Harmful Microorganisms

Question 1

How can diseases be spread?

Answer 1

• Microbes can be spread in food (salmonella), can be controlled by food hygiene
• Microbes can be spread in water (cholera), can be controlled by water treatment
• Microbes can need direct contact, can be controlled by barrier methods
• Microbes can be spread in airborne droplets (influenza), can be controlled by tissue and isolation of patients

Question 2

What are the stages of infectious diseases?

Answer 2

1) Microbe enters body
2) Reproduces many times without causing symptoms (incubation period)
3) Microbes cause the production of toxins
4) Toxins cause symptoms, eg. fever

Question 3

Why is disease common in disaster areas?

Answer 3

• Destruction of sewage systems leads to water contamination
• Damage to electricity causes fridges to stop working and food to decay
• Shortage of staff or hospitals damaged
• Large numbers of people living close together

Question 4

Who made discoveries in preventing diseases?

Answer 4

• Louis Pasteur: proved microbes in air could make food go bad
• Joseph Lister: invented first aseptic technique by putting carbonic acid on a wound to prevent infection
• Alexander Fleming: discovered penicillin

Question 5

How do we prevent antibiotic resistance?

Answer 5

• Only prescribe when necessary

- Advise to finish dose so partially resistant bacteria are also killed