Infectious disease

Question 1

Describe the stages of infection

Answer 1

1) Incubation
2) Prodromal
3) Acute
4) Convalescent
5) Resolution

Question 2

Describe some of the ways in which pathogens evade host defences in and out of the body

Answer 2

1) Avoiding phagocytes
2) Paralysing cilia
3) disrupts flora
4) Alteration of the surface of the microbe
5) the expression of decoy proteins
6) Acid resistance
7) Burn
8) Bites

Question 3

Define the key features of viruses, bacteria and fungi

Answer 3

Viruses

1) They have a protein coat containing DNA and RNA
2) Can not replicate outside a cell
3) It hijacks the host synthetic machinery

Bacteria

1) rigid wall, no organelles, invade tissues and multiply
2) can either be gram negative or gram positive
3) expression virulence factor

Fungi 
1)Free living ,non-motile, eukaryotic 
2)rarely cause infection
3)can exist in yeast or moulds
4 ) can cause skin infection e.g. athlete foot, ringworm

Question 4

Describe the importance of the chain of transmission and give examples of how this may be broken to prevent disease spread

Answer 4

The importance of the chain transmission helps by people knowing how they can be infected with a disease and how they can protect themselves from it and is that it help to prevent the spread of diseases.

This can be broken by the use of PPE, washing of hands, hand sanitizer, condoms and good hygiene.

Question 5

Describe in detail the pathogenesis of Varicella zoster

Answer 5

Varicella zoster is an example of an opportunistic pathogen. It is in the family of herpes. It transmitted through inhalation of infected respiratory secretions(coughing and sneezing) or contact with infectious skin lesions. It replicates in the lungs. It cause viremia and infection of the leucocytes .It has a latency period of 2 weeks. The clearance by immune response 1-2 weeks

Question 6

Describe in detail the pathogenesis of Influenza

Answer 6

Influenza cause acute respiratory inflammation in humans and symptoms such as high fever, body aches and fatigue. Influenza A and influenza B can cause respiratory illness in humans.  Wild aquatic birds are the natural reservoir of( IAV).Symptoms may include:
pyrexia 
Aches and pains
Cough
Headache
Diarrhoea/stomach aches
Nausea

Question 7

Explain the differences between antigenic drift and antigenic shift with reference to influenza

Answer 7

Antigenic drift

1) a small change in H or N
2) Gradual
3) Memory cell may be cross reactive or may not see virus

Antigenic drift

1) Sudden complete change in H or N
2) From animal source
3) No cross-protective immunity in the population

Question 8

Explain what is meant by a prophylactic and a therapeutic and give examples of each.

Answer 8

1

Question 9

Understand some key mechanisms of antibiotic function and antibiotic resistance.

Answer 9

1

Question 10

Understand what is meant by MRSA

Answer 10

1