DNA VIRUSES

Question 1

Infection is associated with Burkitt lymphoma and nasopharyngeal carcinoma

Answer 1

Epstein-Barr virus

-Burkitt lymphoma is more commonly associated with EBV in AFRICA; Nasopharyngeal carcinoma is more common in pts from ASIA

Question 2

A major cause of hepatocellular carcinoma worldwide

Answer 2

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

Question 3

Major cause of sexually transmitted and vertically transmitted hepatitis

Answer 3

Hepatitis B virus

-Histologically, infected cell appear as GROUND GLASS HEPATOCYTES b/c of presence of EXCESS SURFACE ANTIGEN within the cytoplasm

Question 4

Infection causes cauliflower-like lesions on the external genitals or perianal areas

Answer 4

Human Papilloma virus (HPV)

-CONDYLOMA ACUMINATUM is microscopically characterized by the presence of vacuolated infected cells, termed KOILOCYTES

Question 5

Infection is linked to premalignant lesions on the vulva, cervix, penis, and anus

Answer 5

Human papilloma virus (HPV)

-viral oncoprotein E6 binds to p53 and viral oncoprotein E7 binds to Rb, stimulating infected cells to undergo uncontrolled growth

Question 6

Infection of keratinized tissue results in the formation of warts on the hands and feet

Answer 6

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]

Question 7

Causes chickenpox upon initial infection, and shingles upon reactivation

Answer 7

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.

Question 8

Infection results in the production of heterophil antibodies

Answer 8

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

Question 9

Infection results in Cowdry Type A intranuclear inclusions and multinucleated giant cells

Answer 9

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

Question 10

Infection causes Roseola infantum or Sixth disease

Answer 10

Herpes Virus 6

-Common, mild, childhood disease characterized by HIGH FEVER AND A SKIN RASH

Question 11

Causes aplastic crisis in pts with sickle cell anemia, thalassemias, and acquired hemolytic anemias

Answer 11

Parvovirus B19

-virion replicates best in rapidly dividing ERYTHROBLASTS, resulting in cell lysis

Question 12

Found as a contaminant in preparations of polio vaccines produced in monkey cell culture

Answer 12

SV40

-this POLYOMA VIRUS is typically a SIMIAN VIRUS, which can CAUSE TUMORS IN MICE, although no pathogenic effects have been reported in humans

Question 13

Infection results in the successive appearance of macules, papules, vesicles, and crusts all seen simultaneously

Answer 13

Varicella-zoster virus (VZV)

-severe infection can result in PNEUMONIA WITH MULTINUCLEATED GIANT CELLS

Question 14

Most common viral cause of congenital abnormalities in the USA

Answer 14

Cytomegalovirus (CMV)

-infected cells display characteristic “OWL EYE” intranuclear viral inclusions

Question 15

Major cause of epidemic conjunctivitis (Pink eye)

Answer 15

Adenovirus

-Various subtypes are also associated with PHARYNGITIS and GASTROENTERITIS

Question 16

DNA virus that encodes an RNA-dependent DNA polymerase (reverse transcriptase)

Answer 16

Hepatitis B virus (HBV)

-the virus produces its DNA genome through a SINGLE mRNA TRANSCRIPT, requiring the presence of a reverse transcriptase

Question 17

Appearance in the serum as Dane particles and as large amounts of filaments of excess surface antigen

Answer 17

Hepatitis B virus (HBV)

-the SURFACE ANTIGEN [HBsAg] is now produced by RECOMBINANT DNA TECHNOLOGY and is given as a VACCINE

Question 18

Leading cause of sporadic encephalitis in the USA

Answer 18

Herpes Simplex Virus-1 (HSV-1)

-Commonly affects the TEMPORAL LOBE

Question 19

Reactivation of latent viral infection in immunocompromised pts can result in Progressive Multifocal Leukoencephalopathy (PML)

Answer 19

JC virus

-this POLYOMAVIRUS causes FOCI OF DEMYELINATION surrounded by oligodendrocytes with viral inclusions

Question 20

The only DNA virus that replicates solely in the cytoplasm and that carries its own DNA-dependent polymerases

Answer 20

Poxvirus

-the LARGEST OF ALL VIRUSES, it appears BRICK-SHAPED by electron microscopy, and causes characteristic GUARNIERI INCLUSION BODIES when replicating in cells

Question 21

Associated with Reye syndrome when the accompanying fever is treated with aspirin

Answer 21

Varicella-zoster virus (VZV)

-Reye syndrome is an ACUTE ENCEPHALOPATHY associated with FATTY INFILTRATION of the LIVER, which is often FATAL

Question 22

Infection of a child results in a “slapped cheek” appearance

Answer 22

Parvovirus B19

-this SINGLE-STRANDED DNA virus causes ERYTHEMA INFECTIOSUM or FIFTH DISEASE

Question 23

This contagious virus causes benign epithelial tumors that appear as pearly, umbilicated nodules with a central caseous plug

Answer 23

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

Question 24

Most common cause of vesiculo-ulcerative lesions on the penis or vagina

Answer 24

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

Question 25

Causes cranberry-pigmented lesions on AIDS patients

Answer 25

Herpes virus 8

-KAPOSI SARCOMA is a TUMOR OF BLOOD VESSELS characterized by a DISARRAY OF VASCULAR channels filled with RBCs

Question 26

Infection with this virus is a leading cause of corneal blindness in the USA

Answer 26

Herpes simplex virus-1 (HSV-1)

-KERATOCONJUNCTIVITIS results in DENDRITIC ULCERS that can be visualized with FLUORESCEIN STAINING

Question 27

Major cause of retinitis, leading to blindness, in an immunocompromised patient

Answer 27

Cytomegalovirus (CMV)

-can also cause life-threatening INTERSTITIAL PNEUMONIA in such patients and HETEROPHIL-NEGATIVE INFECTIOUS MONONUCLEOSIS in immunocompetent individuals

Question 28

Major cause of infectious mononucleosis (kissing disease)

Answer 28

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