Module 4: Causes of Morbidity & Mortality

morbidity

sickness

communicable disease

infectious disease

• agent: pathogen

• vector: living creature that carries pathogen

• enormous burden globally

• always changing, new threats

• epidemic/pandemic potential

• a single exposure is sufficient to cause illness

• symptoms develop shortly after exposure

non-communicable disease

chronic disease

• agent: carcinogens, cholesterol, sodium, sugar

• vector: an object that carries agent

• leading causes of death

• reduce quality of life, often long-term conditions

• multiple causes/risk factors

• manageable, but not completely curable

epidemiologic triad

disease/injury results from an interaction of:

1. host (susceptible human)

2. agent (tells you the classification of communicable, non-communicable, or injury)

3. environment (physical & social)

4. sometimes vector (carrier)

injury

agent: energy

• physiological outcome in terms of damage to the body

• predictable & preventable

• leading cause of death & YPLL

2 types of injury

1. traumatic injury: occurs immediately upon transfer of energy to body

2. overuse injury (musculoskeletal disorders): occurs overtime

aerosols

water droplets produced when an infected person coughs/sneezes

chain of infection

1. pathogen

2. reservoir (where pathogen lives/multiplies)

3. method of transmission (vector)

4. susceptible host

retrovirus

virus that uses RNA as its genetic material

antibiotic resistance

ability of bacteria to survive & multiply despite the presence of an antibiotic

prions

abnormally folded proteins that can induce other proteins to misfold

atherosclerosis

condition in which fatty deposits (plaque) builds inside arteries

sensitivity

a test’s ability to correctly identify people who do have a disease

burden of disease

the total loss caused by a particular health condition

1. mortality

2. morbidity

3. composite measures (mortality + morbidity)

4. economic costs

disability adjusted life years (DALYs)

combines YPLLs w/ years lived w/ disability (YLDS)

economic costs

(number of cases) x (average cost per case)

2 ways to counting number of cases

1. incidence-based approach: new cases in a specified period of time

2. prevalence-based approach: look at all existing cases

2 ways to estimating average cost

1. human capital approach

2. contingent valuation approach