Lec #3 (Wk 2): Primordial & Primary Prevention

Question 1

What is the clinical course of a disease?

Answer 1

Without the human intervention (i.e medicine), it is divided into 4 phases.

1- Etiological phase; made up of social & environmental determinants, risk & protective factors.

2- Pre-clinical phase; biological onset of disease but asymptomatic at this phase.

3- Clinical phase; where symptoms appear, diagnosis, & therapy happens.

4- Post clinical phase; longer-term outcomes.

Question 2

The first phase of the clinical course of a disease is the etiological phase. What is that?

Answer 2

It is the stimulus that triggers the occurrence of a disease. It is mainly divided into 2 categories:
1- Social & environmental determinants;
- Nutrition.
- Climate.
- Crowding.
- Stress.

Risk & Protective Factor:
Risk factors makes the disease more likely to start, while the protective factor makes the disease less likely to start. They are related to the host & mainly include:
- Genetics.
- Immunological state.
- Age.
- Personal behavior.
Once the disease is triggered you move on to the preclinical phase where you have some impairements.

Question 3

What is the preclinical phase of the clinical course?

Answer 3

is mainly the biological onset of the disease and it is
characterised by having some impairments that do not have clinical signs
and symptoms. in the case of diabetes, the impairment that takes place in the
preclinical phase is the increase in insulin resistance since the tissues
become more resistant to insulin. the pancreas has to work harder
to produce more insulin and eventually, it will become exhausted and
dysfunctional.

Question 4

Which clinical course phase includes the epidemiological triad?

Answer 4

Pre-clinical phase.

Question 5

What is the epidemiological triad?

Answer 5

This is a triangle which are of 2 types:
- Analytical
- Descriptive
Our focus is analytical epidemiological triad.
This is composed of a triangle with; host, environment, and agent.
A mechanism for the agent to get to the host is needed so that the disease can
start. This mechanism is called the vector.
If you are missing 1 of the 3 elements; environment, host, and agent. The disease will not take place. Only when the 3 elements get together, the disease can occur.

**VIP POINT!!! IN THE PRECLINICAL PHASE, THESE 3 ELEMENTS INTERACT IN A WAY THAT DOESN’T CAUSE DISEASE.

Question 6

What does a host mean in the epidemiological triad?

Answer 6

Host is the organism or the human being who will get the disease. Host is affected by a set of risk & protective factors.

Question 7

What does an agent mean in the epidemiological triad?

Answer 7

An agent is anything that can cause damage to the host & these agents can be divided into 4 groups:
- Chemical agents.
- Biological agents.
- Physical agents.
- Psychological experience.

Question 8

What does the environment mean in the epidemiological triad?

Answer 8

Brings host & the agent together meaning that it facilitates the agent & host coming together and includes social + environmental determinants.

Question 9

What does the vector mean in the epidemiological triad?

Answer 9

The vector carries the agent to the host. E.g: The vector could be the water supply system for the cholera bacterium. Another e.g is the toxins in the smoke of the cigarettes that cause CHD.

Question 10

At what phase do the 3 elements of the epidemiological triad interact to cause symptoms of the disease?

Answer 10

Clinical phase.

The impairment in the preclinical phase becomes a disability in the clinical phase.

Question 11

What is the post clinical phase?

Answer 11

After the clinical phase, there will be an outcome. These outcomes could be:
- Recovery.
- Chronic state.
- Incapacity.
- Death.
- One of the outcomes is being handicapped.

The impairment in the preclinical phase becomes a disability in the clinical phase and in the post-clinical phase COULD become handicapped.

Question 12

What is a sufficient cause, necessary cause, and component cause?

Answer 12

Think of a pizza, each slice is called a component cause and this represents the presence of risk factor or absence of a protective factor. One of the slices is called a necessary cause meaning that it MUST be present for the disease to occur (it is usually the agent), the absence of this necessary cause means disease can NEVER EVER happen. The entire pizza is called a sufficient cause. Every risk factor contributes to the disease but you need to reach a certain threshold which is the sufficient cause before the disease happens.

NOTICE!!
The necessary cause itself is not a sufficient cause (But in some cases it can which we will show an example):

E.g #1:
If we only had vibrio cholera present, then the disease cannot happen since it needs malnutrition and poverty.

E.g #2:
Ebola virus is a necessary cause of the disease AND a sufficient cause. Thus, if the necessary cause is a very virulent factor that causes the disease, you may not need other component causes & this necessary cause becomes a sufficient cause.

Question 13

How to identify the necessary cause?

Answer 13

If we look at a disease, we should see which component cause is present in every person infected.
BTW the component cause for every person will be different but when we see 1 common thing in all these people with the same disease, we know this is the necessary cause.

Question 14

What are the lines of prevention?

Answer 14

1- Primordial prevention.
2- Primary prevention.
3- Secondary prevention.
4- Tertiary prevention.

Question 15

What is primordial prevention?

Answer 15

Here, you are preventing the risk factor from happening which begins with changing the societal structures & environmental conditions. Primordial prevention targets the GENERAL POPULATION.

Question 16

What is primary prevention?

Answer 16

It is the action taken prior to the onset of the disease (before the preclinical phase starts) meaning that the risk factor is still there, you are not preventing the risk factor anymore (primordial prevention). Primary prevention targets susceptible population (they don’t have the problem but have some of the component causes) and tends to target the component causes.

Question 17

Provide example of primordial and primary prevention.

Answer 17

Smoking which is a risk factor for lung cancer.

Primordial prevention –> when the government puts taxes on cigarette companies which makes cigarettes unaffordable for anyone (here preventing the risk factor from ALL people).

Primary prevention –> Putting a program to advice people to stop smoking; we try to stop the person from coming in contact w the risk factor although it still exists in the environment. So like banning it in the malls, hospitals, airport, and etc.

Question 18

Is it easier to go for primordial or primary prevention?

Answer 18

Primary prevention is easier than primordial prevention.
Because primordial prevention needs collaboration between the government and people.
E.g:
56-60% of diabetes in Qatar is bc of obesity.
primordial prevention –> banning fast food restaurant & coffee shops in qatar.

Primary prevention –> Screen people who are at high risk then we do primary prevention to prevent THEM from reaching the sufficient cause.

Question 19

What are the ways to achieve primary prevention?

Answer 19

1- Health promotion;
Displaying posters & pamphlets educating people about things they should avoid.
- Health education; educating people about how to wash their hands or the importance of vaccines.
- Environmental modifications; like removing garbage from houses and sources of water contamination.
- Nutritional intervention; providing appropriate nutrition to children.
- Lifestyle & behavioral changes.

2- Specific protection;
Protecting individuals against a SPECIFIC DISEASE.
- Immunization.
- Chemoprophylaxis; drug to prevent a specific disease.
- Using supplements; e.g vit A to prevent night blindness.
- Protection against occupational hazard like earplugs to prevent deafness in those working in Hamad international airport.
- Control of environmental hazards.

Question 20

What does mass & targeted strategy mean?

Answer 20

They represent 2 strategies of delivering the primary prevention.
Mass strategy –> directed to the individuals at higher risk.
Targeted strategy –> aims to Bring preventative care to individuals at higher risk.

Question 21

What are the routes of transmission for polio?

Answer 21

1- Oral-oral infection.
2- Faeco-oral infection.
3- Food-borne infection.
4- Hand to mouth infection.

**polio virus has the ability to survive in cold env.

Question 22

What are the types of polio vaccinations available?

Answer 22

There are 2 Polio vaccinations;
- IPV (Salk)
- OPV (Sabin)
(Search up ops vs ipv then click on the pic with insights IAS).

Question 23

How many doses of OPV are given?

Answer 23

3 doses makes up over 95% immune against polio. Can shed in stool for up to 6 weeks following vaccination.

Question 24

Who is at risk of getting Vaccine-associated paralytic poliomyelitis (VAPP) which is the adverse event following exposure to OPV?

Answer 24

1- persons >18 y/old.
2- people with immunodeficiency.