared our results with literature. Children were all unvaccinated for varicella.

Results

In our case series, AC was found out in 48 out of 457 patients (10.5%). The highest frequency of AC was observed in children from 1 to 5 years of age (60.9%). The most characteristic symptom of AC was a broad-based gait disturbance that progressed gradually over the course of a few days (95.8%). Other common symptoms included slurred speech (37.5%), vomiting (31.25%), headache (29.16%), dysmetry (25%) and tremor (22.91%). After a long hospitalization (median of 11 days), all but one children were dismissed without invalidating sequelae.

Conclusions

Data from this study may help to better address the problem of varicella cerebellar complications in hospitalized children and to monitor changes over time caused by an increase in vaccination coverage.

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.

Chickenpox in adults - clinical management

Acute varicella zoster virus (VZV) infection, or chickenpox, is still perceived by many as a mild infection of childhood. However, chickenpox is increasingly common in adults and adolescents who together with immunosuppressed individuals are at a higher risk of severe infection. Antiviral therapy is available which both ameliorates symptoms and decreases the severity of chickenpox if administered early in the course of the infection. Passive immunisation with varicella zoster immunoglobulin (VZIG) may prevent or attenuate infection following exposure to varicella of an immunocompromised or pregnant individual or a neonate. Active immunisation is available and is universal in many developed countries. This review reflects current best practice in management of chickenpox in adults by specialist physicians in the UK. The accompanying flowchart has been formulated to guide emergency physicians and general practitioners through the decision-making process regarding treatment and admission for specialist care.

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.

Evidenzbasierte Therapie von Herpes-Virus-Erkrankungen der Haut

Six questions regarding varicella-zoster virus-related skin diseases are addressed. The Cochran Library, MEDLINE, Clinical Evidence and several guideline providers were searched for evidence. The level of evidence in papers was appraised according to the Oxford Centre for Evidence-based Medicine Levels of Evidence. The current evidence for antiviral therapy of chickenpox in immunocompetent children, adults and pregnancy, recommendation of varicella vaccination, effect of time of initiation of antiviral therapy in acute zoster as well as route of treatment with regard to onset of post-zoster neuralgia are covered.

Évaluation du traitement ambulatoire de la varicelle de l’enfant

BACKGROUND

Varicella, an almost compulsory affection in children, is complicated in 2% of cases. Some treatments such as powders and non-steroidial anti-inflammatories (NSAIs) may favorise or worsen infectious complications.

OBJECTIVE

To assess out-patient prescriptions in children presenting with varicella.

METHODS

Three methods were used. Collection of the out-patient prescriptions in children (n=122) subsequently presenting with varicella in one of the hospitals in the North of France conducted from January to May 2003. A telephone survey was made among 50 general practitioners in the same area in March 2003. This collected not only the prescription of the last case reported, but also the intended prescriptions when confronted with a simulated case of the disease.

RESULTS

Powders were prescribed in 44 to 54% of cases, NSAIs in 14 to 16%, aspirin in 2 to 4%, and oral acyclovir in 4%. The three assessment methods did not reveal any differences in the prescription of antibiotics, more frequent in the children subsequently visiting the hospital (25 vs. 6%), and the prescriptions of paracetamol. Only 38% of the prescriptions during clinical cases corresponded to the guidelines.

CONCLUSION

It is crucial that practitioners be informed on the treatment of varicella and the risks of severe cutaneous surinfections enhanced by certain prescriptions.

Infectious disease capsules: a pox on your house

A 31-year-old, previously healthy white man presented to the emergency department with complaints of malaise, fevers, shortness of breath, a non-productive cough, and a "rash." His physical exam revealed a temperature of 100.2F, a pulse of 129 bpm, respiratory rate of 14 BPM, and blood pressure of 140/74 mm Hg. He was alert, oriented, and in no distress. His oropharynx was dry, his neck was supple, and cervical lymphadenopathy was absent. He had tachycardia, bilateral wheezes, and rhonchi with prolonged expirations. There was a diffuse vesicular eruption enveloping his entire body with involvement sparing his palms and soles (Figures 1 and 2). Laboratory values showed a hemoglobin of 16.0 g/dL and a white blood cell count of 7100 cells/pL, with 39%neutrophils, 23% bands, and 35% lymphocytes. His platelet count was mildly decreased to 86,000 x 103/pL. Chest radiograph revealed bilateral diffuse interstitial infiltrates. A diagnosis of acute varicella-zoster virus pneumonia (varicella pneumonia) was made, and the patient was started on IV acyclovir (10 mg/kg every 8 hours). Upon further questioning, the patient stated that his daughter had been diagnosed with "chickenpox" 7 days ago. The patient had numerous exposures to chickenpox in the past but had never developed clinical expressions of varicella. He was not at risk for HIV infection, not having multiple sexual partners, IV drug abuse, or blood transfusions. During the 1 day of in-hospitalization, his fever abated and the pulmonary signs diminished. Following discharge, IV acyclovir was replaced by valacyclovir to complete a 7-day course of therapy.

Outcome of enterovirus 71 infections with or without stage-based management: 1998 to 2002

BACKGROUND

Enterovirus 71 (EV71) infection may progress through four stages, one of which is cardiopulmonary failure. In Taiwan in 1998 almost all the EV71 patients with cardiopulmonary failure died. To improve clinical outcome of EV71 patients, we developed a stage-based management program in 2000.

METHODS

The medical records of 196 EV71 patients who did not have stage-based management (1998 to 1999) and of 331 EV71 patients who did (2000 to 2002) at Chang Gung Children's Hospital were reviewed for demographic characteristics, clinical syndromes, case-fatality rates and sequelae. We compared and analyzed the results for the 2 groups.

RESULTS

Of the patients who did not receive stage-based management, 83% (15 of 18) of cases with both central nervous system (CNS) involvement and cardiopulmonary failure died during the acute stage of the infection. Two patients died at convalescence, and 1 had sequelae of dysphagia and limb weakness. By contrast of the patients who received stage-based management, 33% (12 of 36) of patients with CNS and cardiopulmonary failure died during the acute stage, 8% (3 of 36) died at convalescence, 14% (5 of 36) recovered and 43% (16 of 36) had severe sequelae of central hypoventilation, dysphagia and limb weakness (P < 0.001). For cases with CNS and cardiopulmonary failure, multivariate analysis showed that age older than 2 years and cerebro-spinal fluid white blood cell count >100/microl were associated with a increase in acute mortality [95% confidence interval (CI) 1.9 to 105.3, P = 0.001; 95% CI 1.1 to 66.6, P = 0.04, respectively], but stage-based management was significantly associated with a reduction in acute mortality (95% CI 0.007 to 0.24; P = 0.0004). Stage-based management did not affect the outcome of cases with CNS involvement alone.

CONCLUSIONS

Stage-based management reduced the case fatality rate of EV71-related cardiopulmonary failure, but two-thirds of the survivors had severe sequelae.

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 1, 2003), MEDLINE (January 1966 to May 2003), and EMBASE (1988 to April 2003). 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 reviewers independently reviewed the studies for eligibility. Two reviewers 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 reviewer 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.

REVIEWERS' 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 controversial.

Acyclovir for treating varicella in otherwise healthy children and adolescents: a systematic review of randomised controlled trials

BACKGROUND

Acyclovir has the potential to shorten the course of chickenpox which may result in reduced costs and morbidity. We conducted a systematic review of randomised controlled trials that evaluated acyclovir for the treatment of chickenpox in otherwise healthy children.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched. The reference lists of relevant articles were examined and primary authors and Glaxo Wellcome were contacted to identify additional trials. Two reviewers independently screened studies for inclusion, assessed study quality using the Jadad scale and allocation concealment, and extracted data. Continuous data were converted to a weighted mean difference (WMD). Overall estimates were not calculated due to differences in the age groups studied.

RESULTS

Three studies were included. Methodological quality was 3 (n = 2) and 4 (n = 1) on the Jadad scale. Acyclovir was associated with a significant reduction in the number of days with fever, from -1.0 (95% CI -1.5,-0.5) to -1.3 (95% CI -2.0,-0.6). Results were inconsistent with respect to the number of days to no new lesions, the maximum number of lesions and relief of pruritus. There were no clinically important differences between acyclovir and placebo with respect to complications or adverse effects.

CONCLUSION

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

Antiviral treatment of varicella in pediatric practice in the Latium region of Italy: results of an observational study

BACKGROUND

The optimal management of chickenpox in children is a controversial issue, at least in Europe. This study was designed to describe chickenpox in children and its reported management by pediatricians working for the National Health Service in the Latium region of Italy.

METHODS

A questionnaire collected information on the duration, complications and treatment of the disease between September, 1998, and May, 1999, by participant pediatricians who enrolled 1094 patients in community pediatric practice.

RESULTS

Secondary and tertiary cases of the disease in the same household were more severe than the primary cases. Acyclovir was given to 50% of the children, with a tendency to treat more severely ill children. The duration of the disease was significantly less in children receiving acyclovir within the first 24 h of rash (7.6 days 9.0). No complications requiring hospitalization were reported.

CONCLUSIONS

The use of antiviral drugs is not consistent among pediatricians. Clear guidelines are needed to minimize the use of drugs and to identify children who are likely to benefit most from antiviral therapy.