General virology and DNA viruses

Question 1

Vaccines

Answer 1

Live attenuated: smallpox, yellow fever, VZV, Sabin’s, MMR, influenza
- no booster needed for live attenuated

Killed: rabies, Influenza, Salk, and HAV

Recombinant, HBV, HPV

Question 2

DNA viral genome

Answer 2

All DNA viruses are dsDNA
-EXCEPTION: parvoviridae (partial and small)

All DNA viruses are linear
-EXCEPTION: papilloma, polyoma, hepadenavirus (circular)

Question 3

RNA viral genomes

Answer 3

All RNA viruses are ssRNA
-EXCEPTION: Reoviruses (repeat-o)

Positive strand:
I went to RETRO TOGA party, where I drank FLAVored CORONA and ate HIPPY CALIfornia PICkles.

Question 4

Naked viral genome infectivity

Answer 4

Purified nucleic acid of most DNA and + ssRNA are infectious
-EXCEPTIONS: poxviruses and HBV

Naked nucleic acid of - ssRNA and dsRNA are not infectious, as they require polymerases to infection

Question 5

Viral replication

Answer 5

DNA: all in the nucleus
EXCEPTION: poxviruses

RNA: all replicate in the cytoplasm
EXCEPTION: influenza and retrovirus

Question 6

Viral envelope

Answer 6

Naked: papillomavirus, adenovirus, picornavirus, polyomavirus, calcivirus (noro), parvovirus, reovirus, and hepevirus

“Give PAPP smear and PCR to a naked HEP-ee)

Generally, envelopved viruses acquire their envelop as they exit.
EXCEPTION: herpes, which acquire envelop from nuclear membrane.

Question 7

DNA virus characteristics

Answer 7

Hepadna, herpes, adeno, pox, parvo, papilloma, polyoma

All double stranded; except, parvo (single)
All linear; except papilloma/polyoma(circular, supercoiled), and hepadna(circular, incomplete)

All icosahedral; except pox (complex)
All replicate in the nucleus; except pox (carries own DNA dependent RNA polymerase).

Question 8

Herpes

Answer 8

DS and linear
HSV1, HSV3, VZV (3), EBV (4), CMV (5), KSHV (8)
HHV6: Roseola (exanthem subitum)

EBV: mono, Burkitt’s, Hodgkin’s

Question 9

Hepadnavirus

Answer 9

DS and partial circular

HBV: carries RT

Question 10

Adenovirus

Answer 10

DS and linear, no ENV
Febrile pharyngitis (sore throat, acute hemorrhagic cystitis)
Pneumonia, conjunctivitis

Question 11

Parvovirus

Answer 11

SS and linear, NEGATIVE strand, NO ENV

the smallest DNA virus

B19:

• aplastic crises in sickle,
• slapped cheek in children
• RBC destruction in fetus => hydrops fetalis and death
• erythema infectiosum (fifth disease)
• pure RBC aplasia
• rhumatoid arthritis like symptoms in adults

Question 12

Papillomavirus

Answer 12

DS circular, no ENV
HPV 
Warts: 1,2,6,11
CIN, 
Cervical cancer; 16, 18

Question 13

Polyomavirus

Answer 13

DS circular, no ENV

JC: PML in HIV
BK: transplant patient, commonly targets kidney

BK: bad kidney

Question 14

Poxvirus

Answer 14

DS and linear, YES ENV

Largest DNA virus

Smallpox, though eradiated, implicated germ warfare
Vaccinia: cowpox (milkmaid’s blister)
Molluscum contagiosum: flesh colored dome lesions with central dimple containing custard things.

Question 15

HSV1

Answer 15

gingivostomatits,
keratoconjuctivitis,
temporal lobe encephalitis (most common cause of sporadic encephalitis in the US)
herpes labialis

Latent in trigeminal ganglia

Transmission: respiratory and saliva

Question 16

HSV2

Answer 16

Herpes genitalis,
neonatal herpes

Latent in sacral ganglia
Transmission: sex, perianal

Question 17

VZV

Answer 17

Zooster,
encephalitis,
pneumonia

Latent in dorsal root or terminal ganglia
Transmission: respiratory secretion

Question 18

EBV

Answer 18

Mono, Burkitt/Hodgkins, NPC

Latent in B cells
Transmission: respiratory secretion, saliva

Question 19

CMV

Answer 19

Congenital infetion,
Mono with negative monospot
pneumonia,
retinitis
Infected cells with owl's eye inclusion

Latent in mononuclear cells
Transmission: congenital, transfusion, sex, saliva, urine, transplant.

Question 20

HHV 6 (no HHV7)

Answer 20

Roseola: high fevers for several days that can cause seizure, followed by a diffuse macular rash

Transmission: not determined

Question 21

HHV 8

Answer 21

KS, via sex

Question 22

HSV identification

Answer 22

PCR the test of choice
Tzanck: spear of an open skin vesicle to detect mutinucleated giant cells seen in HSV1,2, VZV.

Infected cells also have intracellular Cowdry A inclusions.

Question 23

EBV

Answer 23

mono, fever, HSM, pharyngitis, and LAD (esp posterior cervical nodes)

Incidence 15-20 year sof age

Atypical lymphocytes (HUGGING RBCs) seen in peripheral blood smear are not infective B cells but rather reactive cytotoxic T cells.

Positive monospot: heterophile Ab detected by agglutination of sheep or horse RBCs.

Hodgkins, Burkitt,s NPC.