Exam 2 Module 5

Question 1

what is epidemiology?

Answer 1

discipline that describes, quantifies, and postulates causal mechanisms for diseases in populations, and develops methods for the control of diseases

Question 2

epidemiology is based on which two fundamental assumptions?

Answer 2

1. the occurrence of disease is not random (ex: various factors influence the likelihood of developing disease)
2. the study of populations enables the identification of the causes and preventative factors associated with disease

Question 3

what is the purpose of epidemiology?

Answer 3

• examines determinants and distribution of disease, disabilities, morbidity, and mortality, as well as health
• specialized form of scientific research
  
  • provides health care workers with a body of knowledge on which to base their practice and methods for studying new and existing problems

Question 4

what are the 3 components of the epidemiological triangle?

Answer 4

1. host –> the actual or potential recipient or victim of the disease. genetic make up, age, sex, nutritional choices, lifestyle factors, race, exercise level, health knowledge, motivation to achieve optimal wellness
2. agent –> the factor that causes disease. Agents may be biological (e.g., bacteria and fungi), chemical (e.g., gases and natural or synthetic compounds), nutritional (e.g., food additives), or physical (e.g., ionizing radiation), psychosocial
3. environment –> includes all external factors, other than the host and agent, that influence health. The environment may be categorized as the social environment (e.g., economic, legal, and political), the physical environment (e.g., weather conditions), or the biological environment (e.g., animals and plants)

Question 5

give a specific example of the epidemiologic triad

Answer 5

a case of lung cancer may be considered. The host is the person who developed lung cancer. He or she may have had the habit of smoking for many years. The agents are the smoke and the tars and toxic chemicals contained in the tobacco. The environment may have been the workplace where smoking on the job was permitted and sites where cigarettes or other tobacco products were readily available.

Question 6

what is causality?

Answer 6

the relationship between a cause and its effect.

Question 7

difference between the chain of causation & web of causation

Answer 7

chain of causation –> This model still includes the triad of Host, Agent and Environment & begins by identifying the reservoir (i.e., where the causal agent can live and multiply)
web of causation –> health focus moved from Communicable, Infectious to Non-Infectious Disease and Conditions. The linear model did not work as well due to the multiple causations present especially in non-Infectious health issues. We don’t just use this for disease states but also for other events impacting health such as auto accidents, suicide, etc.

Question 8

give an example using the chain of causation model

Answer 8

MALARIA –> infected humans are the major reservoir for the parasitic agents, although certain nonhuman primates also act as reservoirs

Question 9

give an example using the web of causality model

Answer 9

men who do get a PSA test as part of preventative care vs. those that don’t

Question 10

what is incidence? why is it important?

Answer 10

refers to all new cases of a disease or health condition appearing during a specified point in time or over a period of time.
The primary value of incidence rates is in studies of disease etiology, by comparing how the rates vary among different subgroups or with different exposures

Question 11

what is prevalence? why is it important?

Answer 11

the number of cases (both newly diagnosed and previously diagnosed in current survivors) within a given population in a defined time period. It reflects the penetration of a particular disease or event within a population and can be used to evaluate the impact that treatments are having on a particular disease.
*Prevalence data provide an indication of the extent of a health problem**

Question 12

what is morbidity? why is it important?

Answer 12

the presence of disease in a population;
allow researchers to compare disease cases and deaths to the unit size of population

Question 13

what is mortality? why is it important?

Answer 13

the occurrence of death in a population;
allow researchers to compare disease cases and deaths to the unit size of population

Question 14

what is passive immunity?

Answer 14

refers to short-term resistance that is acquired either naturally or artificially. Newborns, through maternal antibody transfer, have natural passive immunity that lasts up to 1 year for certain diseases

Question 15

what is active immunity?

Answer 15

is long-term and sometimes offers lifelong resistance that is acquired either naturally or artificially

Question 16

difference between naturally & artificially acquired active immunity

Answer 16

natural acquired immunity –> comes through host infection. That is, a person who contracts a disease often develops long-lasting antibodies that provide immunity against future exposures
artificially acquired immunity –> attained through vaccine inoculation. (ex. vaccines for polio, diptheria, smallpox, etc)

Question 17

what is cross immunity?

Answer 17

refers to a situation in which a person’s immunity to one agent provides immunity to a related agent as well. The immunity can be either passive or active.

Question 18

what is herd immunity?

Answer 18

describes the immunity level that is present in a population group. A population with low herd immunity is one with few immune members; consequently, it is more susceptible to a particular disease

Question 19

what are applications of the herd immunity concept?

Answer 19

Mandatory preschool immunizations and required travel vaccinations

Question 20

Epidemiological mitigation of infectious disease – what are the steps and goals?

Answer 20

1. Susceptibility: pre-exposure when vulnerable or at risk; pre-exposure
2. infection: initial transmission of disease from one person to another (this is where mode of transmission becomes important)
3. incubation / latent period: the number of days between when you’re infected with something and when you might see symptoms (Health care professionals and government officials use this number to decide how long people need to stay away from others during an outbreak)
4. Infectious period: Varies for each disease but often happens a few days before symptoms appear until after fever/major symptoms subside

Question 21

what is a relative risk ratio?

Answer 21

statistically compares the disease occurrence in the population at risk with the occurrence of the same disease in people without that risk factor

Question 22

DALY – disability adjusted life years – what is it and why is it important?

Answer 22

a metric that can be used to measure the Global Burden of Disease; The higher the number the greater the burden
calculated as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences

Question 23

SDGs (sustainable development goals)

Answer 23

They recognize that ending poverty and other deprivations must go hand-in-hand with strategies that improve health and education, reduce inequality, and spur economic growth – all while tackling climate change and working to preserve our oceans and forests

Question 24

name a few STGs

Answer 24

no poverty, zero hunger, good health & well-being, quality education, gender equality, clean water & sanitation, affordable & clean energy, decent work & economic growth

Question 25

what is a communicable / infectious disease?

Answer 25

an illness spread by coming in contact with an infected someone or something: Bacteria,viruses, and parasites are the most common organisms causing communicable disease. These illnesses can be passed from person (or animal) to person through direct contact with body fluids, ingesting contaminated food or water, breathing contaminated air, or by the bite of an infected animal