Viral Pathogenesis II

Question 1

example of viral exanthem

Answer 1

HPV

Question 2

what are some low risk and high risk HPV

Answer 2

low risk - genital warts

high risk - premalignant lesions

Question 3

genome of HPV and what they infect

Answer 3

circular 8kB dsDNA

infect epithelial cells

Question 4

what is Epidermodysplasia verruciformis (EV)?

Answer 4

rare inherited disorder that exposes pt to widespread HPV infection and cutaneous squamous cell carcinomas

Question 5

symptoms from viral disease arise from what

Answer 5

tissue damage or inflammatory responses

Question 6

in the CNS, what does viral infection lead to

Answer 6

most do not cause disease but some can be serious

Question 7

how do you identify the viral agent in CNS viral infections

Answer 7

CSF fluid or biopsy

Question 8

major route for some viruses to spread

Answer 8

sex

don’t forget oral and GI are the common site for most viral infections

Question 9

what is of particular concern in STIs

Answer 9

asymptomatic shedding – so people can unknowingly pass it to their partners because they do not show any symptoms

Question 10

CNS and STI viral examples

Answer 10

HHV-1 and 2

Question 11

what does HHV-1 and 2 share

Answer 11

DNA homology, antigenic determinants, tissue tropism and disease symptoms

Question 12

type of virus that can stay in the body indefinitely

Answer 12

Ubiquitous, large, ds DNA, enveloped icosahedral virus aka HHV-1 and 2

Question 13

importance of the enzymes that HHV-1 and 2 encode

Answer 13

encode enzyme that are good antiviral targets

Question 14

what types of cells do HHV-1 and 2 infect and replicate

Answer 14

mucoepithelial cells

Question 15

resultant phase of HHV-1 and 2 infections

Answer 15

– lytic (most cells: Cowdry type A inclusion bodies, syncytia)
– persistent (lymphocytes and macrophages)
– latent infections (neurons)

Question 16

pathogenesis of HHV-1 and 2

Answer 16

Virus blocks effects of interferon, prevents CD8 T-cell recognition of infected cells, escapes antibody neutralization and clearance by going into “hiding” during latent infection

Question 17

how does recurrence of HHV-1 and 2 occur

Answer 17

in response to various stimuli

Question 18

eyes are another site of viral diseases – how is it transmitted

Answer 18

direct contact or viremic spread

Question 19

example of viral eye infection

Answer 19

HHV-5 (CMV)

Question 20

most prevalent cause of congenital diseases

Answer 20

HHV-5 (CMV)

Question 21

what is associated with CMV in newborns

Answer 21

chorioretinitis

10% of affected newborns show clinical evidence of disease

Question 22

what are some evidence of CMV in newborns

Answer 22

small size, thrombocytopenia, microcephaly, intracerebral calcification, jaundice, hepatosplenomegaly, and rash

Question 23

examples of viruses transmitted in blood

Answer 23

– Hepatitis B, C, G, D 
– HIV
– HTVL-1
– HHV-5 (CMV)
– HHV-4 (EBV)
– West Nile encephalitis virus

Question 24

in hematological diseases of viral infections, lymphocytes and macrophages are targets for what type of viruses

Answer 24

those that establish persistent infections

transient viral expression of some viruses elicit large T cell responses

Question 25

some additional modes of transmission for viral diseases

Answer 25

– congenital, neonatal, perinatal infections – transfusion, transplantation – arthropods, other animals

Question 26

some properties of chronic viral infections

Answer 26

– immune system has trouble resolving infections | – most DNA viruses and retroviruses cause latent infections 􏰁recurrence

Question 27

some properties of oncogenic viruses

Answer 27

– viruses can carry copies of genes in which altered expression results in loss of growth control – viruses can modulate the cell’s regulatory factors

Question 28

consequences of viral infections in immunocompromised people

Answer 28

* Atypical and more severe presentation * Deficient cell-mediated immunity * Severe T-cell deficiencies * Immunoglobulin A deficiency or hypogammaglobulinemia

Question 29

what are host cell changes in response to viral infection

Answer 29

``` cytopathic effects – Rounding – Inclusion bodies – Cell lysis, Necrosis, Apoptosis, etc. – Syncytia formation – Transformation ```

Question 30

difference between visualizing a virus and its effects

Answer 30

you need an electron microscope to see viruses but you can visualize its effects without it