Chp. 13 B

Question 1

Which hepatitis virus is DNA and which are RNA?

Answer 1

DNA: Hepatitis B
RNA: Hepatitis A and C

B and C more dangerous

Question 2

What are the clinical features of hepatitis infection?

Answer 2

Jaundice US, eyes turn yellow, B and C can cause cancer, fever

Question 3

How can Hepatitis B infection be prevented?

Answer 3

There is a vaccine available for it derived from surface antigen from cloned yeast- 3 doses with boosters

Those allergic to yeast takes vaccine derived from purified sterile antigen extracted from carrier blood

Question 4

What does adenovirus cause?

Answer 4

Causes:
- colds
- pharyngitis
- conjunctivitis
- keratoconjunctivitis
- acute hemorrhagic cystitis

Question 5

How is adenovirus transmitted?

Answer 5

By respiratory and ocular secretions

Question 6

True or false:

Adenovirus is oncogenic

Answer 6

True and false!

Adenovirus can cause cancer, but not to humans

Question 7

What does human papilloma virus cause?

Answer 7

Papilloma (warts)

Question 8

Do papilloma viruses cause cancer?

Answer 8

Yes. 9 HPV types increase risk for developing reproductive cancer

Question 9

Can papilloma viruses be prevented? How?

Answer 9

Yes, there are 2 effective HPV vaccines

Question 10

How are RNA viruses separated?

Answer 10

Enveloped:
- Single stranded (SS) genome or Single stranded genome encodes reverse transcriptase (retroviruses)
- SS: segmented or nonsegmented

Non-enveloped:
- Single stranded or double stranded

Question 10

What is the difference between the antigenic drift and antigenic shift?

Answer 10

Antigenic drift is the constant mutation of a virus whereas antigenic shift is the sudden unexpected mutation that leads to a new strain

Question 11

How do glycoprotein spikes hemagglutinin and neuraminidase contribute to the virulence of influenza virus?

Answer 11

They frequently undergo genetic changes decreasing the effectiveness of the host’s immune memory response

Question 12

Why is it necessary to get a flu shot every year?

Answer 12

The influenza virus is constantly changing and mutating, so vaccines do not work against it and must constantly be updated

Question 13

How are flu viruses named?

Answer 13

They are named based on their type (A,B,C,D), followed by place the virus was isolated, followed by virus strain number, year isolated, then the virus subtype

eg. A/Sydney/05/97 (H3N2) - A type A influenza virus isolated in Sydney in 1997, strain 05, with the H3 and N2 subtypes.

Question 14

What antiviral drugs treat influenza?

Answer 14

• Amantadine
• Rimantadine
  ^^ less effective
  vv More effective
• Zanamivir (relenza)
• Oseltamivir (tamiflu)

Question 15

How is the mumps virus transmitted?

Answer 15

through respiratory transmission

Question 16

What is the natural reservoir for measles?

Answer 16

Humans

Question 17

How is measles infection spread?

Answer 17

transmitted by respiratory aerosols

Question 18

How is measles infection spread, symptoms and prevented?

Answer 18

It invades the respiratory tract

Symptoms:
- sore throat
- dry cough
- headache
- conjunctivitis
- lymphadenitis
- fever
- Koplik spots US

Vaccine available: MMR (attenuated viral vaccine)

Question 19

What is the prognosis for untreated rabies?

Answer 19

certain death

Question 20

How do humans contract rabies?

Answer 20

Spread by wild and domestic mammals by bites, scratches, and inhalation of droplets

Question 21

What is the treatment for rabies infection?

Answer 21

ONLY IF NO SYMPTOMS HAVE APPEARED:
- immediate and thorough wound cleansing
- Rabies immunoglobulin (HRIG)
- Rabies vaccine (4 doses over two weeks)

Question 22

What is rubella? What is the natural reservoir for it?

Answer 22

Single stranded RNA virus with loose envelope
Humans are the natural resevoirs

Question 23

What is another name for rubella?

Answer 23

German measles

Question 24

How is rubella spread and how do you prevent it?

Answer 24

Spread through contact with respiratory secretions Prevent using attenuated viral vaccine MMR

Question 25

How does HIV multiply within immune cells?

Answer 25

They replicate only the CD4 (aka helper t cells) plus a coreceptor. It then uses part of the CD4 cell to create long chains of HIV proteins, allowing HIV to build more and more particles

Question 26

How and why do T cells die during an HIV infection?

Answer 26

HIV specifically targets those cells and causes activation-induced cell death

Question 27

Describe the following anti-AIDS drugs: - Reverse transcriptase inhibitors - Protease inhibitors - Fusion inhibitors

Answer 27

RTI: block HIV's reverse transcriptase enzyme, which prevents the virus from replicating and integrating into the host's DNA PI: block HIV's protease enzyme, which prevents proper HIV assembly and replication FI: block the entry of HIV into host cells by preventing the virus from fusing with the host cell membrane

Question 28

How do retroviruses differ from most RNA viruses?

Answer 28

Retroviruses use reverse transcriptase to convert their RNA into DNA

Question 29

What is yellow fever? What are the symptoms?

Answer 29

mosquito borne viral disease- eliminated in the US Symptoms - Acute fever - headache - muscle pain; may progress to oral hemorrhage - nosebleed - vomiting - jaundice - liver and kidney damage

Question 30

What virus causes yellow fever?

Answer 30

The yellow fever virus from the Flaviviridae family

Question 31

What is dengue fever and what causes it?

Answer 31

flavivirus carried by the Aedes mosquito

Question 32

What are emerging diseases? Name 4

Answer 32

Infections that have recently appeared within a population or whose incidence and geographical range is rapidly increasing - COVID - SARS - measles - yellow fever

Question 33

What causes polio? How is it transmitted?

Answer 33

Caused by the poliovirus and is transmitted through feces or respiratory droplets

Question 34

How does infection with a polio virus progress?

Answer 34

It enters through the mouth, multiplies in the intestines, and can spread to the CNS, causing inflammation and damage to motor neurons. Can lead to muscle weakness, paralysis, and even death

Question 35

What diseases do prions cause?

Answer 35

- Scrapie in sheep and goats - Bovine spongiform encephalopathis (BSE) aka mad cow disease - Wasting disease in elk - Creutzfeldt- Jakob Syndrome (CJS) in humans

Question 36

What are symptoms of COVID 19? What virus causes it?

Answer 36

Common: fever, dry cough, tiredness Less common: rash, aches and pains, discoloration of fingers and toes, headache, loss of taste and smell Coronavirus causes COVID 19