Viral Diseases - Public health

Question 1

Define ‘reservoir of infection’

Question 2

Any person, animal, arthropod, plant, soil, or substance in which the disase agent normally lives or multiplies

Question 3

Define ‘transmission pathway’

Answer 3

Mechanism by which an infection agent is spread from a source (reservoir) to a susceptible individual

Question 4

Name the routes of infection

Answer 4

• From themselves
• From others - inderct or direct
• From animals - direct or indirect
• From the environment

Question 5

Name the routes of person to person spread, provided with one example for each

Answer 5

• Respiratory droplet spread e.g., influenza, COVID 19
• Aerosol transmission (<5 micron) e.g., TB
• Faecal oral spread e.g., dysentery
• Close contact e.g., meningococcal meningitis
• Sex e.g., gonorrhoea

Question 6

Name the routes of indirect person to person spread, provided with one example for each

Answer 6

• Foodborne e.g., staphylococcal food poisoning
• Waterborne e.g., cryptosporidium
• Via fomite (objects/materials likely to carry infection) e.g., dysentery
• Via needles e.g., Hepatitis B
• Vector borne e.g., malaria

Question 7

Name the routes of animal to human transmission, provided with at least one example for each

Answer 7

Livestock

• Via food – salmonella, E. coli

Domestic pets

• Direct – campylobacter
• Via faecal contamination of soil – Toxocariasis (an infection transmitted from animals to humans caused by the parasitic roundworms commonlyfound in intestines of dogs)

Wild animals

• Via ticks – Lyme disease

Question 8

Name the routes of environmment to human transmission, provided with at least one example

Answer 8

1. Built environment
   * Legionnaires’ disease (a lung infection you can get from inhaling droplets of water from things like air conditioning or hot tubs)
2. Natural environment

• Estuary syndrome (Pfiesteria)
• Naegleria meningitis (N. fowleri can cause an often fatal infection of the brain called naegleriasis)

Question 9

Describe the complicated transmission of:

a) Cholera
b) Campylobacter

Answer 9

a) Cholera = Environmental reservoir with person-to-person, foodborne and spread
b) Campylobacter = Environment and animal reservoirs with animal to human and animal spread

Question 10

How do you reduce susceptability of a population?

Answer 10

Immunisation

Question 11

How do you reduce infectious populations?

Answer 11

Diagnosis and treatment of infectious individuals

Question 12

How do you reduce person to person spread?

Answer 12

• Social distancing
• Handwashing
• Masks
• Food hygiene

Question 13

How do you prevent animal to human spread?

Answer 13

Wash hands

Question 14

Name 10 notifiable diseases

Answer 14

• Covid-19
• SARS-CoV-2