Viruses

Question 0

How do viruses differ from other microorganisms?

Answer 0

They cannot replicate outside of the host cell
They do not divide by binary fission
They are much smaller

Question 1

What is a virus?

Answer 1

A piece of genetic material (DNA or RNA) surrounded by a protein coat

Question 2

What are the four main types of virus structure?

Answer 2

Naked helical
Enveloped helical
Naked icosahedral
Enveloped icosahedral

Question 3

Give an example of a naked helical virus

Answer 3

Tobacco Mosaic Virus

there are no human viruses known

Question 4

Give an example of an enveloped helical virus

Answer 4

Measles
Mumps
Rabies

Question 5

Give an example of an enveloped icosahedral virus

Answer 5

Herpes

Question 6

Give an example of a naked icosahedral virus

Answer 6

Polio

Papillomavirus

Question 7

Give an example of a virus that is transmitted via the respiratory route

Answer 7

Influenza

Question 8

Give an example of a virus that is transmitted via the faecal-oral route

Answer 8

Hepatitis A

Question 9

Give an example of a virus that is transmitted via direct contact

Answer 9

Adenovirus

Question 10

Give an example of a virus that is transmitted via animal vector

Answer 10

Rabies

Question 11

Give an example of a virus that is transmitted sexually

Answer 11

HIV

Question 12

What are the routes of viral transmission?

Answer 12

Through the air
By direct contact
By animal vector
Through contaminated food/water
Through body fluids

Question 13

Give an example of a virus that causes acute infection followed by complete recovery

Answer 13

Rotavirus

Question 14

Give an example of a virus that causes acute infection followed by permanent damage

Answer 14

Poliovirus

Question 15

Give an example of a virus that causes acute infection followed by persistence in the patient

Answer 15

Herpes simplex virus type 1

Question 16

Give an example of a virus that causes congenital infection

Answer 16

Rubella

Question 17

Give an example of a virus that causes cancer

Answer 17

Epstein Barr virus

HPV

Question 18

Give an example of a virus that causes an emerging infection

Answer 18

HIV

Question 19

Give an example of a virus that has been completely eradicated

Answer 19

Smallpox

Question 20

Why was the discovery of tobacco mosaic virus important?

Answer 20

Because it was the first virus to be discovered, and it was key to the demonstration that viruses could pass through filters that retained bacteria.

Also economically important because of loss of tobacco crop

Question 21

Why were Walter Reed’s yellow fever experiments important?

Answer 21

It was the first human virus to be identified

It was believed to be caused by poor sanitation, but Reed proved it was transmitted by Mosquitos

It was the first example of written informed consent

The results allowed simple control measures, which allowed work to continue on the Panama Canal

Question 22

Name the 8 human herpes viruses and the primary infection caused by each one

Answer 22

Herpes Simplex Type 1 -gingivistomatitis
Herpes Simplex Type 2 -genital herpes
Cytomegalovirus -mononucleosis like illness
Varicella-Zoster virus -chickenpox
Epstein Barr virus -Infectious mononucleosis
Human Herpes Virus Type 6 -fever and rash
Human Herpes virus Type 7 -fever and rash
Human Herpes virus Type 8 -Kaposi’s sarcoma

Question 23

What disease does HSV1 cause when it is reactivated?

Answer 23

Cold sores

Question 24

What disease does HSV2 cause when it is reactivated?

Answer 24

Genital herpes

Question 25

What disease does VZV cause when it is reactivated?

Answer 25

Shingles

Question 26

What disease does EBV cause when it is reactivated?

Answer 26

``` Cancers: Non-Hodgkin's lymphoma Nasopharyngeal carcinoma Burkitt's lymphoma Post transplant lymphoproliferatove disorder ```

Question 27

What disease can be caused by complications with HSV2?

Answer 27

Herpes Simplex Encephalitis

Question 28

What are the complications associated with chickenpox in immunocompromised patients?

Answer 28

``` Pneumonia Hepatitis Pancreatitis Encephalitis Secondary skin infections ```

Question 29

What are the complications associated with cytomegalovirus in immunocompromised patients?

Answer 29

Hepatitis Colitis Retinitis

Question 30

What are the 5 major paramyxoviruses that infect humans?

Answer 30

``` Parainfluenza Measles Mumps Respiratory syncytial virus Human metapneumovirus ```

Question 31

What are the symptoms of Mumps?

Answer 31

Swelling of the sides of the face (infection of the salivary glands)

Question 32

What are the complications of mumps?

Answer 32

Orchitis (infection of the testicles) if contracted post-puberty Meningitis Encephalitis Foetal wastage if contracted during first trimester

Question 33

What are the symptoms of measles?

Answer 33

Fever Cough Conjunctivitis Red maculopapular rash

Question 34

What are the complications of measles?

Answer 34

Bronchopneumonia Otitis media (glue ear) Encephalomyelitis Sub-sclerosing pan encephalitis (very rare but fatal)

Question 35

Which patient groups are at the highest risk of complications associated with influenza viruses?

Answer 35

Elderly and very young

Question 36

Which organs are affected by a congenital rubella infection?

Answer 36

Eyes Ears Heart

Question 37

How does HIV cause disease?

Answer 37

By infecting and depleting CD4 and T helper lymphocytes Leads to the destruction of the immune system Allows opportunistic infections to develop (ie. Thrush)

Question 38

Give some of the opportunistic infections found with AIDS

Answer 38

Severe thrush (oral candidiasis) Pneumonia Tuberculosis Disseminated cytomegalovirus