DNA VIRUSES (NAKED DNA VIRUSES)

Question 1

All DNA viruses have double stranded DNA EXCEPT

Answer 1

Parvovirus

Question 2

All DNA viruses have linear DNA EXCEPT

Answer 2

Papilloma, Polyoma, and Hepadna

Question 3

All DNA viruses are icosahedral EXCEPT

Answer 3

Poxvirus

Question 4

All DNA viruses replicate in the nucleus EXCEPT

Answer 4

Poxvirus

Question 5

What does the Latin term “parvus” mean?

Answer 5

Small

Question 6

Among which type of animals is Parvoviridae widely distributed?

Answer 6

Warm-blooded animals.

Question 7

Which is the single human pathogen among the Parvoviridae?

Answer 7

Parvovirus B-19.

Question 8

A nonenveloped, icosahedral, single-stranded DNA virus that may appear spherical on electron microscopy.

Answer 8

Parvovirus

Question 9

What are the major sites of viral replication for Parvovirus

Answer 9

Adult bone marrow and fetal liver cells.

Question 10

What is another name for Fifth disease caused by Parvovirus B-19?

Answer 10

Erythema infectiosum.

Question 11

What are the symptoms of Fifth disease?

Answer 11

Bright red cheek rash (slapped cheeks) with fever, coryza, and sore throat.

Question 12

What can Parvovirus B-19 cause in patients with underlying hemoglobinopathies?

Answer 12

Aplastic crisis, which is transient but severe in conditions like sickle cell anemia, thalassemia, or spherocytosis.

Question 13

What are the effects of fetal infection with Parvovirus B-19 during the first and second trimesters?

Answer 13

First trimester: fetal death;
Second trimester: hydrops fetalis.

Question 14

What are the two phases of biphasic illness caused by Parvovirus B-19?

Answer 14

The first phase includes:
marked fever, malaise, myalgia, and chills,

The second phase includes:
rash and arthralgia.

Question 15

When do IgM and IgG antibodies appear after Parvovirus B-19 infection?

Answer 15

IgM antibodies appear within 7 days, followed by IgG at approximately 14 days.

Question 16

How is Parvovirus B-19 diagnosed in the laboratory?

Answer 16

By parvovirus-specific IgM or virus-specific IgG antibody testing with paired acute and convalescent sera or by detection of viral DNA using PCR.

Question 17

Can Parvovirus B-19 be cultivated in typical clinical virology laboratory cells?

Answer 17

No, it cannot be cultivated in the typical cells available in clinical virology laboratories.

Question 18

Medium-sized (70-90 nm), icosahedral, nonenveloped, double-stranded, linear DNA viruses.

Answer 18

Adenovirus

Question 19

What are the most common clinical manifestations associated with adenovirus infection?

Answer 19

Respiratory and gastrointestinal diseases.

Question 20

How is adenovirus most commonly transmitted (MOT)?

Answer 20

Through aerosolized droplets or as airborne particles.

Question 21

How is respiratory disease caused by adenovirus usually acquired?

Answer 21

respiratory secretions, stool, or fomites.

Question 22

very stable and can remain viable for weeks at variable temperatures on surfaces and in liquid solutions.

Answer 22

Adenovirus

Question 23

What is the incubation period for respiratory disease caused by adenovirus?

Answer 23

2-14 days.

Question 24

What are some common respiratory conditions caused by adenovirus?

Answer 24

Colds, tonsillitis, pharyngitis, pharyngoconjunctival fever, croup and Epidemics in military recruits

Question 25

How can adenovirus be detected in the laboratory?

Answer 25

From respiratory secretions or stool in cell culture using various epithelial cell lines.

Question 26

What confirmatory follow-up tests are used for adenovirus detection?

Answer 26

Indirect fluorescent antibody (IFA) technique or enzyme immunoassay (EIA).

Question 27

What characteristic cytopathic effect (CPE) does adenovirus produce?

Answer 27

A grapelike cluster cytopathic effect known as Cowdry Type B intranuclear inclusions.

Question 28

Small, nonenveloped, circular, double-stranded DNA viruses.

Answer 28

Papillomavirus

Question 29

In which species can Papovaviridae cause infections?

Answer 29

Humans, dogs, cattle, monkeys, and many other species.

Question 30

What are Human Papillomaviruses (HPV) known to cause?

Answer 30

Human warts.

Question 31

What is the tissue tropism of HPV?

Answer 31

Either cutaneous or mucosal tissue.

Question 32

What cells do HPV infect and what do they induce?

Answer 32

HPV infects squamous cells and induces the formation of cytoplasmic vacuoles (koilocytes).

Question 33

What are the functions of the E6 and E7 genes in HPV?

Answer 33

E6 inhibits p53
E7 inhibits Rb,
leading to the inactivation of tumor suppressor genes.

Question 34

Which HPV types are associated with plantar warts?

Answer 34

HPV-1.

Question 35

Which HPV types are associated with common warts of the hands?

Answer 35

HPV-2 and HPV-4.

Question 36

Which HPV types are associated with genital warts (condyloma accuminata)?

Answer 36

HPV-6, HPV-11, and others.

Question 37

How many types of HPV cause virtually all cases of cervical cancer, and which types cause more than 60% of cases?

Answer 37

-Fifteen to twenty types of HPV cause virtually all cases of cervical cancer

-with types 16 and 18 causing more than 60% of cases.

Question 38

Which HPV type is associated with a subset of cancers of the oropharynx and penile cancer in males?

Answer 38

HPV-16.

Question 39

Which HPV type is associated with adenocarcinoma?

Answer 39

HPV-18.

Question 40

What is the most prevalent sexually transmitted viral disease in the United States?

Answer 40

HPV infection.

Question 41

How is HPV infection detected?

Answer 41

-Using histopathologic (cutaneous biopsy) or cytologic (cells) examination

-DNA probe assays for identification of specific genotypes in infected epithelial cells.

Question 41

What are the vaccines available for HPV prevention?

Answer 41

Cervarix, Gardasil, and Gardasil-9.