Epidemiology and Control Terminology

Question 1

Epidemic (Pattern of Infection)

Answer 1

• Unusually high number of infected individuals in a population at one time.
• Can range from the small scale up to nationwide
• e.g. Ebola in West Africa

Question 2

Pandemic (Pattern of Infection)

Answer 2

• a world-wide epidemic

* e.g. HIV or influenza

Question 3

Endemic (Pattern of Infection)

Answer 3

• Constantly present, usually affecting a small proportion of the population
• e.g. MRSA is endemic to many hospitals

Question 4

Sporadic (Pattern of Infection)

Answer 4

• Individual cases in geographically separate areas

* Incidents are not related

Question 5

Outbreak (Pattern of Infection)

Answer 5

• A number of cases in a short period of time in the same area
• Assumed to be related

Question 6

Carrier

Answer 6

• Infected individual showing no obvious sign of disease

Question 7

Acute carrier

Answer 7

• Before symptoms appear

* Carrier state of short duration

Question 8

Chronic carrier

Answer 8

• Long term
• May have recovered from the disease but still harbour pathogens
• May be asymptomatic
• E.g. Hepatitis, TB, typhoid fever

Question 9

Immunisation

Answer 9

• Using vaccines or antibody preparations to provide immune protection against infectious diseases

Question 10

Passive (antibody preparation)

Answer 10

• Preformed antibodies created in another host
• Protect individual exposed to disease
• Work immediately but short-term protection

Question 11

Active (vaccines)

Answer 11

• Modified / purified pathogens or their product
• Stimulate host to produce own specific immunity
• A few weeks lag before protection, but long-lasting