Varicella-Zoster virus cause

Ota K, Kim V, Lavi S, Ford-Jones EL, Tipples G, Scolnik D, Tellier R. Vaccine-strain varicella zoster virus causing recurrent herpes zoster in an immunocompetent 2-year-old child. Pediatr Infect Dis J 2008 27 847-8. 

Viruses are a common cause of CAP in children (-65%) and much less common in adults ( 15%).8 Viruses often associated with pneumonia in adults include influenza A and B and adenoviruses, whereas less common causes include rhinoviruses, enteroviruses, cytomegalovirus, varicella-zoster virus, herpes simplex virus, and others. In children, viral pneumonia is caused more commonly by respiratory syncyntial virus, influenza A virus, and parainfluenza virus. The viruses associated with CAP in adults are much less common causes of pneumonia in children. 

Varicella-zoster virus immunoglobulin Human Specificity for causative agent of chicken pox... 

The specific antiviral agents used to treat cutaneous infections caused by herpes simplex and varicella zoster viruses are discussed in Chapter 50. 

Chickenpox or varicella is caused by the varicella zoster virus (VZV). Varicella vaccine is indicated for active immunisation against varicella in healthy subjects and their susceptible healthy close contacts from the age of 12 months onwards. 

Acyclovir (ACV) is not a true nucleoside, because the guanine residue is attached to an open-chain structure, but it mimics deoxyribose well enough for the compound to be accepted as a substrate by a thymidine kinase specified by certain herpes-type viruses. The normal thymidine kinase in mammalian cells does not recognize ACV as a substrate, however, so only virus-infected cells convert ACV to its monophosphate. Once the first phosphate has been added, the second phosphate is added by cellular guanylate kinase several other cellular kinases can add the third phosphate. The triphosphate is a more potent inhibitor of the viral DNA polymerases than of cellular DNA polymerases and also inactivates the former but not the latter. The net result is that ACV has been an effective treatment of, and prophylaxis for, genital herpes. Also it can result in dramatic relief of pain associated with shingles caused by reactivation of latent varicella-zoster virus, and has been successful in many patients with herpes encephalitis. 

Antiviral Efficacy and Clinical Use. Vidarabine (Vira-A) was the first systemic agent used to treat herpesvirus infections, including CMV, herpes simplex virus, and varicella-zoster virus.42 In the past, this drug was administered by continuous intravenous infusion to treat severe systemic infections caused by these viruses, but systemic use of vidarabine has been replaced by safer and less toxic agents. Vidarabine is currently used primarily to treat local viral infections of the eye (e.g., herpes simplex keratoconjunctivitis) it is applied topically by ophthalmic ointment to treat these infections. 

Herpes describes a family of viruses. In general, the term herpes is most closely associated with the conditions of oral and genital herpes, which are caused by the herpes simplex viruses (HSV). Other frequently encountered herpes viruses include the Epstein-Barr virus (EBV, which causes mononucleosis), cytomegalovirus (CMV, which causes various infections of the eyes, liver, colon, and lungs), and varicella zoster virus (VZV, which causes chicken pox and shingles). 

Herpesviruses range in size from 120 to 300 nm and have DNA genomes and outer lipid membranes (envelopes). As enveloped viruses, herpesviruses are sensitive to drying and adverse conditions. Herpesviruses are spread by inoculation of susceptible mucous membranes or direct cell-to-cell contact. Over 100 herpesviruses have been identified, but only 5 cause human eye infections with any frequency herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus. Herpesviruses can cause blepharitis, conjunctivitis, epithelial and stromal keratitis, uveitis, retinitis, and ARN. HSV-1 is the most frequent cause of primary and recurrent eye disease. The host immime system influences the rates of reactivation. Immimocompromised patients tend to have more frequent reactivations and more severe disease manifestations. The strain of virus also affects the... 

Chickenpox in infancy and shingles in adults are caused by the same varicella-zoster virus. Very rarely and almost exclusively in immunosuppressed patients, concomitant hepatitis can occur with pronounced (mainly focal) hepatocellular necrosis, sometimes even with a fatal course. (37) Leucocytic portal and periportal infiltration can spread to the blood vessels and bile capillaries. Intranuclear inclusion bodies are present (s. fig. 23.2). Diagnosis is based on increased GPT, GOT, GDH and y-GT values as well as the presence of varicella IgM antibodies alternatively, pathogens can also be demonstrated in cultures. In children, a differential diagnosis of Reye s syndrome must be considered. As therapy in a severe course, aciclovir is indicated. (38-43)... 

Chickenpox is caused by varicella-zoster virus. Every year, about 3.5 million people in the United Slates, mostly children. contract chickenpox. The incidence peaks between 3 and 9 years of age. Chickenpox causes a generalized rash, with 300 to 500 blister-like lesions occurring on the scalp, face, and trunk. Symptoms include loss of appetite, malaise, and headache. The disease is usually benign but can lead lo bacterial superinfection, pneumonia, encephalitis, and Reye s syndrome. About 5(1 to 100 previously healthy children die of the diseu.se. About 2% of all cases occur in adults, w ho have more serious symptoms than children have. 

Varicella-zoster virus (VZV) Enveloped, isocahedral particles 1 50 nm in diameter Causes chickenpox in children virus remains dormant in any dorsal root ganglion of the CNS release of immune control in the elderly stimulates reactivation resulting in shingles... 

The most serious clinical manifestation of CMV disease and the leading cause of infectious death in HSCT recipients is interstitial pneumonia (IP), which is associated with an 85% mortality rate if untreated. This clinical syndrome manifests as fever, dyspnea, hypoxia, nonproductive cough, and diffuse pulmonary infiltrates. As many as 40% of allogeneic HSCT patients will develop IP of these patients with IP, up to 40% of cases are the result of CMV. IP also may result from other infectious (P. jiroveci, varicella-zoster virus) and noninfectious causes (pulmonary damage by radiation and chemotherapy). ... 

Varicella is a highly contagious disease caused by varicella-zoster virus. The clinical illness is characterized by the appearance of successive waves of pruritic vesicles that rapidly crust over. Malaise and fever are common and last for 2 to 3 days. The virus remains dormant in the dorsal ganglia and reactivates as herpes zoster, also known as shingles. Although the exact stimulus for reactivation is unknown, a decrease in varicella-specific cell-mediated immunity associated with age or immunosuppression appears to be necessary but not sufficient for reactivation. 

Viral retinitis may be caused by herpes simplex virus, cytomegalovirus (CMV), adenovirus, and varicella zoster virus. With the highly active antiretroviral therapy (see Chapter 50), CMV retinitis does not appear to progress when specific anti-CMV therapy is discontinued, but some patients develop an immune recovery uveitis. Treatment usually involves long-term parenteral administration of antiviral drugs. Intravitreal administration of ganciclovir has been found to be an effective... 

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