30.1 - Relative Importance of Infection as a Cause of Morbidity and Mortality

Question 1

What is the importance of infectious diseases in evolution?

Answer 1

Infectious diseases tend to kill people before they reach reporoductive maturity, so they have a large effect on natural selection, thus altering the gene pool.

Question 2

Roughly what fraction of deaths globally are due to infectious diseases?

Answer 2

Around 15 - 20%

Question 3

Compare the percentage of global deaths caused by infectious diseases, cardiovascular diseases and cancers.

Answer 3

From most to least prevalent causes of death:

• Cardiovascular diseases
• Infectious diseases
• Cancers

Question 4

In what population and age subsets are infectious disease deaths especially common?

Answer 4

Common in children under 5 in less developed countries.

Question 5

What is this difference in leading mortality between wealthy and poor countries?

Answer 5

Wealthy western countries: death not from infectious diseases but rather cardiovascular issues due to longer lifespan and diet
Poor countries: Infectious diseases

Question 6

What is the age distribution of getting an infectious disease? Why?

Answer 6

Minimal link between elderly people and getting infectious disease (most infected groups 20-40 due to increased social exposure)

Question 7

Which age groups have the highest mortality with infectious disease?

Answer 7

Very young and very old due to poorer immune system

Question 8

Which diseases cause the highest mortality in low income countries?

Answer 8

Diarrhoeal diseases
Tuberculosis
Respiratory infections