13 - Outbreaks

Question 1

Outbreak

Answer 1

Increase in number of cases of a disease or occurence of a disease in a new area

Question 2

Epidemic

Answer 2

Disease spreads rapidly to a large population, community or region

Question 3

Pandemic

Answer 3

When an infectious disease traverses continents, spreads around the world or to multiple countries

Question 4

Origins of disease outbreaks

Answer 4

• Can occur with both zoonotic and anthroponotic diseases
• Reasons are multifactorial and may combine to exacerbate the situation (e.g. over crowding, AMR, war, increased pathogenicity/transmissibility. etc)

Question 5

Overcrowding

Answer 5

• Many diseases expand in overcrowded areas
• E.g. those transmitted by contact, sexual contact or air
• Many diseases increase in over crowded cities, prisons, refugee camps

Question 6

Food and water
contamination

Answer 6

• Contamination of food and water will lead to rapid expansion of new cases
• Food often contaminated by poor hygiene
• Water contamination can lead to very large outbreaks (e.g. cholera, crytosporidiosis)

Question 7

Leptospirosis (weils disease)

Answer 7

• Bacterial disease of humans and animals
• Fever, severe headache, sore muscles, chills, vomiting, and red eyes.
• Can cause kidney failure, jaundice, bleeding, meningitis

Question 8

Antimicrobial resistance - why are many old diseases re-emerging due to increasing antimicrobial resistance

Answer 8

• Lack of development of new antimicrobials
• Use of antimicrobials for prophylaxis in farming
• Lack of multi drug therapy (MDR)
• Poor compliance and inappropriate medical use
• Microbial mutations are rapid, lack of MDT selects for resistant strains

Question 9

Disease outbreaks - weather

Answer 9

Many diseases especially those spread by aerosol or vectors are seasonal

Question 10

West Nile Virus

Answer 10

Mosquito vector borne viral disease that can cause encephalitis and meningitis

Question 11

Disease outbreaks - climate

Answer 11

Vector borne diseases are increasing with climate change, increasing the range of the vector

Question 12

Natural disasters / war

Answer 12

Cause poor hygienic conditions, isolate at risk populations, lead to overcrowding and often occur in regions with poor medical resources

Question 13

Change to virulence of pathogen

Answer 13

• Pathogens mutate faster than humans can adapt
• A single variant can lead to an increase in pathogenicity
• Generally over time pathogens become less pathogenic

Question 14

Change to transmissibility of pathogen

Answer 14

Pathogens mutate faster than humans can adapt, can lead to enhanced transmission and thus increase in cases

Question 15

Increase in susceptibility of hosts

Answer 15

Many outbreaks in hospitals, aged care facilities as there is a population of susceptible people

Question 16

Main difference between epidemic and pandemic

Answer 16

Is the spread of the disease occurrence

Question 17

Diseases most at risk of undetected global spread

Answer 17

Diseases with longer incubation times or asymptomatic carries