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DNA Viruses
HHAPPPPy viruses
- Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma
- All except Parvoviridae are dsDNA
- ALL linear except papilloma, polyoma and hepadnaviruses (circular)
- Pox complex envelope; and replicates in cytoplasm therefore carries its own DNA-dependent RNA polymerase
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Herpes Viridae
- enveloped
- replicates in nucleus
- get packed in the nucleus as well- intranuclear inclusion bodies
- some of it buds off the cell membrane
- remaining forms fusion w/ other cells and moves from one cell to next...syncytia fomation = multinucleated cells
- Tzanck smear show giant multinucleated cells
- primary infection
reside in a nerve. Reactivation occurs during stress, menstruation, anxiety, fever etc. vesicles looks like dew on a rose petal
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HSV-1 and HSV-2
- establish infection in the mucosal epithelial cells and leads to formation of vesicles.
- HSV-1 occur above the waist and HSV-2 occur below
- Gingivostomatitis and cold sores: blister-like lesions on the oral mucosa and latent in trigeminal ganglion
- Keratoconjunctivitis: spread from lips to eyes by rubbing.
- Meningoencephalitis: #1 cause. spread from trigeminal ganglion. fever, headache and confusion; presence of erythrocytes and lymphocytes in the CSF. focal temporal lesions and perivascular cuffing.
- Neonatal Herpes: passage through infected birth canal. Disseminated w/ liver involvement and high mortality, Encephalitis (HSV-2)- high mortality, skin, eyes or mouth
- Rx: Acyclovir
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Varicella Zoster virus (VZV)
- airborne, respiratory droplets
- enters the respiratory tract --> replicates in LN --> spleen and liver --> skin rash --> latent in the dorsal root ganglion
- Chicken Pox: fever, pharyngitis, malaise, rhinitis. Rash in different stages.
- Shingles: Zoster, pain and vesicles located to 1 dermatome unilaterely.
- can cause pneumonia and encephalitis
- Aspirin contraindicated due to association w/ Reye's syndrome
- Live, attenuated vaccine
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Epstein-Barr Virus (EBV)
- Virus infects nasopharyngeal epithelial cells, salivary and lymphoid tissues (posterior cervical nodes) --> latent infection of B cells (binds to CD 21) --> immune response which consists mainly of Tcells, results in the production of atypical reactive T cells (downey cells) and large LN
 - EBV acts as B-Cell mitogen; therefore, heterophile antibodies are produces
- heterophile-positive mononucleosis, kissing disease: fatigue, fever, sore throat, lymphadenopthy and splenomegaly. Heterophile antibodies detected by agglutination of sheep or horse RBCs.
- Hairy Oral leukoplakia: hyperproliferation of lingual epithelial cells. occurs in AIDS patients
- Burkitt Lymphoma: cancer of maxilla, mandible (children) and abdomen (adult)
- Hodgkin Lymphoma
- Nasophargeal carcinoma
in Asian
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Cytomegalovirus (CMV)
- infects the salivary gland epithelial cells and establishes a persistent infection in fibroblasts, epithelial cells and macrophages
- Latency in mononuclear cells, owl-eye inclusion
- Cytomegalic inclusion disease: #1 in utero infection characterized by jaundice, hepatosplenomegaly, thrombocytic purpura ("blueberry Muffin baby"), pneumonitis, CNS damage to death
- mononucleosis: #1 cause of heterophile-negative mononucleosis
- intestitial pneumonitis to severe systemic infection in transplanted and AIDS patient
- CMV retinitis in AIDS patient
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HHV-6
- Respiratory droplets
- Roseola: high fever for 3-5 days (can cause seizures) followed by nonfever lacy body (diffuse macular) rash
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HHV-8
- sexually
- turns on VEGF, which plays a direct role in development of Kaposi's sarcoma in HIV patients
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Parvovirus
B19
- Naked, single stranded
- flu-like symptoms
- aplastic crises in sickle cell disease
- slapped cheeks rash in children- type III hypersensivity
- Erythema infectiosum (fifth disease)
- RBC destruction in fetus leads to hydrops fetalis and death
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Papillomaviridae
- naked
- DS circular
- E6 and E7 inhibit tumor suppressor genes p53 and Rb
- cutaneous warts commonly found in hands, fingers and sole of foot
- anogenital warts are serotypes 6, 11, 16, 18, 31, 35
- positive pap smear has large nucleus w/ vacuoles surrounding the nucleus =koilocytic cells
- Gardasil
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Polyomavirus
- naked
- ds circular
- causes infection in immunosuppressed
- BK: reneal disease in AIDS patients
- JC: Progressive multifocal leukoencephalopathy (PML) in AIDS and transplant patients
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Adenoviridae
- naked, penton fibers act as hemagglutinin- toxic to cells
- Acute respiratory disease and pneumonia: spring and winter
- pharyngoconjunctivitis: swimming pool conjunctivitis, pink eye (watery discharge; bacteria discharge is purulent), fever, sore throat
- Epidemic Keratoconjunctivitis: foreign particles in eye
- Acute hemorrhagic cystitis: dysuria, hematuria child doesn't appear sick...acute post-strep glomerlonephritis-child appears sick
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Poxviridae
- replicate in cytoplasm
- complex enveloped
- Largest of the virus
- Potential warfare
- Smallpox: variola: respiratory
- eradicated
- respiratory --> LN -->flu-like illness --> rash cover entire body w/in 24 hrs (all vesicles same stage)
- Diagnosis: guarnieri bodies in infected cells
- Molluscum contagiosum: direct contact (sexual)
- flesh-colored dome lesions w/ central dimple
- Vaccinia: cowpox ("milkmaid's blisters"
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Hepadnavirus
- Enveloped
- circular DS
- causes acute and chronic hepatitis
- vaccine available contains HBV surface antigen
- not a retrovirus but has reverse transcriptase
- Presence of HBsAg could mean acute or chronic
- - chronic if presented more than 6 months
- Presence of HBsAg + HBeAg + IgG HBcAb means acute on chronic
- Presence of HBsAg + HBeAg + IgM HBcAb means acute
- Preasence of Anti-HBsAb + anti-HBeAb + IgG HBcAb means recovery
- Anti-HBsAb means immunized
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