Topic 11: Infectious Diseases

Question 1

Why is HIV difficult to control?

Answer 1

There is a long symptomless stage where the disease can be transmitted without knowing

Question 2

Why is there not a vaccine for HIV?

Answer 2

Surface glycoproteins change regularly due to mutations

Question 3

What causes HIV?

Answer 3

Human Immunodeficency Virus - retrovirus (contains RNA)

Question 4

What does the HIV virus infect?

Answer 4

T helper lymphocytes and macrophages resulting in viral proteins being made

Question 5

How is HIV transmitted?

Answer 5

Bodily fluid exchange
- unprotected sex
- blood donation or transfusions
- mother to fetus via placenta
- mother to child via breast milk
- contaminated needles

Question 6

What are the 3 stages of HIV?

Answer 6

1. Acute phase - flu like symptoms
2. Chronic phase - symptomless
3. AIDs - die of opportunistic infections due to weak immune system

Question 7

Give 3 prevention or control techniques for HIV

Answer 7

• screen blood donations
• education programmes
• use of protection (barrier methods)
• contact tracing and HIV testing
• needle exchange programmesto provide sterile needles
• zidovudine drug
• antiretroviral therapy

Question 8

What causes cholera?

Answer 8

Vibrio cholerae - bacterium

Question 9

What does the cholera bacteria infect?

Answer 9

Walls of small intestines, releasing toxins

Question 10

How is cholera transmitted?

Answer 10

Water and food borne due to faecal contamination

Question 11

What are signs of cholera?

Answer 11

• severe watery diarrhoea
• severe dehydration
• loss of water and salts

Question 12

Give 3 prevention techniques for cholera

Answer 12

• provide sewage treatment
• build sanitation systems in homes
• provide clean, chlorinated piped drinking water
• vaccination programmes

Question 13

Give 3 control techniques for cholera

Answer 13

• oral rehydration therapy
• antibiotics (tetracycline)
• contact tracing
• cholera vaccine

Question 14

Give 3 places where cholera outbreaks may occur

Answer 14

• in poverty
• slums
• civil wars
• places with poor mediacl care
• after natural disasters

Question 15

What causes tuberculosis?

Answer 15

Mycobacterium tuberculosis
Mycobacterium bovis

Question 16

What do the mycobacterium infect with tuberculosis?

Answer 16

The lungs

Question 17

How is tuberculosis transmitted?

Answer 17

• airborne, aerosol droplets from infected people, spread in overcrowding places
• contaminated meat
• unpasteurised milk

Question 18

What are symptoms of tuberculosis?

Answer 18

• chest pain
• fever
• a persistent cough
• coughing blood

Question 19

Give 3 incidences where tuberculosis is spread

Answer 19

• drug resistant strains
• HIV/AIDS pandemic
• overcrowded conditions
• breakdown of programmes among the homeless, drug users and LEDCs
• antibiotics not being completed

Question 20

Give 3 prevention techniques for TB

Answer 20

• contact tracing and testing
• quarantine
• DOTS programme (mix of 3 to 4 drugs)
• use of bedaquiline to treat extremely resistant TB

Question 21

True or false? There isn’t a TB vaccine for adults

Answer 21

True, only the BCG vaccine for kids

Question 22

How is malaria spread?

Answer 22

• female Anopheles mosquitoes
• blood transfusion or unsterile needles
• mother to fetus across placenta

Question 23

What causes malaria?

Answer 23

Plasmodium falciparum - protoctist

Question 24

What does malaria infect?

Answer 24

Liver, red blood cells and brain

Question 25

What are symptoms of malaria?

Answer 25

• fever
• shivering
• sweating
• muscle pain
• anaemia

Question 26

Give the 3 ways to prevent malaria

Answer 26

1. Reduce the number of Anopheles mosquitoes
2. Avoid being bitten
3. Use prophylactic drugs

Question 27

Give 3 ways to control malaria

Answer 27

• biological control
• use prophylactic drugs
• use a dipstick for diagnosis
• use vaccine mosquirix
• vaccination programmes