Week 9

Question 1

What are the types of viral infections?

Answer 1

Acute, Chronic, Latent, Tumor (oncogenic) viruses.

Question 2

Describe acute viral infections.

Answer 2

Develop rapidly, clear quickly, characterized by high virus progeny production

Can cause cytopathic effects like cell damage or death.

Question 3

Describe chronic viral infections.

Answer 3

Clear slowly or not at all, slower replication, and continuous viral shedding.

Question 4

What is a latent viral infection?

Answer 4

The virus remains dormant in the host cell for long periods before reactivating.

Question 5

How do tumor viruses affect cells?

Answer 5

They transform host cells into cancer cells by altering cell growth regulation.

Question 6

What is Herpes Simplex Virus (HSV)?

Answer 6

HSV causes initial asymptomatic or localized lesions, and can reactivate later, causing damage to organs like the liver, adrenal glands, or eyes.

Question 7

What is herpes virus simplex

Answer 7

typically causes cold sores and is usually associated with genital lesions

Question 8

How is HSV in the initial stages?

Answer 8

Asymptomatic or localized lesions

Question 9

What causes pain in HSV? How long is healing?

Answer 9

The vesicles filled with fluid that form

Healing is 2-3 weeks

Question 10

How does HSV travel?

Answer 10

Via sensory nerve

Question 11

Describe Varicella Zoster Virus (VZV).

Answer 11

causes chickenpox initially, and later shingles upon reactivation, which manifests as a painful rash along a nerve path.

Question 12

In shingles from VZV where do the vesicles form?

Answer 12

Around the chest or hips following the nerve path

Question 13

What is the Hepatitis B Virus (HBV)?

Answer 13

HBV infects liver cells, has a long incubation period

Question 14

How is HBV transmitted?

Answer 14

contaminated blood or sexually

Question 15

What does HBV genome form?

Answer 15

double stranded DNA circle in host cell nucleus and can integrate into host cell genome

Question 16

How does HBV increase carcinogen susceptibility?

Answer 16

By inducing mutations in host cell genes regulating cell growth

Question 17

What is the Hepatitis Delta Virus (HDV)?

Answer 17

HDV requires HBV for replication and is transmitted via blood products. It has an RNA genome.

Question 18

What are oncogenic viruses?

Answer 18

Viruses that can cause cancer, such as HPV, Epstein-Barr virus, and Hepatitis B.

Question 19

What role does HPV play in cancer?

Answer 19

HPV can integrate into host cell DNA, blocking p53 and Rb proteins that regulate the cell cycle, leading to cancer development.

Question 20

What is HPV?

Answer 20

DNA virus that infects epithelial cells, causing warts and genital cancers

Question 21

What HPV strains are oncogenic?

Answer 21

HPV16 and HPV18

Question 22

What is Epstein-Barr Virus (EBV)?

Answer 22

DNA virus, human herpes virus 4
Transmits via saliva

Question 23

How does EBV infect?

Answer 23

Initially insects epithelium of pharynx and salivary glands but then enters the bloodstream and invades B lymphocytes

Question 24

What else is EBV known as?

Answer 24

Mono or kissing disease

Question 25

How does EBV recover?

Answer 25

Cytotoxic T cells control the acute infection

Question 26

How is EBV connected to cancer?

Answer 26

causes infectious mononucleosis and is linked to cancers like lymphomas, especially under immunosuppression.

Question 27

What is a teratogenic virus?

Answer 27

A virus that can cause birth defects during pregnancy, like Cytomegalovirus (CMV) and Rubella, HSV 1 &2

Question 28

What test is done to identify teratogenic infections?

Answer 28

Series of tests called TORCH Toxoplasma Other viruses (HBV, VZV) Rubella Cytomegalovirus (cmv) Herpes simplex virus (HSV)

Question 29

How are teratogenic viruses transmitted?

Answer 29

Via placenta or during passage through the vaginal canal

Question 30

What is Zika Virus?

Answer 30

A mosquito-borne virus that can cause microcephaly and Guillain-Barré Syndrome, especially during pregnancy.

Question 31

What is microcephaly

Answer 31

Birth defect where the baby's head is much smaller due to it not developing properly or stopped growing

Question 32

What is GBS?

Answer 32

Immune response to ZIKA, causes muscle weakness and paralysis

Question 33

How is zika transmitted?

Answer 33

Bite of mosquito, maternal to fetal, sexual, lab exposure and blood transfusions

Question 34

How is Zikas syptoms?

Answer 34

Individual won't have them, or have mild ones (fever, rash, headache, joint pain, pink eye, and muscle pain) Incubation period is 3-14 days

Question 35

What is the main challenge with antiviral drugs?

Answer 35

We want to target the virus without damaging the host cells

Question 36

What are the stages in the viral life cycle targeted by antiviral drugs?

Answer 36

1) Entry, 2) Macromolecular Synthesis, 3) Assembly, 4) Release.

Question 37

How do antiviral drugs work?

Answer 37

Interferes with different steps of the virus cycle to stop it from multiplying

Question 38

What are attachment antagonists in antiviral therapy?

Answer 38

Peptide or sugar-like molecules that mimic viral attachment sites, preventing the virus from attaching to host cells.

Question 39

What is enfuvirtide

Answer 39

Blocks HIV from fusing with the host cell membrane

Question 40

What does the drug Maraviroc do?

Answer 40

Binds to CCR5 blocking HIV from attaching properly, preventing entry

Question 41

What is Amantadine used for?

Answer 41

Prevents viral uncoating, specifically for treating influenza infections.

Question 42

How do purine/pyrimidine analogs work?

Answer 42

They mimic building blocks inserted into viral DNA, halting virus replication. Ex: Acyclovir

Question 43

What is an NRTI (Nucleoside Reverse Transcriptase Inhibitor)?

Answer 43

targets HIV’s reverse transcriptase enzyme to block viral DNA synthesis. Ex: AZT which treats HIV

Question 44

How do NNRTIs (Non-Nucleoside Reverse Transcriptase Inhibitors) work?

Answer 44

bind near the active site of reverse transcriptase to inhibit its function, blocking HIV replication.

Question 45

What is the role of protease inhibitors in treating HIV?

Answer 45

block HIV's protease enzyme, preventing the production of mature viral proteins.

Question 46

What is ART (Antiretroviral Therapy)?

Answer 46

ART combines drugs like NRTIs and protease inhibitors to lower HIV levels and slow AIDS progression.

Question 47

What can stopping treatment of ART do?

Answer 47

Cause HIV levels to rise quickly again

Question 48

What is the purpose of Tamiflu in antiviral treatment?

Answer 48

Tamiflu inhibits the neuraminidase enzyme of the influenza virus, preventing new viral particles from being released.

Question 49

What are viroids and prions?

Answer 49

Viroids are RNA pathogens with no proteins Prions are infectious proteins that cause neurological diseases

Question 50

What are prion diseases?

Answer 50

Prion diseases are fatal brain disorders caused by misfolded proteins

Question 51

What are transmissible spongiform encephalopathies (TSEs)?

Answer 51

TSEs are diseases caused by prions, resulting in brain degeneration and the formation of holes in brain tissue, leading to a spongy texture.

Question 52

What are examples of prion diseases?

Answer 52

Chronic Wasting Disease (affecting deer and elk), Mad Cow Disease, Kuru, and Creutzfeldt-Jakob Disease (CJD).

Question 53

How are prion diseases transmitted?

Answer 53

Prions can spread through contaminated feed (Mad Cow Disease), saliva, urine, feces (Chronic Wasting Disease), and through cannibalistic practices (Kuru).

Question 54

What is the significance of spontaneous mutations in disease?

Answer 54

Spontaneous mutations are random changes in DNA that can lead to diseases, including cancers and genetic disorders like cystic fibrosis and sickle cell anemia.

Question 55

What are De novo mutations?

Answer 55

New mutations that are not inherited from parents