Varicella zoster update on Vaccination

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Varicella zoster update on Vaccination

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Varicella zoster update on Vaccination

  1. 1. Varicella Zoster Vaccination update Dr.T.V.Rao MD4/13/2012 Dr.T.V.Rao MD 1
  2. 2. Herpesviridae • The Herpesviridae are a large family of DNA viruses that cause diseases in animals, including humans The family name is derived from the Greek word herpein ("to creep"), referring to the latent, relapsing infections typical of this group of viruses. Herpesviridae can cause latent or lytic infections.4/13/2012 Dr.T.V.Rao MD 2
  3. 3. Herpes Viruses DNA group • Most important Human Pathogens • Wide Host cell range • Life Long Infection – Periodic reactivation • Immunocompromised • Large number of genes, • Some viruses susceptible to treatment.4/13/2012 Dr.T.V.Rao MD 3
  4. 4. Varicella Zoster4/13/2012 Dr.T.V.Rao MD 4
  5. 5. Properties of Virus.• Like Herpes Virus• Icosahedrons shape ds DNA4/13/2012 Dr.T.V.Rao MD 5
  6. 6. Properties of Herpes Viruses. • Spherical in Shape • Icosahedral 150 to 200 nm in size • Genome – Double stranded DNA Linear • Envelope contains Glycoproteins4/13/2012 Dr.T.V.Rao MD 6
  7. 7. 4/13/2012 Dr.T.V.Rao MD 7
  8. 8. Varicella Zoster• Varicella -Chicken pox.• Contagious Disease• Mainly Children Generalized Vesicular eruptions on Skin and Mucous membranes Severe manifestations in Adults and Immune compromised.4/13/2012 Dr.T.V.Rao MD 8
  9. 9. Herpes viruses• Varicella-zoster virus (Human herpes virus 3)• Transmitted by the respiratory route• Causes pus-filled vesicles• Virus may remain latent in dorsal root ganglia4/13/2012 Dr.T.V.Rao MD 9 Figure 21.10a
  10. 10. HERPES VARICELLA ZOSTER HVZ• Causes chicken pox -fever + characteristic rash• variable incubation period 14-21 days• usually mild in children and more severe in adults• complications – secondary infection - uncommon – varicella pneumonia – secondary bacterial pneumonia S aureus & pneumococci – post-infectious encephalitis – generalized varicella (in immunocompromised patients) – congenital and neonatal varicella 4/13/2012 Dr.T.V.Rao MD 10
  11. 11. Herpes Zoster• Rash Limited to Distribution of Single Sensory Ganglion In Adults and immune compromised patients• Reactivation of latent HHV-3 releases viruses that move along peripheral nerves to skin.4/13/2012 Dr.T.V.Rao MD 11
  12. 12. Clinical Findings.• Varicella, Incubation 10-20 days• Fever, Malaise• Rash Trunk –Face –Limbs – Buccal and Pharyngeal mucosa• Lesions at all stages Macules, Papules, Vesicles, Crusts,May last 5 days, Hundreds of eruptions.4/13/2012 Dr.T.V.Rao MD 12
  13. 13. HERPES VARICELLA ZOSTER HVZ• Causes chicken pox -fever + characteristic rash• variable incubation period 14-21 days• usually mild in children and more severe in adults• complications – secondary infection - uncommon – varicella pneumonia – secondary bacterial pneumonia S aureus & pneumococci – post-infectious encephalitis – generalized varicella (in immunocompromised patients) – congenital and neonatal varicella 4/13/2012 Dr.T.V.Rao MD 13
  14. 14. Chicken pox.4/13/2012 Dr.T.V.Rao MD 14
  15. 15. Skin lesions of chickenpox4/13/2012 Dr.T.V.Rao MD 15
  16. 16. Skin lesions showing different stages4/13/2012 Dr.T.V.Rao MD 16
  17. 17. Chicken pox4/13/2012 Dr.T.V.Rao MD 17
  18. 18. Pathogenesis and Pathology• Varicella virus enter through URT/Conjunctiva. Lymph nodes Viremia Liver and spleenSecondary viremiaInfects Mononuclear CellsRash Vesicle formation 4/13/2012 Dr.T.V.Rao MD 18
  19. 19. Herpes Zoster• Skin Lesions• Inflammation of Sensory Nerves and Ganglia• Single Ganglion• Dorsal root Ganglion4/13/2012 Dr.T.V.Rao MD 19
  20. 20. Herpes Zoster involving a Nerve segment4/13/2012 Dr.T.V.Rao MD 20
  21. 21. Complications• Bacterial Infections• Viral Pneumonia• Bleeding Problems• Infection of the brain4/13/2012 Dr.T.V.Rao MD 21
  22. 22. Other Complications.• Encephalitis,• Mother to Child transmission• Varicella Pneumonia.• Fatal Complications.4/13/2012 Dr.T.V.Rao MD 22
  23. 23. Herpes Zoster in Immune compromised• HIV / AIDS• Malignancies.• Organ transplantations• Corticosteroid usage• Leukaemias.4/13/2012 Dr.T.V.Rao MD 23
  24. 24. Pain and hyperesthesia4/13/2012 Dr.T.V.Rao MD 24
  25. 25. Laboratory Diagnosis. Smears --Scrapings from Lesions Demonstration of Multi nucleated giant cells Tzanck smearsDNA DemonstrationCell cultures,Fluorescent –antibodyELISA PCR4/13/2012 Dr.T.V.Rao MD 25
  26. 26. Epidemiology• Communicable Disease• World wide prevalence• Common in < 10 year olds.• Zoster in Adults Droplet spread4/13/2012 Dr.T.V.Rao MD 26
  27. 27. Treatment• Specific treatment is indicated mainly in Immunodeficient and elderly subjects and also in complicated with Varicella pneumonia,encephalitis,and disseminated zoster• Acyclovir and Famiciclovir.4/13/2012 Dr.T.V.Rao MD 27
  28. 28. Prevention of Chickenpox Do nothing Susceptible population Immunize children live attenuatedadults living in close proximity vaccine Protect if contact with patient with chickenpox and at risk of severe disease 4/13/2012 Zoster Immune Globulin (ZIG) Dr.T.V.Rao MD 28
  29. 29. Vaccines available • A live modified Varicella virus lyophilised vaccine which can be stored at low temp is available for protection • Children 1 -12 years given single dose. • >12 years 2 doses 2 -6 weeks apart • High titre serum from convalescing from herpes zoster protect Immunocompromised children. • But not useful for treatment4/13/2012 Dr.T.V.Rao MD 29
  30. 30. Varicella Vaccines• Two live attenuated varicella virus vaccines licensed for use in US: Varivax® and Proquad®• Both vaccines may be used for first and second doses of varicella vaccine• Varivax ® (1,400 pfu) is the single-antigen varicella vaccine licensed in 1995 for use among healthy persons aged ≥ 12 months• Proquad® or MMRV (9,800 pfu) is a combination measles, mumps, rubella, and varicella vaccine licensed in 2005 for use among healthy children aged 12 months-12 yearsCDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) MD 4/13/2012 Dr.T.V.Rao 30
  31. 31. Current Varicella Vaccination Policy in the United States Implemented routine 2-dose childhood varicella vaccination program in 2006 – 1st dose at age 12-15 months – 2nd dose at age 4-6 years – Catch-up vaccination of children and adolescents who had previously received one dose – 2 doses for all adolescents and adults without evidence of immunity – Pre-natal screening and post-partum vaccinationCDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) MD 4/13/2012 Dr.T.V.Rao 31
  32. 32. To vaccinate or not ? Positive Side• Saves lives• Saves Money, Time• Children and Students don’t miss school• 85% percent affective in preventing disease• Less likely to develop Shingles• If someone does get Chicken Pox after vaccination, it usually is a lot less worse than a typical case resulting in a few skin lesions, little to no fever and lasting fewer days4/13/2012 Dr.T.V.Rao MD 32
  33. 33. Contra-indications and Precautions for Varicella Vaccination • Severe allergic reaction to vaccine component or following a prior dose • Immunosuppression • Pregnancy • Moderate or severe acute illness • Recent blood product (due to potential inhibition of response to varicella vaccination)CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) MD 4/13/2012 Dr.T.V.Rao 33
  34. 34. Varicella Vaccination in Certain Groups of Immunocompromised Persons• Varicella vaccine may be administered to persons with isolated Humoral immunodeficiency• Patients with leukemia, lymphoma, or other malignancies whose disease is in remission and those chemotherapy have been terminated ≥ 3 months can receive live-virus vaccines• Consider varicella vaccination for HIV-infected children with CD4+ T-lymphocyte percentage of 15% or higher – Eligible children should receive 2 doses of single- antigen varicella vaccine 3 months apartCDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) MD 4/13/2012 Dr.T.V.Rao 34
  35. 35. HIV and Varicella Vaccine• Data on use of varicella vaccine in HIV-infected adolescents and adults lacking, but safety is likely to be similar to response in HIV-infected children. Vaccination may be considered for HIV-infected persons with CD4+T-lymphocyte count ≥ 200 cells/ml4/13/2012 Dr.T.V.Rao MD 35
  36. 36. Post-exposure Prophylaxis• Varicella vaccine recommended for use in healthy persons without evidence of immunity within 3-5 days after exposure to varicella – ≥ 90% effective in preventing varicella if vaccinated within 3 days of exposure and ~ 70% effective in preventing varicella and ~100% effective in modifying severe disease if given within 5 days – Vaccination still recommended for those with no other evidence of immunity even after 5 days of exposure because Dr.T.V.Rao help provide protection it will 4/13/2012 of Varicella. MMWR 2007; 56(No. RR-4) MD 36CDC. Prevention against future exposures
  37. 37. Varicella Vaccine Adverse Events• Non-serious adverse events • Rash, Fever Injection site reactions • Possible vaccine failure• Serious adverse events are rare • Encephalitis Ataxia • Pneumonia Arthritis • Hepatitis Vasculitis • Thrombocytopenia4/13/2012 Dr.T.V.Rao MD 37 Chaves J Infect Dis 2008
  38. 38. Use of Hyper immune Globulins in Varicella Infection• Varicella Zoster Immune Globulin (available product, VariZIG™) recommended for certain groups at high risk for severe disease within 96 hours after exposure4/13/2012 Dr.T.V.Rao MD 38
  39. 39. To Vaccinate or Not ? Other Side• Vaccine is new. Don’t know about long term side affects yet• Chicken Pox is usually pretty harmless. No use in vaccinating• The vaccine is only expected to be effective for 20 years. Those who were vaccinated will need a booster shot. Between the time the original shot wears off and the booster shot, those who were vaccinated can now develop Chicken Pox later in life when its more dangerous4/13/2012 Dr.T.V.Rao MD 39
  40. 40. People who should not be vaccinated• If you had a serious allergic reaction to Chicken Pox vaccine• You have a moderate to serious illness• You’re pregnant• Unable to fight off serious infection• People that have been vaccinated for Chicken Pox can still get Shingles, but they are less likely than someone that hasn’t been vaccinated to get it4/13/2012 Dr.T.V.Rao MD 40
  41. 41. • Programme Created by Dr.T.V.Rao MD for Medical and Health Care Workers • Email • doctortvrao@gmail.com4/13/2012 Dr.T.V.Rao MD 41

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