DNA VIRUSES Flashcards
Infection is associated with Burkitt lymphoma and nasopharyngeal carcinoma
Epstein-Barr virus
-Burkitt lymphoma is more commonly associated with EBV in AFRICA; Nasopharyngeal carcinoma is more common in pts from ASIA
A major cause of hepatocellular carcinoma worldwide
Hepatitis B virus
-Although less likely to progress to either CIRRHOSIS or CARCINOMA than is HCV, the worldwide prevalence, especially in AFRICA, makes HBV the leading cause
Major cause of sexually transmitted and vertically transmitted hepatitis
Hepatitis B virus
-Histologically, infected cell appear as GROUND GLASS HEPATOCYTES b/c of presence of EXCESS SURFACE ANTIGEN within the cytoplasm
Infection causes cauliflower-like lesions on the external genitals or perianal areas
Human Papilloma virus (HPV)
-CONDYLOMA ACUMINATUM is microscopically characterized by the presence of vacuolated infected cells, termed KOILOCYTES
Infection is linked to premalignant lesions on the vulva, cervix, penis, and anus
Human papilloma virus (HPV)
-viral oncoprotein E6 binds to p53 and viral oncoprotein E7 binds to Rb, stimulating infected cells to undergo uncontrolled growth
Infection of keratinized tissue results in the formation of warts on the hands and feet
Human papilloma virus (HPV)
-typically caused by infection with HPV 1-4, with the development of warts on the hands [Verruca Palmaris] and feet [Verruca plantaris]
Causes chickenpox upon initial infection, and shingles upon reactivation
Varicella-Zoster virus (VZV)
-The only herpes virus with a LIVE ATTENUATED VACCINE; reactivation most commonly occurs along the dermatomal distribution of the OPHTHALMIC DIVISION OF TRIGEMINAL N.
Infection results in the production of heterophil antibodies
Epstein Barr virus (EBV)
-viral infx results in the POLYCLONAL ACTIVATION OF B CELLS with the production of ANTIBODIES TO SHEEP RBCs [HETEROPHIL ANTIBODIES] that can be detected with the MONOSPOT TEST
Infection results in Cowdry Type A intranuclear inclusions and multinucleated giant cells
Herpes Simplex Virus-1 (HSV-1)
-1 OF THE MOST COMMON HUMAN VIRAL INFECTIONS, the virus enters BROKEN SKIN and remains latent in the TRIGEMINA GANGLION, with spontaneous reactivation triggered by axonal injury, STRESS, or UV LIGHT
Infection causes Roseola infantum or Sixth disease
Herpes Virus 6
-Common, mild, childhood disease characterized by HIGH FEVER AND A SKIN RASH
Causes aplastic crisis in pts with sickle cell anemia, thalassemias, and acquired hemolytic anemias
Parvovirus B19
-virion replicates best in rapidly dividing ERYTHROBLASTS, resulting in cell lysis
Found as a contaminant in preparations of polio vaccines produced in monkey cell culture
SV40
-this POLYOMA VIRUS is typically a SIMIAN VIRUS, which can CAUSE TUMORS IN MICE, although no pathogenic effects have been reported in humans
Infection results in the successive appearance of macules, papules, vesicles, and crusts all seen simultaneously
Varicella-zoster virus (VZV)
-severe infection can result in PNEUMONIA WITH MULTINUCLEATED GIANT CELLS
Most common viral cause of congenital abnormalities in the USA
Cytomegalovirus (CMV)
-infected cells display characteristic “OWL EYE” intranuclear viral inclusions
Major cause of epidemic conjunctivitis (Pink eye)
Adenovirus
-Various subtypes are also associated with PHARYNGITIS and GASTROENTERITIS
DNA virus that encodes an RNA-dependent DNA polymerase (reverse transcriptase)
Hepatitis B virus (HBV)
-the virus produces its DNA genome through a SINGLE mRNA TRANSCRIPT, requiring the presence of a reverse transcriptase
Appearance in the serum as Dane particles and as large amounts of filaments of excess surface antigen
Hepatitis B virus (HBV)
-the SURFACE ANTIGEN [HBsAg] is now produced by RECOMBINANT DNA TECHNOLOGY and is given as a VACCINE
Leading cause of sporadic encephalitis in the USA
Herpes Simplex Virus-1 (HSV-1)
-Commonly affects the TEMPORAL LOBE
Reactivation of latent viral infection in immunocompromised pts can result in Progressive Multifocal Leukoencephalopathy (PML)
JC virus
-this POLYOMAVIRUS causes FOCI OF DEMYELINATION surrounded by oligodendrocytes with viral inclusions
The only DNA virus that replicates solely in the cytoplasm and that carries its own DNA-dependent polymerases
Poxvirus
-the LARGEST OF ALL VIRUSES, it appears BRICK-SHAPED by electron microscopy, and causes characteristic GUARNIERI INCLUSION BODIES when replicating in cells
Associated with Reye syndrome when the accompanying fever is treated with aspirin
Varicella-zoster virus (VZV)
-Reye syndrome is an ACUTE ENCEPHALOPATHY associated with FATTY INFILTRATION of the LIVER, which is often FATAL
Infection of a child results in a “slapped cheek” appearance
Parvovirus B19
-this SINGLE-STRANDED DNA virus causes ERYTHEMA INFECTIOSUM or FIFTH DISEASE
This contagious virus causes benign epithelial tumors that appear as pearly, umbilicated nodules with a central caseous plug
Molluscum contagiosum
-these lesions caused by this POXVIRUS occur as CLUSTERS on the trunk, genitalia, and extremities; it is transmitted by towels, barbers, swimming pools, and sexual activity
Most common cause of vesiculo-ulcerative lesions on the penis or vagina
Herpes simplex virus-2 (HSV-2)
-REACTIVATION of the virus is common, because the virus remains LATENT in the LUMBAR AND SACRAL GANGLIA; detected using the Tzanck test
Causes cranberry-pigmented lesions on AIDS patients
Herpes virus 8
-KAPOSI SARCOMA is a TUMOR OF BLOOD VESSELS characterized by a DISARRAY OF VASCULAR channels filled with RBCs
Infection with this virus is a leading cause of corneal blindness in the USA
Herpes simplex virus-1 (HSV-1)
-KERATOCONJUNCTIVITIS results in DENDRITIC ULCERS that can be visualized with FLUORESCEIN STAINING
Major cause of retinitis, leading to blindness, in an immunocompromised patient
Cytomegalovirus (CMV)
-can also cause life-threatening INTERSTITIAL PNEUMONIA in such patients and HETEROPHIL-NEGATIVE INFECTIOUS MONONUCLEOSIS in immunocompetent individuals
Major cause of infectious mononucleosis (kissing disease)
Epstein-Barr virus
-characterized by weeks of fever, malaise, and LAD, the peripheral blood contains an abundance of atypical lymphs, which are T cells that recognize EBV-infected cells
