Concept of one to one relationship between agent and disease is explained by?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Microbiology

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Explanation

The Germ Theory of Disease is defined by the principle of a one-to-one relationship between a specific pathogenic microorganism (agent) and a specific disease.
This model was foundational in microbiology and infectious disease, proposing that for every infectious disease, there is a corresponding specific germ.
A classic example is the bacterium Vibrio cholerae being the single agent responsible for causing cholera.
This concept is in direct contrast to multifactorial models, which propose that multiple factors contribute to disease development.

Option B: This theory posits that diseases, especially chronic ones, are caused by the interplay of multiple factors (e.g., genetics, lifestyle, environment), which is the opposite of a one-to-one relationship.
Option C: The Epidemiological Triad involves the interaction of three components: the agent, the host, and the environment. This is more complex than a simple one-to-one relationship as it considers host susceptibility and environmental conditions.
Option D: The Web of Causation is the most complex model, illustrating that chronic diseases are caused by a complex, interconnected network of numerous factors. It directly contradicts the simplicity of a one-to-one relationship.

Clinical Relevance

Nursing practice connection: Knowing Theories of Disease Causation helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the Germ Theory is fundamental to all infection control practices in nursing, such as hand hygiene, sterilization of equipment, and use of personal protective equipment (PPE). These actions are designed to break the one-to-one link between the pathogenic agent and the host.
This concept justifies the use of antibiotics to target a specific bacterium (agent) to cure a specific infection (disease).
What if? If a patient presents with a condition like hypertension, a nurse cannot rely on the Germ Theory. Instead, they must use a multifactorial approach, assessing various risk factors like diet (high sodium), lack of exercise, stress, and family history to plan care.

How to Approach the Question

First, identify the key phrase in the question: "one to one relationship between agent and disease".
This is a factual recall question that asks you to match a specific definition to its corresponding epidemiological theory.
Recall the definitions of the different models of disease causation.
The Germ Theory is the classic model that proposes a single germ causes a single disease.
The other options (Multifactorial, Triad, Web of Causation) all describe more complex interactions involving multiple factors or components.
Therefore, match the phrase "one to one relationship" directly to the "Germ theory of disease".

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 24-26