Concept Of Disease Control
Concept Of Disease Control
What Is Disease Control?
Disease Control is the term used to describe operation or activities with the aims;
- To reduce incidences of diseases.
- To reduce duration of diseases.
- To reduce chances of transmission of diseases from one person to another.
- To reduce negative effects of disease which include both the physical & psychological complications.
- To reduce financial burden to the community in case of any disability.
The disease control is dealt while studying Epidemiological Triangle. The agent, host & environmental factors form three corners of epidemiological triangle.
These three factors are required for a disease to occur & in the absence of any one of these factors, no disease can occur. These factors are present in our environment but in isolation form. When the interaction is built among these factors, man undergoes disease process & moves to Pathogenesis Phase.
Note: – In all cases, disease control doesn’t involve eradicating of the agent of the disease completely rather than permitting it to persist in a community at a level (if possible) where it can’t cause health problems.
Disease control may be of two types;
- Disease Elimination (Removal from a region)
- Disease Eradication (Removal from the world)
1. Disease Elimination (Removal From A Region)
Disease Elimination describes the removal of a particular disease from a large geographical era but not from the whole world. It is a regional process. It involves interruption of disease transmission. Examples include removal of measles from Lahore etc.
2. Disease Eradication (Removal From The World)
Disease Eradication describes the removal of a particular disease form the whole of the world not merely from a certain region or a large geographical area. It is an absolute term which means “tear out by roots”.
The only example of the disease eradication is Small Pox. The world has been declared free from small pox virus by WHO (World Health Organization).
Natural History Of The Disease
“The way in which a disease evolves in the absence of any intervention is the Natural History of the Disease”.
The disease results from the complex interaction of three things i-e man (host), agent (cause of disease) & the environment.
Natural history of the disease involves;
- Pre-pathogenesis phase (Before man is involved)
- Pathogenesis phase (After man is involved)
A. Pre-pathogenesis Phase
Pre-pathogenesis phase is the time period before the onset of disease. As is clear from background knowledge, three factors are required for a disease to occur which are;
Note: – If any one of these three factors is missing, disease fails to occur.During pre-pathogenesis phase, disease is not there i-e man is not involved but risk of disease is there. For examples, many diseases are there in our society and we are not the victim of these disease. So we are in the pre-pathogenesis phase of such diseases.These three factors are present in our environment but in isolation form. When the interaction is built among these factors, man undergoes disease process & moves to Pathogenesis Phase.
B. Pathogenesis Phase
Pathogenesis phase starts when man comes in contact with an agent of disease i-e with the entry of disease agent into the susceptible human host.
Note: – Once the agent comes into interaction with host & even the symptoms of the disease don’t appear (incubation period), the man is in pathogenesis phase.
“Incubation Period is the time period b/w the entry of disease agent into the host and appearance of signs & symptoms of disease.”
A person in incubation period of pathogenesis phase may be apparently healthy but some processes (physiological as well as pathological) are going on in the body which is regarded as sub-clinical. As the incubation period passes, signs and symptoms of the disease appear.
The signs and symptoms are slight in the beginning and progressively become severe and diagnosis becomes easier. The results of disease may be;
- Complete recovery
Let’s have a brief discussion about Epidemiological/Ecological/Etiological Triad.
The agent, host & environmental factors form three corners of epidemiological triangle.
What Is An Agent?
“The agent is an organism or force, living or non-living, tangible or non-tangible, presence or relative deficiency of which can trigger a disease process to occur.”
A single agent may cause different diseases and a disease may have many agents i-e a single cause may have different effects or a single effect may be cause by different causes. This results into Multi-factorial Causation and forms Web of Causation.
Classification Of Agent
Agent may be of following types;
- Biological agent (Insects)
- Nutrient agent (Vitamins, Minerals)
- Physical agent (Hot, Cold, Air pressure)
- Mechanical agent (Friction)
- Chemical agent (Acids, Metals)
- Social agent (Smoking, Poverty)
What Is Host?
Host is mainly the human who is considered as soil and the disease agent is considered as a seed. Host factors play important role when an interaction take place b/w agent and host.
Classification Of Host Factors
Host factors are classified as
- Demographic characters (Age, Gender)
- Biological characters (Blood group, Enzymes)
- Social & Economic characters (Socio-economic status, Education)
- Lifestyle factors (Habits, Nutrition)
What Is Environment?
Environment is the place where we live. Certain environmental factors play important role in disease.
The environment is divided into;
- Internal environment (The environment inside our body)
- External environment (the environment outside our body)
External environment is further divided into three types;
- Physical environment (Air, Water, Housing, Radiations, Noise)
- Biological environment (Viruses, Bacteria, Parasites, Plants)
- Social environment (Religion, Caste, Laws, Social systems)
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