1 / 76

HERPES VIRUSES

HERPES VIRUSES. Herpes means that some of the lesions are creeping in nature Infect both warm and cold blooded animals Infections include - trivial mucocutaneous infection - life threatening cancers Have become successful pathogens due to latency and reactivation.

camden-leblanc
Télécharger la présentation

HERPES VIRUSES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HERPES VIRUSES

  2. Herpes means that some of the lesions are creeping in nature • Infect both warm and cold blooded animals • Infections include - trivial mucocutaneous infection - life threatening cancers • Have become successful pathogens due to latency and reactivation

  3. CLASSIFICATION(Human pathogens) • DNA VIRUSES • Icosahedral • Large baggy envelope • DNA polymerase • HSV and VZV code for thymidine kinase - activate certain antiviral drugs (SUIZIDING) • Replication in nucleus of host cell

  4. Herpes viruses have a similar morphology • Share common antigens • Can differentiate by their genome and by serological tests

  5. CLASSIFICATION(Human pathogens) • Alphaherpesvirinae • Herpes simplex virus type 1 HSV-1 • Herpes simplex virus type 2 HSV-2 • Varicella-zoster virus VZV • Betaherpesvirinae • cytomegalovirus CMV • Human herpesvirus type 6 HHV-6 • Human herpesvirus type 7 HHV-7 • Gammaherpesvirinae • Epstein-Barr virus EBV

  6. HERPES SIMPLEX VIRUS (HSV) • HSV 1 infect the upper part of the body - mouth and the face • HSV 2 infect the lower part of the body - genital infections • There is little cross protection • Therefore, you can get both the infections

  7. Primary infection -first contact with HSV • Latent infection -persistent virus in root ganglia • Reactivation -production of infective virus by latently infected cell • Recurence -clinically apparent disease produced by reactivation

  8. Man is the only natural host • Primary infection occurs - skin - Oral mucous membrane - eyes

  9. Pathogenesis Entry by skin or mucous membranes viral multiplication sensory nerve lysis of cells root ganglia vesicles latency ulcers COLD FEVER SURGERY UNKNOWN REACTIVATION

  10. Sources of infection - Saliva - Skin lesions - Oropharyngeal lesions - Carriers

  11. Viral DNA may get integrated in to the host genome or virus may just remain in the ganglia • Primary infection usually due to type 1 happens at 6 months to 3 yrs of age • Only 10-15% of children show acute gingivostomatitis OTHERS ARE ASYMTOMATIC

  12. About 75% of the adults show +ve for HSV 1 infection • HSV 1 infections include -i. Oropharyngeal . Children - very painful . due to kissing of elders . acute gingivostomatitis . problem of feeding

  13. ii. Dermal - mainly among the health care workers - Herpetic whitlow - painful - heals without treatment - no pus/is it necessary to do a stain - Herpes gladiatorum - among wrestlers - eczema herpeticum

  14. ECZEMA HERPETICUM

  15. Iii. Ophthalmic - Keratoconjunctivitis with dendritic ulcers - Repeated attacks can lead to blindness 1V. Meningitis and encephalitis HSV 2 infections include Genital - male and female

  16. Male - metaus with dysuria (you may not see ?) - hepatic proctitis Females - infection of the labia/vulva/perineus - cervicitis Neonatal infections At what stage ?

  17. During the delivery What are the other infections acquired by this mode

  18. Candida can super infect, So what ?

  19. Immune response There will be IgM and IgG BUT NOT PROTECTIVE

  20. High antibody titres do not prevent latent infections • Latent infections - recurrent herpes labialis - acute keratoconjunctivitis • Recurrent lesions may lead to - dendritic ulcers - corneal ulcers

  21. Laboratory diagnosis • Childhood infections common • Second peak at onset of sexual activity • Viral shedding • persons with recurrences • infected but asymptomatic persons • Mucocutaneous lesions can be diagnosed clinically

  22. Useful • genital & eye infections • HVZ & HSV in immunocompromised patients • herpes encephalitis • Specimens • aspirate from vesicle • scraping from base of ulcer • serum / CSF for antibody

  23. EM detection • Cell culture • Stained smears - for multinucleated giant cells with intranuclear inclusions

  24. Treatment • Treatment • Acyclovir • Idoxyuridine

  25. 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 • seconday bacterial pneumonia S aureus & pneumococci • post-infetious encephalitis • generalised varicella (in immunocompromised patients) • congenital and neonatal varicella

  26. HERPES ZOSTER • Reactivation of HVZ • dermatomal distribution • may recur • can disseminate in immunocompromised patients • complications • post herpetic pain • ophthalmic zoster -corneal scarring and loss of vision DIAGNOSIS CLINICAL EM of vesicle fluid SEROLOGY IgM detection

  27. People can bet varicella from zoster • Therefore, having immunocompromised patients in the hospital is a problem • These patients should be looked after by the staff who are immune to chickenpox

  28. Pain and hyperaesthesia

  29. Pain and hyperaesthesia

  30. Pain and hyperaesthesia

  31. Pain and hyperaesthesia

  32. Prevention of Chickenpox Do nothing Susceptible population children adults living in close proximity Immunize live attenuated vaccine Protect if contact with patient with chickenpox and at risk of severe disease Zoster Immune Globulin (ZIG)

  33. Treatment • Acyclovir 10mg/Kg x 5 times/day • Famcyclovir NO RELIABLE DATA ON ROLE OF ACYCLOVIR IN PREVENTION OF CHICKENPOX

More Related