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  1. Herpesvirus
    • Large, enveloped, dsDNA virus
    • Icosahedral capsid containing 162 capsomeres
    • Linear dsDNA genomes that can vary in size
    • Grouped into three subfamilies based on viral characteristics
  2. Human Herpes Simplex Stucture
    • Two distinct epidemiologic and antigenic types, HSV-1 and HSV-2
    • 50% sequence homology between the two
    • Linear dsDNA genome
    • Capsid surrounds DNA core and over capsid is tegument (protein filled region
    • Envelope contains glycoproteins
  3. HSV disease syndrome
    • HSV-1 and HSV-2 often infect the same tissue
    • Acute and latent infections
    • Cause painful but benign lesions – clear vesicle on an erythematous base
  4. HSV-1
    clinical disease
    • Gingivostomatitis
    • Labialis (cold sores)
    • Keratoconjunctivitis
    • Encephalitis
    • Mild or fulminant
    • Herpatic whilow
  5. HSV-1
    clinical disease
    Gingivostomatitis
    • —Most common in children 1-6 years, fever, oral blisters on buccal mucosa, tongue, and gums
    • —Vesicles which ulcerate 7-10 days in duration
  6. HSV-1
    clinical disease
    Labialis (cold sores)
    • Vesicles at mucocutaneous junction of lips
    • Recurrent (latent)
  7. HSV-1
    clinical disease
    Keratoconjunctivitis
    • —Corneal ulceration, usually limited to one eye
    • —Recurrent, leading to permanent scarring and blindness
  8. HSV-1
    clinical disease
    Encephalitis
    Limited to temporal lobe, high mortality
  9. HSV-1
    clinical disease
    Herpatic whilow
    • Tips of fingers and nails
    • —Occurs in nurses/physicians who attend patients with HSV infection, thumbsucking children, people who have genital HSV
  10. HSV-1
    clinical disease
    Mild or fulminant
    • Mild or fulminant
    • Acquired by children with active eczema
  11. HSV-2
    • Usually causes genital herpes (10% cause by HSV-1)
    • 80% of patients develop recurrent infections within 12 months
  12. HSV-2
    Clinical disease
    • Vulvoganitis
    • Progenitalis
    • Aseptic meningitis
    • Neonatal herpes
  13. HSV-2
    Vulvoganitis
    • Mucous membranes of skin of labia, lower vagina, cervix
    • Lesions become ulcerated, painful
  14. HSV-2
    Progenitalis
    Ulcers on penis and/or skin in groin or perianal area
  15. HSV-2
    Neonatal herpes
    • Contracted during delivery
    • —Widespread organ involvement
    • High mortality – more than 60%
  16. HSV latency
    • All herpes viruses establish latent infections
    • Site of latency and feature of reactivation disease is different for each virus
    • HSV Reactivation – same site as primary infection
    • DNA resides in ganglia (trigeminal root ganglion, sacral root ganglion)
    • Reactivation: trauma, fever, sunlight, excitement, emotional stress
  17. HSV Diagnosis
    • Isolation of virus – definitive assay
    • —Stain biopsy material (immunofluorescence)
    • —DNA detection by PCR in tissue sample (latent infection)
  18. HSV Treatment
    • Acyclovir and closely related drugs (Valtrex)
    • —Eye infections (topical) – trifluridine, penciclovir, acylcovir
  19. Varicella-Zoster Virus (VZV)
    • ¢Human Herpesvirus 3
    • Clinical chicken pox (primary infection)
    • Virus entry through inhalation
    • Replicates in respiratory tract and invades lymph nodes
    • Viremia: spreads to liver spleen, reticuloendothelial system
    • Secondary viremia : spreads to the skin
    • Latency in neurons
  20. Chicken pox
    • Maculopapular rash appears first on head, neck and trunk
    • Vesicles contain clear fluid (itch)
    • Vesicle will become pustular and begin to crust
    • Recovery in about 2 weeks
    • Adult infection more severe: 20-30% develop pneumonia
    • Neonatal infections – encephalitis
    • Immunosuppressed – severe progressive infection
  21. VZV - Shingles
    • Shingles: reactivation of varicella-zoster
    • DNA remains latent in ganglia
    • Occurrence increases with age (50% over 50 yrs)
    • Onset of pain occurs before appearance of vesicles
    • Usually unilateral
  22. VZV - Shingles
    Treatment
    • Supportive
    • —Acyclovir for extreme cases
  23. VZV - Shingles
    Diagnosis
    • Clinical picture
    • —Immunofluorescent antibody staining
  24. VZV - Shingles
    Prevention
    • Vaccine:
    • Varivax – live attenuated vaccine, administered between 12-18 months of age
    • Zostavax –stronger formulation of Varivax, recommended to adults 60 or older
    • —50% reduction in shingles occurrence
  25. Epstein-Barr Virus (EBV)
    • Human herpesvirus 4
    • Etiologic agent of infectious mononucleosis (mono) and Burkitt’s Lymphoma
    • Linked with Hodgkins lymphoma
    • Infects B cells and epithelial cells



  26. EBV
    Diagnosis

    ¢Infects B
    cells and epithelial cells
    • Clinical presentaion
    • Complete blood cell count – atypical lymphocytes
    • Heterophile – positive antibodies
    • —Hetrophile antibodies (sheep erythocyte agglutinins; used as monospot test)
    • —Activation of B cells by EBV produces a wide range of antibodies
    • —Positive in 50% on presentation and 90% at some point
    • Serology: expensive, but can be useful
    • —Demonstrate antibody to viral capsid antigen (VCA) which rises quickly and persists for life
    • —Antibodies to EB nuclear antigens (EBNA) rise later and decreases in about 1 month
    • —A high titer of VCA and titer of EBNA suggest recent infection
  27. EBV – Burkitt’s lymphoma
    Epidemiology
    • —Central and East Africa - tumor in jaw area
    • —China and Southeast Asia – nasopharyngeal carcinoma
  28. EBV – Burkitt’s lymphoma
    Treatment and Prevention
    • Supportive
    • Acyclovir can suppress the replication
    • —No vaccine
  29. EBV – Hairy oral leukoplakia
    • Unusual manifestation of a productive EBV infection of epithelial cells
    • Characterized by lesions of the tongue and mouth
    • Opportunistic manifestation of AIDS patients
  30. Cytomegalovirus
    (CMV)
    • HHV-5
    • Largest genome of herpes virus (~240 kb)
    • Similar to HSV but highly regulated – slow replication and slow disease effects
    • Nuclear and cytoplasmic inclusion bodies, induction of giant cell
  31. CMV
    Clinical Disease
    Transmission
    • Close contact, sexually transmitted, virus can be recovered from all body fluids:
    • saliva, urine, semen, and cervical secretions
  32. CMV
    Clinical Disease
    • High infection rates in early childhood and early adulthood
    • —Usually asymptomatic
    • —Heterophil negative mononucleosis
    • —Systemic CMV infection, pneumonia and hepatitis in immunosuppressed patients (transplant)
    • —In AIDS patients: diarrhea, retinitis
  33. CMV
    clinical disease
    Congential
    • Most infants appear normal at birth
    • May develop hearing loss or some mental retardation often later
    • Infants with sympotmatic illness at birth demonstrate hepatosplenomegaly, jaundice, anemia, rash
    • Neonatal– usually asymptomatic
    • Immunosuppressed –pneumonia, hepatitis
  34. CMV Diagnosis
    • —Culture in diploid fibroblast, serology, PCR
    • —Hallmark is cytomegalic cell (large cell with basophilic nuclear inclusion body – “owls eye”)
  35. CMV Treatment
    Ganciclovir, valganciclovir
  36. Human Herpes 6
    • Genetically distinct but morpholically similar to other herpes virus
    • Replicates in lymphoid tissue – preferentially in T lymphocytes
    • Cytopathic for T lymphocytes in cell culture
    • Serologic studies indicate that almost all children are infected by age 5.
    • Most communicable of all herpes virus
    • Spread by close personal contact or by respiratory route
  37. Human Herpes 6
    Treatment
    Acyclovir
  38. HHV-7
    • Closely related to HHV-6
    • Causes exanthem subitum (roseola) – one of the five classical childhood exanthems
    • Recover without complications
  39. HHV-8
    • STD
    • Kaposi’s sarcoma-associated herpesvirus, KSHV
    • Isolated in culture and closely related to EBV
    • Infects B lymphocytes
    • Immunosuppression, genetic predisposition are cofactors
    • Interferon-alpha can be effective as treatment
  40. HHV-8
    Treatment
    Interferon-alpha can be effective
  41. Pharyngitis
    Streptococcus pyogenes
  42. Sinusitis
    • Streptococcus pneumoniae
    • Haemophilus influenzae
    • Moraxella catarrhalis
  43. Otitis externa
    • Pseudomonas aeruginosa
    • Staphylococcus aureus
  44. Otitis media (inner/middle)
    • Streptococcus pneumoniae
    • Haemophilus influenzae
    • Moraxella catarrhalis
  45. Conjunctivitis
    • Staphylococcus aureus
    • Streptococcus pneumoniae
    • Haemophilus aegyptius
  46. Keratitis
    • Staphylococcus aureus
    • Streptococcus pneumoniae
    • Pseudomonas aeruginosa
  47. Bronchitis
    • Haemophilus influenzae
    • Streptococcus pneumoniae
  48. Empyema (pus in body cavity)
    • Staphylococcus aureus
    • Streptococcus pneumoniae, group A
  49. Pneumonia
    • Streptococcus pneumoniae
    • Staphylococcus aureus
    • Klebsiella pneumoniae
    • other Enterobacteriaceae
    • Mycoplasma pneumoniae
    • Legionella species
  50. Cystitis and Pyelonephritis
    • Escherichia coli
    • Proteus mirabilis
    • other
    • Enterobacteriaceae
  51. Renal abscess
    Staphylococcus aureus
  52. Prostatitis
    Escherichia coli
  53. Endocarditis
    Viridans Streptococcus

    coagulase-negative Staphylococcus
  54. Myocarditis
    • Corynebacterium diphtheriae
    • Clostridium perfringens
  55. Pericarditis
    • Streptococcus pneumoniae
    • Staphylococcus aureus
  56. Sepsis
    • Staphylococcus aureus
    • coagulase-negative Staphylococcus
    • Escherichia coli
  57. Meningitis
    • Group B Streptococcus
    • Streptococcus pneumoniae
    • Neisseria meningitidis
  58. Encephalitis
    • Listeria monocytogenes
    • Treponema pallidum
  59. Impetigo
    • Group A Streptococcus
    • Staphylococcus aureus
  60. Folliculitis
    • Staphylococcus aureus
    • Pseudomonas aeruginosa
  61. Furuncles/Carbuncles
    • Staphylococcus aureus
  62. Cellulitis
    • Group A Streptococcus
    • Staphylococcus aureus
  63. Necrotizing cellulitis and fasciitis
    • Group A Streptococcus
    • Clostridium perfringens
  64. Burn infection
    Pseudomonas aeruginosa
  65. Skin Infection
    Surgical wounds
    Staphylococcus aureus
  66. Gastritis
    • Helicobacter pylori
  67. Gastroenteritis
    • Salmonella species
    • Shigella species
    • Campylobacter jejuni
  68. Food Intoxication
    • Staphylococcus aureus
    • Bacillus cereus
  69. Osteomyelitis
    • Staphylococcus aureus
    • Salmonella species
  70. Arthritis
    • Staphylococcus aureus
    • Neisseria gonorrhoeae
  71. Genital Ulcers
    • Treponema pallidum
    • Haemophilus ducreyi
  72. Urethritis
    • Neisseria gonorrhoeae
    • Chlamydia trachomatis
  73. Vaginitis
    • Mycoplasma hominis
    • Mobiluncus species
    • Gardnerella vaginalis
  74. Cervicitis
    • Neisseria gonorrhoeae
    • Chlamydia trachomatis
  75. Granulomatous Infections
    • Mycobacterium tuberculosis and
    • other species
    • Nocardia species
    • Treponema pallidum
Author
shsugal
ID
25514
Card Set
MM
Description
Medical Micro Final
Updated

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