Complications of Varicella Zoster Virus Reactivation.
ABSTRACT Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which virus becomes latent in ganglionic neurons along the entire neuraxis. With advancing age or immunosuppression, cell-mediated immunity to VZV declines and virus reactivates to cause zoster (shingles), which can occur anywhere on the body. Skin lesions resolve within 1-2 weeks, while complete cessation of pain usually takes 4-6 weeks. Zoster can be followed by chronic pain (postherpetic neuralgia), cranial nerve palsies, zoster paresis, meningoencephalitis, cerebellitis, myelopathy, multiple ocular disorders and vasculopathy that can mimic giant cell arteritis. All of the neurological and ocular disorders listed above may also develop without rash. Diagnosis of VZV-induced neurological disease may require examination of cerebrospinal fluid (CSF), serum and/ or ocular fluids. In the absence of rash in a patient with neurological disease potentially due to VZV, CSF should be examined for VZV DNA by PCR and for anti-VZV IgG and IgM. Detection of VZV IgG antibody in CSF is superior to detection of VZV DNA in CSF to diagnose vasculopathy, recurrent myelopathy, and brainstem encephalitis. Oral antiviral drugs speed healing of rash and shorten acute pain. Immunocompromised patients require intravenous acyclovir. First-line treatments for post-herpetic neuralgia include tricyclic antidepressants, gabapentin, pregabalin, and topical lidocaine patches. VZV vasculopathy, meningoencephalitis, and myelitis are all treated with intravenous acyclovir.
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ABSTRACT: Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. It is unclear why human neurons infected in vitro with VZV at low multiplicity of infection do not exhibit a cytopathic effect (CPE) even though all VZV genes are transcribed, VZV proteins from all kinetic classes are translated and minimal infectious virus is produced. Here, we show that the lack of VZV-induced CPE correlates with the low abundance of viral DNA.Virology. 06/2014; 458-459C:1-3.
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ABSTRACT: The development of neurological complications due to varicella zoster virus (VZV) reactivation is relatively uncommon, particularly in the case of immunocompetent patients. Only a few cases have been described in the literature, most of which involved adult or elderly patients.Clinical presentation: Two days after his pediatrician had diagnosed herpes zoster and prescribed oral acyclovir 400 mg three times a day, a 14-year-old boy was admitted to our hospital because of mild fever, severe headache, slowness, drowsiness and vomiting. A cerebrospinal fluid examination was performed and showed an increased protein concentration (95 mg/dL), normal glucose level (48 mg/dL; blood glucose level, 76 mg/dL) and lymphocytic pleocytosis (1,400 lymphocytes/muL), and VZV DNA was detected by means of polymerase chain reaction (1,250 copies/mL). The results of immunological screening for HIV, lymphocyte subpopulation counts, serum immunoglobulin and complement (C3 and C4) levels, vaccine responsiveness and lymphocytes stimulation tests were unremarkable. Acyclovir was administered intravenously at a dose of 10 mg/kg three times a day and continued for 10 days. The therapy was highly effective and the patient's clinical condition rapidly improved: fever disappeared after two days, and all of the signs and symptoms of neurological involvement after four days. The skin lesions resolved in about one week, and no pain or dysesthesia was ever reported. Given the favourable evolution of the illness, the child was discharged without further therapy after the 10-day treatment. The findings of a magnetic resonance examination immediately after the discontinuation of the antiviral therapy were normal, and a control examination carried out about four weeks later did not find any sign or symptom of disease. VZV reactivation can also lead to various neurological complications in immunocompetent children. Prompt therapy with acyclovir and the integrity of the immune system are important in conditioning outcome, but other currently unknown factors probably also play a role.Italian Journal of Pediatrics 11/2013; 39(1):72. · 1.24 Impact Factor
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ABSTRACT: 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.Gene Therapy advance online publication, 15 May 2014; doi:10.1038/gt.2014.43.Gene therapy 05/2014; · 4.75 Impact Factor