Complications of varicella zoster virus reactivation

A Rare Case of Varicella-Zoster Virus Meningitis With High Intracranial Pressure in an Immunocompetent Adult

Varicella-zoster virus (VZV) is an alphaherpesvirus causing varicella (chickenpox) and herpes zoster. While varicella typically presents with a vesicular rash, latent VZV may reactivate within the sensory ganglia causing shingles, characterized by painful vesicular rash, which may lead to neurologic complications such as aseptic meningitis. This case explores an atypical presentation in an immunocompetent young man with VZV meningitis lacking the characteristic skin rash but featuring elevated intracranial pressure. A literature review revealed rare instances of VZV-related neurologic disease without typical skin manifestations, suggesting the virus's potential to affect the central nervous system directly. Treatment with intravenous acyclovir is recommended, with ganciclovir as an alternative treatment option. This case emphasizes the importance of considering VZV meningitis in the differential diagnosis of patients presenting with viral meningitis symptoms, with or without dermatomal rash or immunocompromised conditions.

Varicella Zoster vaccination in hemodialysis patients: The state of the art

Varicella Zoster Virus (VZV) infection is a common childhood exanthematous disease, which in adults and immunocompromised people may result in severe neurologic complications. Up to one-third of infected subjects may have VZV clinical reactivation particularly if immunocompromised. Patients affected by end-stage renal disease on hemodialysis present immunodepression that contributes to their higher incidence of VZV infections and reactivation. While antiviral treatment in these patients shows low efficacy, the prevention of VZV through vaccination avoids the primary infection and the risk of reactivation. Two VZV vaccines are currently available: the live attenuate Zoster Vaccine (LZV) and a Recombinant Zoster Vaccine (RZV), with the latter appearing to provide greater efficacy. Given the higher incidence of VZV infection and reactivation, the lesser response to antivirals and the lower impact of VZ vaccine in hemodialysis patients in terms of side effects, a higher diffusion of VZV vaccination should be promoted by nephrologists in these patients in particular in those with future transplant opportunities.

Vestibular Dysfunction Secondary to Reactivation of the Neurotropic Virus VZV After COVID-19: A Case Study

BACKGROUND The novel coronavirus COVID-19 infection, caused by the SARS-CoV-2 virus, was declared a global pandemic by the World Health Organization (WHO) in March 2020. As of April 14, 2021, the virus has impacted the lives of over 138 million lives globally, with hundreds of thousands more impacted each day. COVID-19 has resulted in a multitude of clinical manifestations such as respiratory pathology, cardiovascular complications, and neurological dysfunction, and recent evidence points to potential changes in vestibular function secondary to COVID-19 infection. CASE REPORT We present the case of a 67-year-old female patient presenting with vertigo, hearing loss, tinnitus, aural dullness, dizziness, and imbalance following a diagnosis of shingles after contracting COVID-19. Results of a comprehensive balance evaluation were suggestive of a right peripheral vestibulopathy, otolith dysfunction, and a right-sided sensorineural hearing loss. The patient's subjective and objective data may support the claim that COVID-19 can lead to an increase in cases of vestibular dysfunction after reactivation of neurotropic viruses. CONCLUSIONS Our study and others suggest the possibility of vestibular deficits following the reactivation of VZV following a period of immunosuppression in conjunction with the lowered cell-mediated immunity caused by COVID-19. Additionally, vestibular interventions such as advanced vestibular treatment could be used to improve vestibular function in a linear manner.

Gastrointestinal tract and viral pathogens

Viral gastroenteritis is the most common viral illness that affects the gastrointestinal (GI) tract, causing inflammation and irritation of the lining of the stomach and intestines. Common signs and symptoms associated with this condition include abdominal pain, diarrhea, and dehydration. The infections commonly involved in viral gastroenteritis are rotavirus, norovirus, and adenovirus, which spread through the fecal-oral and contact routes and cause non-bloody diarrhea. These infections can affect both immunocompetent and immunocompromised individuals. Since the pandemic in 2019, coronavirus gastroenteritis has increased in incidence and prevalence. Morbidity and mortality rates from viral gastroenteritis have declined significantly over the years due to early recognition, treatment with oral rehydration salts, and prompt vaccination. Improved sanitation measures have also played a key role in reducing the transmission of infection. In addition to viral hepatitis causing liver disease, herpes virus, and cytomegalovirus are responsible for ulcerative GI disease. They are associated with bloody diarrhea and commonly occur in im-munocompromised individuals. Hepatitis viruses, Epstein-Barr virus, herpesvirus 8, and human papillomavirus have been involved in benign and malignant diseases. This mini review aims to list different viruses affecting the GI tract. It will cover common symptoms aiding in diagnosis and various important aspects of each viral infection that can aid diagnosis and management. This will help primary care physicians and hospitalists diagnose and treat patients more easily.

Varicella Pneumonia in Otherwise Healthy 31-Year-Old Female Nonsmoker With No Prior Varicella Immunity

Varicella pneumonia is a relatively rare but severe complication of primary varicella infection. It primarily affects adults and is exacerbated by risk factors such as smoking, immunocompromised status, and male gender. Left untreated, the mortality associated with varicella pneumonia is high and ranges from 10-30 percent in the literature. This is a case of an adult female patient with no prior immunity to varicella who presented with increased oxygen requirements approximately 5 days after the onset of cutaneous symptoms. Her symptoms quickly improved after 1-day post administration of valacyclovir, and on discharge, she was prescribed a 7-day course of valacyclovir. Early treatment with acyclovir is the mainstay of treatment and is essential as it has been shown to reduce long-term complications and decrease mortality. Despite the low incidence of varicella pneumonia among patients with primary varicella infection, the index of suspicion for varicella pneumonia among patients with primary varicella infection should be high in the setting of increased oxygen requirements due to the mortality and symptomatic benefits of early treatment.

Pole-to-pole involvement of varicella zoster virus reactivation following COVID-19 vaccination

The aim of this study is to report the clinical features, imaging findings including confocal imaging, corneal nerve fiber analysis, and management outcomes in a series of three cases of varicella zoster virus (VZV) reactivation following one dose of coronavirus disease 2019 (COVID-19) vaccination. This was a retrospective and observational study. All the patients who developed uveitis post-vaccination were pooled together. Patients who had VZV reactivation were included. Two cases had polymerase chain reaction positive for VZV from aqueous humor. At the time of presentation, IgG and IgM spike protein antibodies for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were tested. Out of this pool, three patients with classical features to describe pole-to-pole manifestations were chosen. A 36-year-old lady with post-vaccination sclerokeratouveitis associated with reactivation of herpes zoster ophthalmicus, a 56-year-old lady with post-vaccination acute anterior uveitis associated with herpes zoster ophthalmicus, and a 43-year-old gentleman with post-vaccination acute retinal necrosis were included. We present a possible link between anti-SARS-CoV-2 virus vaccination and varicella zoster reactivation in these patients and also describe the clinical features, imaging findings including confocal imaging, corneal nerve fiber analysis, and management with detailed discussion.

Exploring the causal role of the immune response to varicella-zoster virus on multiple traits: a phenome-wide Mendelian randomization study

BACKGROUND

The immune response to infections could be largely driven by the individual's genes, especially in the major histocompatibility complex (MHC) region. Varicella-zoster virus (VZV) is a highly communicable pathogen. In addition to infection, the reactivations of VZV can be a potential causal factor for multiple traits. Identification of VZV immune response-related health conditions can therefore help elucidate the aetiology of certain diseases.

METHODS

A phenome-wide Mendelian randomization (MR) study of anti-VZV immunoglobulin G (IgG) levels with 1370 traits was conducted to explore the potential causal role of VZV-specific immune response on multiple traits using the UK Biobank cohort. For the robustness of the results, we performed MR analyses using five different methods. To investigate the impact of the MHC region on MR results, the analyses were conducted using instrumental variables (IVs) inside (IV_mhc) and outside (IV_no.mhc) the MHC region or all together (IV_full).

RESULTS

Forty-nine single nucleotide polymorphisms (IV_full) were associated with anti-VZV IgG levels, of which five (IV_mhc) were located in the MHC region and 44 (IV_no.mhc) were not. Statistical evidence (false discovery rate < 0.05 in at least three of the five MR methods) for a causal effect of anti-VZV IgG levels was found on 22 traits using IV_mhc, while no evidence was found when using IV_no.mhc or IV_full. The reactivations of VZV increased the risk of Dupuytren disease, mononeuropathies of the upper limb, sarcoidosis, coeliac disease, teeth problems and earlier onset of allergic rhinitis, which evidence was concordant with the literature. Suggestive causal evidence (P < 0.05 in at least three of five MR methods) using IV_full, IV_mhc and IV_no.mhc was detected in 92, 194 and 56 traits, respectively. MR results from IV_full correlated with those from IV_mhc or IV_no.mhc. However, the results between IV_mhc and IV_no.mhc were noticeably different, as evidenced by causal associations in opposite directions between anti-VZV IgG and ten traits.

CONCLUSIONS

In this exploratory study, anti-VZV IgG was causally associated with multiple traits. IVs in the MHC region might have a substantial impact on MR, and therefore, could be potentially considered in future MR studies.

Abdominal paresis and pseudo-hernia secondary to herpes zoster infection: A case report and systematic analysis

Background

Abdominal pseudo-hernia secondary to herpes zoster infection is rare and the clinical features and factors affecting recovery remain poorly understood.

Aim

We aimed to describe the clinical features of patients with abdominal pseudo-hernia secondary to herpes zoster infection and attempt to identify factors associated with poor recovery.

Design

Literature review and retrospective Analysis.

Methods

We report a case and performed a retrospective, systematic review of the demographic background, clinical characteristics and outcomes of patients with abdominal pseudo-hernia secondary to herpes zoster infection in the literature over 20 years (2001-2021).

Results

We analyzed a total of 34 cases. The median age of the patients was 71.5 years. Most of the patients were male (n = 27, 79.4%). The most frequently affected dermatome was T-11 (n = 20, 66.7%). In four (12.5%) patients, abdominal pseudo-hernia started before the onset of rash. In all patients (n = 12, 100%) who underwent nerve conduction study and electromyography, there was electrophysiological evidence of acute denervation. Seven patients (20.6%) had imaging features suggestive of abdominal wall atrophy and denervation. The majority of patients had good recovery. The median follow-up time was 3 (15 days-12 months) months. Patients with pre-existing medical conditions (p = 0.03) were more likely to have a worse recovery.

Conclusion

Abdominal pseudo-hernia is a rare complication of herpes zoster infection with a good prognosis for recovery, although patients with pre-existing disease appear to recover worse. In rare cases, it may occur before the onset of typical zoster rashes and should be suspected, especially in older, male patients with involvement of the lower thoracic dermatomes.

Evaluation of Cellular miR-122 Expression in Association with the Presence of Varicella-Zoster Virus among Central Nervous System Tumors

Background: Brain tumors are all primary central nervous system (CNS) tumors with unclear etiologies and viral infections, especially human herpesviruses, which have emerged as a hot topic for comprehensive research. Objectives: The present study aimed at assessing the molecular epidemiology of varicella-zoster virus (VZV) and its association with microRNA 122 (miR-122) expression in CNS tumor samples. Methods: Fresh frozen tissue samples were collected from 60 CNS tumor patients and 45 healthy controls. A nested PCR assay was performed to detect the VZV-DNA. Subsequently, the expression level of miR-122 was evaluated in the CNS tumor tissue samples of patients and the brain tissue samples were obtained from healthy controls, using a real-time PCR assay. Results: Of 60 patients with CNS tumors, 29 were men and 31 were women. VZV-DNA was detected in 13.3% of the CNS tumor tissue specimens. There was no statistically significant association between the presence of VZV-DNA and different types of CNS tumors (P > 0.05). Furthermore, the expression level of miR-122 was significantly downregulated in the CNS tumor tissue samples obtained from the patients compared with those of the healthy controls (P < 0.05). Additionally, the expression level of miR-122 was significantly lower in the VZV-positive tumor samples as compared with those of the VZV-negative tumor samples and the healthy controls. Conclusions: Although VZV plays no direct role in the development of CNS tumors, the virus may affect the biology of CNS tumors by decreasing the expression levels of miR-122, which consequently leads to an increased risk of malignancy. However, the experimental data are not conclusive enough; so, further investigations are needed.

Activation of Interferon-Stimulated Genes following Varicella-Zoster Virus Infection in a Human iPSC-Derived Neuronal In Vitro Model Depends on Exogenous Interferon-α

Varicella-zoster virus (VZV) infection of neuronal cells and the activation of cell-intrinsic antiviral responses upon infection are still poorly understood mainly due to the scarcity of suitable human in vitro models that are available to study VZV. We developed a compartmentalized human-induced pluripotent stem cell (hiPSC)-derived neuronal culture model that allows axonal VZV infection of the neurons, thereby mimicking the natural route of infection. Using this model, we showed that hiPSC-neurons do not mount an effective interferon-mediated antiviral response following VZV infection. Indeed, in contrast to infection with Sendai virus, VZV infection of the hiPSC-neurons does not result in the upregulation of interferon-stimulated genes (ISGs) that have direct antiviral functions. Furthermore, the hiPSC-neurons do not produce interferon-α (IFNα), a major cytokine that is involved in the innate antiviral response, even upon its stimulation with strong synthetic inducers. In contrast, we showed that exogenous IFNα effectively limits VZV spread in the neuronal cell body compartment and demonstrated that ISGs are efficiently upregulated in these VZV-infected neuronal cultures that are treated with IFNα. Thus, whereas the cultured hiPSC neurons seem to be poor IFNα producers, they are good IFNα responders. This could suggest an important role for other cells such as satellite glial cells or macrophages to produce IFNα for VZV infection control.

Viral Infection and Antiviral Treatments in Ocular Pathologies

Ocular viral infections are common and widespread globally. These infectious diseases are a major cause of acute red eyes and vision loss. The eye and its nearby tissues can be infected by several viral agents, causing infections with a short course and limited ocular implications or a long clinical progression and serious consequences for the function and structure of the ocular region. Several surveillance studies underline the increased emergence of drug resistance among pathogenic viral strains, limiting treatment options for these infections. Currently, in the event of resistant infections, topical or systemic corticosteroids are useful in the management of associated immune reactions in the eye, which contribute to ocular dysfunction. Many cases of viral eye infections are misdiagnosed as being of bacterial origin. In these cases, therapy begins late and is not targeted at the actual cause of the infection, often leading to severe ocular compromises, such as corneal infiltrates, conjunctival scarring, and reduced visual acuity. The present study aims at a better understanding of the viral pathogens that cause eye infections, along with the treatment options available.

Recognition & management of varicella infections and accuracy of antimicrobial recommendations: Case vignettes study in the US

Background

In 1995, the CDC recommended one-dose routine varicella immunization for children <12 years of age, expanding its recommendation to two doses in 2006. Today, with widespread varicella vaccination coverage, an estimated 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections are now uncommon, health care providers (HCPs) may not recognize varicella infections and may prescribe inappropriate treatment.

Methods

An online survey of HCPs was conducted to assess recognition and management of varicella infections. Responses to eight varicella vignettes describing patients with varying varicella symptoms were analyzed and descriptive analyses performed. Stratified analysis comparing responses of those licensed before and in/after 1996 was also performed.

Results

153 HCPs (50 nurse practitioners, 103 doctors) completed the survey. Mean age of respondents was 44 years. 62% were female, and 82% were licensed before 1996. Varicella infection was correctly diagnosed 79% of the time. HCPs correctly recognized uncomplicated varicella vignettes 85% of the time versus 61% of the time for complicated varicella vignettes. Antibiotics were recommended 17% of the time and antivirals 18% of the time, of which 25% and 69% (respectively) were not appropriate per guidelines. HCPs licensed before 1996 were better able to recognize varicella compared to those licensed later, but prescribed more antimicrobials medications to treat varicella.

Conclusions

Although most HCPs recognized varicella infection, a sizable proportion could not recognize cases with complications, and some of the varicella cases were inappropriately treated with antibiotics and/or antivirals. Additional HCP training and high vaccination coverage are important strategies to avoid inaccurate diagnoses and minimize unnecessary exposure to antimicrobial/antiviral therapies.

Atypical anti-NMDA receptor encephalitis associated with varicella zoster virus infection

The triggering effect of herpes simplex virus infection on the development of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is now well established. However, there are very few reports that has linked a varicella zoster virus (VZV) reactivation with anti-NMDAR encephalitis. In this report, we describe a case of a 57-year-old man presented with atypical clinical presentation of anti-NMDAR encephalitis with gait ataxia, complete ophtalmoplegia, and abolished reflexes followed by drowsiness and confusion. Initial diagnosis of Bickerstaff's brainstem encephalitis was suspected. Few days later, the patient developed herpes zoster in a localized right T1-T2 dermatome. Cerebrospinal fluid (CSF) polymerase chain reaction (PCR) for VZV was negative. CSF anti-NMDA antibodies were proved positive. A diagnosis of anti-NMDAR encephalitis with concomitant VZV skin reactivation was retained. Favorable outcome with combined antiviral treatment and immunomodulatory therapy was observed. Concomitant VZV reactivation with autoimmune encephalitis is possible. Prognosis and therapeutic options in this rare condition remain to be clarified.

Primary Varicella or Herpes Zoster? An Educational Case Report From the Primary Care Clinic

Varicella-zoster virus is a pathogenic virus that can present itself as a primary infection or secondary infection, also known as herpes zoster. Recently, there has been a re-emergence of this vaccine-preventable disease due to gaps in vaccination. Primary varicella in immunocompetent adults is highly uncommon, and it could result in severe complications within this population. Given this delicate scenario, family physicians should be well trained to recognize the characteristic cutaneous lesions of varicella and dictate adequate management for these patients to obtain the best possible outcome and prevent life-threatening complications.

We present the case of a 43-year-old immunocompetent woman with the onset of a generalized pruritic dermatosis characterized primarily by the presence of macules, vesicles, and crusts. The patients' lesions were compatible with primary varicella, and serological studies confirmed the diagnosis. Given the absence of acute complications in this individual, supportive treatment and close follow-up were the therapeutic modalities. This article focuses on the educational discussion of the primary differential diagnosis, evaluation for possible complications, and management of this uncommon clinical scenario. We also reinforce the importance of immunization in preventing re-emergent diseases as a critical element within primary care management.

Herpes zoster and simplex reactivation following COVID-19 vaccination: new insights from a vaccine adverse event reporting system (VAERS) database analysis

BACKGROUND

A few cases of Herpes Zoster and Simplex reactivation following COVID-19 immunization have been recently described, but the real extent of this suspected adverse event has not been elucidated yet.

METHODS

We performed a nested case/control study by using the U.S. Vaccine Adverse Event Reporting System database. We carried out a case-level clinical review of all Herpes reactivation cases following the administration of COVID-19 vaccines. For cases and controls, significance was set at P = 0.05, differential risk of reporting was assessed for each vaccine as reporting odds ratio and incidence was estimated based on the total number of vaccine doses administered.

RESULTS

Of 6,195 cases included in the analysis (5,934 and 273 reporting Herpes Zoster and Herpes Simplex, respectively) over 90% were non-serious. We found a slightly higher risk of reporting both for Zoster (ROR = 1.49) and Simplex (ROR = 1.51) infections following the Pfizer-BioNTech vaccine. The estimated incidence was approximately 0.7/100,000 and 0.03/100,000 for Zoster and Simplex, respectively.

CONCLUSIONS

The paucity of cases (almost all of non-serious nature) makes the potential occurrence of this adverse effect negligible from clinical standpoints, thus supporting the good safety profile of the COVID-19 vaccination, which remains strongly recommended.

Bioinformatic analyses suggest augmented interleukin-17 signaling as the mechanism of COVID-19-associated herpes zoster

Herpes zoster results from latent varicella zoster virus reactivation in the dorsal root ganglia, causing blistering rash along the dermatomal distribution and post-herpetic neuralgia. Increasing studies indicated that there may be a correlation between herpes zoster and COVID-19. Nevertheless, the detailed pathophysiological mechanism is still unclear. We used bioinformatic analyses to study the potential genetic crosstalk between herpes zoster and COVID-19. COVID-19 and herpes zoster were associated with a similar subset of genes involved in "cytokine-cytokine receptor interaction," "Jak-STAT signaling pathway," and "IL-17 signaling pathway," including TNF, IL10, ESR1, INFG, HLA-A, CRP, STAT3, IL6, IL7, and IL17A. Protein-protein interaction network assay showed that the combined gene set indicated a raised connectivity as compared to herpes zoster or COVID-19 alone, particularly the potentiated interactions with APOE, ARSA, CCR2, CCR5, CXCL13, EGFR, GAL, GP2, HLA-B, HLA-DRB1, IL5, TECTA, and THBS1, and these genes are related to "cytokine-cytokine receptor interaction". Augmented Th17 cell differentiation and the resulting enhanced IL-17 signaling were identified in both COVID-19 and herpes zoster. Our data suggested aberrant interleukin-17 signaling as one possible mechanism through which COVID-19 could raise the risk of herpes zoster.

Atypical Presentation of Aseptic Meningitis Due to Varicella Zoster: A Case Report

Introduction

Varicella zoster virus (VZV) meningitis is primarily an infection of the immuno-compromised. However, it can also affect immunocompetent individuals. Reactivation of VZV typically presents with a distinct dermatomal rash suggestive of varicella zoster, but there have also been reports of VZV meningitis presenting without a rash.

Case Report

We describe a case of VZV meningitis in a healthy, 30-year-old male presenting to the emergency department shortly after receiving his first coronavirus disease 2019 vaccination. He was treated with intravenous acyclovir and then discharged home on oral valacyclovir.

Conclusion

Emergency physicians should consider aseptic meningitis in immunocompetent patients presenting with atypical headaches in this population.

Toll-like Receptors in Viral Encephalitis

Viral encephalitis is a rare but serious syndrome. In addition to DNA-encoded herpes viruses, such as herpes simplex virus and varicella zoster virus, RNA-encoded viruses from the families of Flaviviridae, Rhabdoviridae and Paramyxoviridae are important neurotropic viruses. Whereas in the periphery, the role of Toll-like receptors (TLR) during immune stimulation is well understood, TLR functions within the CNS are less clear. On one hand, TLRs can affect the physiology of neurons during neuronal progenitor cell differentiation and neurite outgrowth, whereas under conditions of infection, the complex interplay between TLR stimulated neurons, astrocytes and microglia is just on the verge of being understood. In this review, we summarize the current knowledge about which TLRs are expressed by cell subsets of the CNS. Furthermore, we specifically highlight functional implications of TLR stimulation in neurons, astrocytes and microglia. After briefly illuminating some examples of viral evasion strategies from TLR signaling, we report on the current knowledge of primary immunodeficiencies in TLR signaling and their consequences for viral encephalitis. Finally, we provide an outlook with examples of TLR agonist mediated intervention strategies and potentiation of vaccine responses against neurotropic virus infections.

First case report of pulmonary embolism with Zoster Sine Herpete

Background

Varicella-Zoster Virus (VZV) infection is known to cause coagulation abnormalities leading to pulmonary embolism and ischemic strokes. The incidence of vascular and thrombotic complications with Zoster Sine Herpete has been reported very infrequently in the medical literature.

Case presentation

A 32-year-old man with no significant past medical history presented to Emergency Room with right-sided facial weakness and headache. We saw no rash on physical examination. A sub-segmental pulmonary embolus was found on C.T. angiography of the chest. VZV was detected on Lumbar Puncture studies. The patient responded well to anti-viral treatment and was discharged home without any complications.

Conclusion

The suspicion of thrombo-embolic complications should be high with Zoster Sine Herpete. Screening for coagulopathies and timely initiation of anticoagulation should be carried out in appropriate clinical settings.

Complete recovery of herpes zoster radiculopathy based on electrodiagnostic study: A case report

BACKGROUND

Herpes zoster is a painful infectious disease caused by the varicella zoster virus. Herpes zoster radiculopathy, which is a type of segmental zoster paresis, can complicate the disease and cause motor weakness. This complication should be considered when a patient with a rash complains of acute-onset motor weakness, and the diagnosis can be verified via electrodiagnostic study.

CASE SUMMARY

A 64-year-old female with a history of asthma presented to the emergency department with stabbing pain, an itching sensation, and a rash on the right anterior shoulder that had begun 5 d prior. Physical examination revealed multiple erythematous grouped vesicles in the right C4-5 and T1 dermatome regions. Because herpes zoster was suspected, the patient immediately received intravenous acyclovir. On the third hospital day, she complained of motor weakness in the right upper extremity. Magnetic resonance imaging of the cervical spine revealed mild intervertebral disc herniation at C4-C5 without evidence of nerve root compression. On the 12^th hospital day, electrodiagnostic study revealed right cervical radiculopathy, mainly in the C5/6 roots. Six months later, monoparesis resolved, and follow-up electrodiagnostic study was normal.

CONCLUSION

This case emphasizes that clinicians should consider the possibility of post-herpetic paresis, such as herpes zoster radiculopathy, and that electrodiagnostic study is useful for diagnosis and follow-up.

Estimated Public Health Impact of the Recombinant Zoster Vaccine

OBJECTIVE

To investigate the potential public health impact of adult herpes zoster (HZ) vaccination with the adjuvanted recombinant zoster vaccine (RZV) in the United States in the first 15 years after launch.

METHODS

We used a publicly available model accounting for national population characteristics and HZ epidemiological data, vaccine characteristics from clinical studies, and anticipated vaccine coverage with RZV after launch in 2018. Two scenarios were modeled: a scenario with RZV implemented with 65% coverage after 15 years and a scenario continuing with zoster vaccine live (ZVL) with coverage increasing 10% over the same period. We estimated the numbers vaccinated, and the clinical outcomes and health care use avoided yearly, from January 1, 2018, to December 31, 2032. We varied RZV coverage and investigated the associated impact on HZ cases, complications, and health care resource use.

RESULTS

With RZV adoption, the numbers of individuals affected by HZ was predicted to progressively decline with an additional 4.6 million cumulative cases avoided if 65% vaccination with RZV was reached within 15 years. In the year 2032, it was predicted that an additional 1.3 million physicians' visits and 14.4 thousand hospitalizations could be avoided, compared with continuing with ZVL alone. These numbers could be reached 2 to 5 years earlier with 15% higher RZV vaccination rates.

CONCLUSION

Substantial personal and health care burden can be alleviated when vaccination with RZV is adopted. The predicted numbers of HZ cases, complications, physicians' visits, and hospitalizations avoided, compared with continued ZVL vaccination, depends upon the RZV vaccination coverage achieved.

Uncommon presentation and complications of herpes zoster infection involving the cervical, vagus and accessory nerves which caused a delay in diagnosis and treatment

A 70-year-old man with a history of invasive anal squamous cell carcinoma treated with excision and chemoradiation presented to the emergency department with right-sided neck pain and submandibular lymphadenopathy. CT imaging of the head and neck was unrevealing. The patient eventually developed cranial nerves X and XI dysfunction, manifesting as severe vocal cord paralysis (dysphonia), dysphagia, asymmetric palate elevation/deviation and trapezius muscle atrophy, in addition to scalene muscle atrophy. After an extensive workup, the patient's symptoms were determined to be due to sequelae of varicella zoster infection, which was confirmed with antibody titers. The patient's dysphagia and dysphonia eventually improved with vocal cord medialisation injection and Botox injection. However, despite delayed treatment with acyclovir and valacyclovir, the patient continued to have neuropathic pain and exhibit signs of CN X and CN XI paresis, in addition to scalene muscle atrophy.

A white circular-spot pattern of iridian atrophy associated with Varicella-zoster virus and Toxoplasma gondii coinfection: a case report

Background

We report a case of white circular spots of iridian atrophy, which we will call “polka dots” pattern, as a rare ophthalmological finding associated with uveitis secondary to varicella-zoster virus and Toxoplasma gondii coinfection in a male patient in Bogotá, Colombia.

Case presentation

We present de case of a 53-year-old Colombian male patient with a diagnosis of anterior uveitis in his left eye due to varicella-zoster virus and Toxoplasma gondii coinfection documented by polymerase chain reaction analysis. He presented with multiple areas of superficial white circular spots of iridian atrophy in 360º, some with deeper atrophy where the stroma fibers were visualized and only a small punctate defect of transillumination was evident. This rare pattern of iridian atrophy has not been previously described in cases of uveitis in the literature.

Conclusions

This is the first case reporting the findings of superficial “polka dots” pattern iridian atrophy in 360° secondary to anterior uveitis due to the coinfection of a virus and a parasite. The identification of similar clinical cases may lead to early initiation of systemic treatment in these patients.

An overview of viral infections of the nervous system in the immunosuppressed

Several viruses have the capacity to cause serious infections of the nervous system in patients who are immunosuppressed. Individuals may be immunosuppressed because of primary inherited immunodeficiency, secondary immunodeficiency due to particular diseases such as malignancy, administration of immunosuppressant drugs or organ or bone marrow transplantation. The viruses capable of such opportunistic infection of the nervous system include herpes simplex virus (HSV), Varicella-Zoster virus (VZV), Cytomegalovirus (CMV), Epstein -Barr virus (EBV), Human Herpes virus type 6 (HHV-6), JC virus (JCV), enterovirus, measles virus and Covid-19. In most cases it seems likely that immunological defence mechanisms in the immunosuppressed are deficient which creates a suitable environment for certain viruses to become opportunistic in the nervous and other systems. Further research is required both to understand these opportunistic mechanisms in more detail and also to determine how many virus infections are modified by specific inborn errors of immunological responses.

[An autopsied case of severe varicella zoster virus-associated encephalomyelitis under immunosuppressant therapy]

The patient was a 40-year-old woman who was previously diagnosed with systemic lupus erythematosus and myasthenia gravis and had received prednisolone and tacrolimus for more than 7 years. In February 2017, she noticed pain in her lower back and weakness of the lower limbs, and was referred to our hospital on day 5. She had shingles in the right lower thoracic dermatomes and Brown-Séquard syndrome with right-sided dominant weakness in her lower limbs and left-sided superficial sensory disturbance below the L1 level. Varicella zoster virus (VZV)-associated myelopathy was suspected because of her symptoms and clinical findings. Despite the immediate administration of intravenous acyclovir after hospitalization, she lost consciousness and experienced a seizure related to cerebral hemorrhage in the left temporal lobe on the night of day 5. MRI showed enhanced lesions along the spinal cord and leptomeninges of the brainstem and temporal lobe. VZV-IgG and VZV-DNA were positive in the cerebrospinal fluid. Based on these clinical features and laboratory findings, she was diagnosed as VZV-associated vasculopathy and myelopathy. She subsequently had multiple cerebral infractions and hemorrhage, and developed sudden cardiopulmonary arrest on day 6, culminating in death on day 17. Autopsy showed that inflammatory mononuclear cells had infiltrated the vascular walls of the spinal cord. Immunohistochemistry revealed that some neurons and macrophages in the white matter of the spinal cord were positive for VZV. In addition, atrophic neurons, satellite cells surrounding these neurons, and infiltrating macrophages were immune-positive for VZV at the L2 dorsal root ganglia. These findings were consistent with VZV-associated vasculopathy and myelitis. Under immunosuppressive conditions, VZV can cause shingles and neuronal complications such as vasculopathy and myelitis, which are sometimes fatal despite the immediate administration of intravenous acyclovir. New treatment drugs or drugs to prevent VZV activation are desired.

Varicella-Zoster Virus infected human neurons are resistant to apoptosis

Varicella-zoster virus (VZV) is a pathogenic human herpesvirus that causes varicella (chickenpox) as a primary infection following which it becomes latent in ganglionic neurons. Following viral reactivation many years later VZV causes herpes zoster (shingles) as well as a variety of other neurological syndromes. The molecular mechanisms of the conversion of the virus from a lytic to a latent state in ganglia are not well understood. In order to gain insights into the neuron-virus interaction, we studied virus-induced apoptosis in cultures of both highly pure terminally differentiated human neurons and human fetal lung fibroblasts (HFL). It was found that (a) VZV DNA did not accumulate in infected human neurons; (b) VZV transcripts were present at lower levels at all days studied post-infection in neurons; (c) Western blot analysis showed less VZV IE 63 and very little detectable VZV gE proteins in infected neurons compared with HFL; (d) lower levels of the apoptotic marker cleaved Caspase-3 protein were detected in VZV-infected neurons compared with HFL, and higher levels of the known anti-apoptotic proteins Bcl2, Bcl-XL and also the mitochondrial MT-CO2 protein were found in VZV-infected neurons compared with uninfected cells; and (e) both the MT-CO2 protein and VZV IE 63-encoded protein were detected in infected neurons by dual immunofluorescence. These findings showed that neurons are resistant to VZV-induced apoptosis, which may have relevance to the switching of VZV from a lytic to latent ganglionic neuronal infection.

Recurrent oral ulceration: Etiology, classification, management, and diagnostic algorithm

Recurrent oral ulcerations are manifestations of a heterogeneous set of both general and more-or-less specific oral diseases due to numerous potential etiologies, including, but not limited to, infections, medications, autoimmune disease, and other systemic disease. This review discusses the pathogenesis, clinical presentation, diagnosis, and management of the common causes of recurrent oral ulceration. The following types/etiologies of recurrent oral ulceration are covered: traumatic ulceration, chemical ulceration, recurrent aphthous stomatitis, medication-related ulceration, infectious ulceration, mucocutaneous disease, and autoimmune/systemic disease. A diagnostic algorithm for recurrent oral ulceration is also presented.

Longitudinal Extensive Transverse Myelitis in an Immunocompetent Older Individual-A Rare Complication of Varicella-Zoster Virus Reactivation

Varicella-zoster virus (VZV) is a human neurotropic herpes virus that causes chickenpox in children. After becoming latent in dorsal root ganglia, it can reactivate to cause dermatological manifestations, the most common one being shingles or herpes zoster. Severe neurologic dysfunctions can occur in immunocompromised patients such as encephalitis, meningitis, myelitis and neuropathy. Longitudinal extensive transverse myelitis (LETM) is an unusual neurological complication mainly described in immunocompromised patients, with very few cases described in immunocompetent ones. We hereby report a case of VZV-induced LETM in an immunocompetent older adult—a situation rarely described in the literature. LETM is a rare complication of VZV and its pathogenesis; therapeutic interventions and prognosis are far from being fully clarified. However, a prompt diagnosis is needed to allow a rapid initialization of treatment and ensure a better outcome. Although the therapeutic lines are not clear, immunosuppressive agents may have their place in cases of unsuccessful results and/or relapses following acyclovir coupled with a well conducted methylprednisolone therapy. Further studies are highly needed to improve the current understanding of the disease course and mechanisms, and to optimize therapeutic strategies.

Improving immunization strategies in patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are susceptible to varieties of opportunistic infections due to immunological changes in the setting of their disease and drug-induced immunosuppression. Even though numerous infections can be prevented by vaccine, vaccination in IBD patients is inadequate. Data showed only 9% were vaccinated against pneumococcal infection and 28% described commonly receiving influenza vaccine. This review article discusses the recent immunizations against influenza virus; pneumococcal infection; human papilloma virus; tetanus, diphtheria and pertussis; measles, mumps and rubella; varicella zoster; and herpes zoster for individuals diagnosed with IBD and those patients with drug-related immunosuppression. In addition, this review discusses concerns about IBD patients planning to travel abroad. Immunization status and screening for opportunistic infection need to be addressed in IBD patients at the time of diagnosis and they should be vaccinated accordingly. Generally, standard vaccination strategies should be pursued in IBD patients, although live vaccines should be avoided while they are not immunocompetent.

Does Herpes Zoster Increase the Risk of Stroke and Myocardial Infarction? A Comprehensive Review

Herpes zoster (HZ) caused by varicella zoster virus (VZV) reactivation is characterized as a vesicular rash of unilateral distribution that can also cause multiple complications; such as post-herpetic neuralgia; ophthalmic zoster; and other neurological issues. VZV can also increase incident hemorrhagic or ischemic complications by causing inflammatory vasculopathy. Thus; emerging epidemiological and clinical data recognizes an association between HZ and subsequent acute strokes or myocardial infarction (MI). This study reviewed published articles to elucidate the association between HZ and cerebrovascular and cardiac events. Individuals exposed to HZ or herpes zoster ophthalmicus had 1.3 to 4-fold increased risks of cerebrovascular events. Higher risks were noted among younger patients (age < 40 years) within one year after an HZ episode. The elevated risk of CV events diminished gradually according to age and length of time after an HZ episode. The putative mechanisms of VZV vasculopathy were also discussed. Several studies showed that the development of herpes zoster and herpes zoster ophthalmicus increased the risks of stroke; transient ischemic attack; and acute cardiac events. The association between VZV infection and cardiovascular events requires further studies to establish the optimal antiviral treatment and zoster vaccination to reduce zoster-associated vascular risk

Cerebellar Ataxia in Children: A Clinical and MRI Approach to the Differential Diagnosis

: The cerebellum has long been recognized as a fundamental structure in motor coordination. Structural cerebellar abnormalities and diseases involving the cerebellum are relatively common in children. The not always specific clinical presentation of ataxia, incoordination, and balance impairment can often be a challenge to attain a precise diagnosis. Continuous advances in genetic research and moreover the constant development in neuroimaging modalities, particularly in the field of magnetic resonance imaging, have promoted a better understanding of cerebellar diseases and led to several modifications in their classification in recent years. Thorough clinical and neuroimaging investigation is recommended for proper diagnosis. This review outlines an update of causes of cerebellar disorders that present clinically with ataxia in the pediatric population. These conditions were classified in 2 major groups, namely genetic malformations and acquired or disruptive disorders recognizable by neuroimaging and subsequently according to their features during the prenatal and postnatal periods.

Encephalitis associated with Zika virus infection and reactivation of the varicella-zoster virus in a Brazilian child

We report a case of encephalitis associated with Zika virus infection and reactivation of varicella-zoster virus in the central nervous system of a Brazilian child. This case raises the possibility that reactivation of the latent varicella-zoster virus may be a mechanism of neurological impairment induced by acquired Zika virus infection.

Neurologic Complications of Transplantation

PURPOSE OF REVIEW

This article describes the diagnosis and management of neurologic problems during hematopoietic cell and solid organ transplantation using time elapsed since transplantation as a guide to expected complications, including drug toxicities, infections, strokes, autoimmune phenomena, disease recurrence, and secondary neoplasms.

RECENT FINDINGS

Growing clinical experience in the neurology of transplantation has led to appreciation of the diverse clinical and radiographic spectrum of calcineurin inhibitor-related posterior reversible encephalopathy syndrome (PRES) and progressive multifocal leukoencephalopathy. Novel autoimmune phenomena illustrate the delicate balance between adequate immunosuppression and necessary host inflammatory defenses that can lead to organ rejection. The spectrum of infectious complications has changed with the evolution of new conditioning regimens.

SUMMARY

Neurologic problems remain an important source of morbidity and mortality, both in the immediate transplantation period and for years after the procedure. As perioperative management has reduced the incidence of acute infections, graft versus host disease, and organ rejection, problems of long-term survivors require neurologic input into multidisciplinary management of chronic neurologic conditions impacting quality of life.

Varicella zoster meningitis: an atypical case of zoster reactivation in immunocompetent young adult

Varicella virus is a neurotropic virus that can reactivate later in life to cause zoster or shingles. Typically, it affects elderly, immunocompromised population. We report an unusual case of an immunocompetent young adult presenting with occipital headache and zoster rash, without preherpetic and postherpetic neuralgia, who was diagnosed with varicella meningitis on Polymerase chain reaction (PCR). He was treated with intravenous acyclovir and later discharged on famciclovir. Diagnosis of varicella meningitis is difficult in the absence of typical features of zoster rash and requires high index of suspicion. Rapid diagnostic tests including varicella PCR and antithecal antibody testing can help in the confirmation of varicella zoster meningitis.

Varicella-Zoster Virus Gastritis: Case Report and Review of the Literature

We report varicella-zoster virus (VZV) gastritis in a 70-year-old woman postchemotherapy for lymphoma, presenting with abdominal pain, vomiting, and delirium without rash. A gastric biopsy demonstrated viral inclusions but posed a diagnostic challenge as immunohistochemistry for cytomegalovirus and herpes simplex virus were negative, and VZV immunohistochemistry was not available. The patient developed a vesicular rash 7 days after her symptoms began. Molecular testing of the gastric biopsy and a skin swab both confirmed VZV infection. She also had probable involvement of her liver and pancreas based on imaging and serum chemistry, and possible central nervous system involvement. She recovered with appropriate antiviral therapy but later developed a postherpetic neuralgia, and chronic intrahepatic biliary strictures; liver biopsy demonstrated a cholangiopathy of uncertain etiology. A literature review of the pathogenesis, epidemiology and sequelae of VZV infection is included.

Other facial neuralgias

Premise In this article we review some lesser known cranial neuralgias that are distinct from trigeminal neuralgia, trigeminal autonomic cephalalgias, or trigeminal neuropathies. Included are occipital neuralgia, superior laryngeal neuralgia, auriculotemporal neuralgia, glossopharyngeal and nervus intermedius neuralgia, and pain from acute herpes zoster and postherpetic neuralgia of the trigeminal and intermedius nerves. Problem Facial neuralgias are rare and many physicians do not see such cases in their lifetime, so patients with a suspected diagnosis within this group should be referred to a specialized center where multidisciplinary team diagnosis may be available. Potential solution Each facial neuralgia can be identified on the basis of clinical presentation, allowing for precision diagnosis and planning of treatment. Treatment remains conservative with oral or topical medication recommended for neuropathic pain to be tried before more invasive procedures are undertaken. However, evidence for efficacy of current treatments remains weak.

Can pontine trigeminal T2-hyperintensity suggest herpetic etiology of trigeminal neuralgia?

BACKGROUND

Trigeminal neuralgia (TN) is usually classified into two different categories: idiopathic and secondary. We have investigated the frequency of brainstem pontine lesions in patients with idiopathic TN without multiple sclerosis (MS) or stroke, and their association with herpes zoster (HZ) infection.

METHODS

Brain magnetic resonance imaging (MRI) studies of 28 patients with TN were retrospectively reviewed.

RESULTS

We found seven patients with clinical suspicion of HZ infection and pontine T2 hyperintense lesions, associated with nerve atrophy in one case. Fifteen patients had a neurovascular conflict (NVC) without brainstem involvement, two of them associated with trigeminal atrophy, while four patients had only volumetric reduction of the nerve. In all patients MRI findings were ipsilateral to the side of TN.

CONCLUSIONS

Pontine T2 hyperintensities could be considered as a MRI sign of TN in patients without NVCs. This "trigeminal pontine sign" (TPS) is frequently found in association with herpetic infections.

Definition and management of varicella zoster virus-associated meningoradiculitis: a case report

Background

The varicella zoster virus affects the central or peripheral nervous systems upon reactivation, especially when cell-mediated immunity is impaired. Among varicella zoster virus-related neurological syndromes, meningoradiculitis is an ill-defined condition for which clear management guidelines are still lacking. Zoster paresis is usually considered to be a varicella zoster virus-peripheral nervous system complication and treated with oral antiviral therapy. Yet in the literature, the few reported cases of herpes zoster with mild cerebral spinal fluid inflammation were all considered meningoradiculitis and treated using intravenous antiviral drugs, despite absence of systemic signs of meningitis. Nevertheless, these two clinical pictures are very similar.

Case presentation

We report the case of an alcohol-dependent elderly Caucasian man presenting with left lower limb zoster paresis and mild cerebral spinal fluid inflammation, with favorable outcome upon IV antiviral treatment. We discuss interpretation of liquor inflammation in the absence of clinical meningitis and implications for the antiviral treatment route.

Conclusion

From this case report we suggest that varicella zoster virus-associated meningoradiculitis should necessarily include meningitis symptoms with the peripheral neurological deficits and cerebral spinal fluid inflammation, requiring intravenous antiviral treatment. In the absence of (cell-mediated) immunosuppression, isolated zoster paresis does not necessitate spinal tap or intravenous antiviral therapy.

Postherpetic neuralgia: epidemiology, pathophysiology, and pain management pharmacology

Herpes zoster, also known as shingles, is a distinctive clinical condition caused by the reactivation of latent varicella zoster (chickenpox) virus following an initial infection. Approximately 1 million cases of herpes zoster occur annually in the US, and one in every three people develops herpes zoster during their lifetime. Postherpetic neuralgia is a neuropathic pain syndrome characterized by pain that persists for months to years after resolution of the herpes zoster rash. It stems from damage to peripheral and central neurons that may be a byproduct of the immune/inflammatory response accompanying varicella zoster virus reactivation. Patients with postherpetic neuralgia report decreased quality of life and interference with activities of daily living. Approaches to management of postherpetic neuralgia include preventing herpes zoster through vaccination and/or antiviral treatment, and administering specific medications to treat pain. Current guidelines recommend treatment of postherpetic neuralgia in a hierarchical manner, with calcium channel α2-δ ligands (gabapentin and pregabalin), tricyclic antidepressants (amitriptyline, nortriptyline, or desipramine), or topical lidocaine patches as first-line drugs. The safety and tolerability of pharmacologic therapies for pain are important issues to consider as postherpetic neuralgia affects primarily an older population. Patients should be educated on appropriate dosing, titration if applicable, the importance of adherence to treatment for optimal effectiveness, and possible side effects. Health-care professionals play a key role in helping to ameliorate the pain caused by postherpetic neuralgia through early recognition and diligent assessment of the problem; recommending evidence-based treatments; and monitoring treatment adherence, adverse events, responses, and expectations. Nurse practitioners are especially crucial in establishing communication with patients and encouraging the initiation of appropriate pain-relieving treatments.

Postherpetic neuralgia

Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. This article is about postherpetic neuralgia (PHN), a devastating complication following reactivation of the varicella-zoster virus. The answer offers an explanation for why this pain occurs, and cites literature regarding its incidence and treatment.

Varicella-Zoster Virus Vasculopathy: The Growing Association Between Herpes Zoster and Strokes

Varicella-zoster virus (VZV) is herpes virus that after its reactivation from nerve ganglia to cause herpes zoster may lead to a variety of neurologic complications, including encephalitis, meningitis, retinal necrosis or myelitis. In addition, VZV can spread to arteries in the central nervous system and cause hemorrhagic or ischemic complications due to an inflammatory vasculopathy. In fact, there is a growing epidemiological and clinical recognition that there is an association between VZV reactivation and subsequent strokes. Herein, we present a case of an immune compromised individual with reactivation of VZV causing dermatomal herpes zoster followed by multifocal vasculopathy. We also review the literature to highlight key aspects of VZV-associated vasculopathy.

Interferon Gamma Prolongs Survival of Varicella-Zoster Virus-Infected Human Neurons In Vitro

Infection of human neurons in vitro with varicella-zoster virus (VZV) at a low multiplicity of infection does not result in a cytopathic effect (CPE) within 14 days postinfection (dpi), despite production of infectious virus. We showed that by 28 dpi a CPE ultimately developed in infected neurons and that interferon gamma inhibited not only the CPE but also VZV DNA accumulation, transcription, and virus production, thereby prolonging the life of VZV-infected neurons.

Cell-fusion events induced by α-herpesviruses

ABSTRACT 

Enveloped viruses encode proteins that can induce cell fusion to allow spread of infection without exposure to immune surveillance. In this review, we discuss cell fusion events caused by neurotropic α-herpesviruses. Syncytia (large, multinucleated cells) are clinically indicative of α herpesvirus infections, and peripheral neuropathies are clinical hallmarks. We examine the viral and cellular factors required for cell fusion, as well as mutations which confer a more aggressive ‘hypersyncytial’ phenotype. Finally, we consider the causes of fusion events in infected neurons, and the implications for neuronal dysfunction and pathophysiology.

Axonal spread of neuroinvasive viral infections

Neuroinvasive viral infections invade the nervous system, often eliciting serious disease and death. Members of four viral families are both neuroinvasive and capable of transmitting progeny virions or virion components within the long neuronal extensions known as axons. Axons provide physical structures that enable viral infection to spread within the host while avoiding extracellular immune responses. Technological advances in the analysis of in vivo neural circuits, neuronal culturing, and live imaging of fluorescent fusion proteins have enabled an unprecedented view into the steps of virion assembly, transport, and egress involved in axonal spread. In this review we summarize the literature supporting anterograde (axon to cell) spread of viral infection, describe the various strategies of virion transport, and discuss the effects of spread on populations of neuroinvasive viruses.

Relief of pain induced by varicella-zoster virus in a rat model of post-herpetic neuralgia using a herpes simplex virus vector expressing enkephalin

Acute and chronic pain (post-herpetic neuralgia or PHN) are encountered in patients with herpes zoster that is caused by reactivation of varicella-zoster virus (VZV) from a state of neuronal latency. PHN is often refractory to current treatments, and additional strategies for pain relief are needed. Here we exploited a rat footpad model of PHN to show that herpes simplex virus (HSV) vector-mediated gene delivery of human preproenkephalin (vHPPE) effectively reduced chronic VZV-induced nocifensive indicators of pain. VZV inoculated at the footpad induced prolonged mechanical allodynia and thermal hyperalgesia that did not develop in controls or with ultraviolet light-inactivated VZV. Subsequent footpad administration of vHPPE relieved VZV-induced pain behaviors in a dose-dependent manner for extended periods, and prophylactic vector administration prevented VZV-induced pain from developing. Short-term pain relief following low-dose vHPPE administration could be effectively prolonged by vector re-administration. HPPE transcripts were increased three- to fivefold in ipsilateral ganglia, but not in the contralateral dorsal root ganglia. VZV hypersensitivity and its relief by vHPPE were not affected by peripheral delivery of opioid receptor agonist or antagonist, suggesting that the efficacy was mediated at the ganglion and/or spinal cord level. These results support further development of ganglionic expression of enkephalin as a novel treatment for the pain associated with Zoster.