Question

Discuss how diseases are categorized.

Answer 1

The disease can be categorized on the basis of:

1. Extent of occurrence
2. Infectious nature
3. Type of pathogen
4. Transmitting Agent

1. Extent of occurrence:

1. Endemic diseases – Found in a certain geographical area affect the fewer number of people, E.g. Goitre in sub = Himalayan region.
2. Epidemic diseases – Disease which breaks out and affects a large number of people in a particular geographical region and spreads at the same time. E.g. Influenza.
3. Pandemic disease – Widely distributed on a global scale. E.g. AIDS.
4. Sporadic disease – Occasional occurrence of a disease. E.g. Cholera and malaria.

2. Infectious nature:

A. Infectious diseases are communicable diseases. Caused by external factors pathogenic organisms. E.g. Chickenpox and malaria.

B. Non-Infectious disease:

1. Non-communicable diseases.
2. Caused by internal factors like :
3. Malfunctioning of organs and genetic causes. Hormonal imbalance and immune system defect. E.g. diabetes, coronary heart diseases, obesity, cancer, goitre etc.

3. Types of pathogen:

1. Bacterial diseases
2. Viral diseases
3. Fungal diseases
4. Protozoan diseases

4. Transmitting agent:

1. Airborne diseases: Due to continuous inhalation of contaminated air.
   E.g. Tuberculosis.
2. Waterborne diseases: Microbes present in contaminated water cause various infectious diseases.
   E.g. Cholera, typhoid, etc.
3. Vector-borne diseases: Vector is an agent that acts as an intermediate carrier of the pathogen.
   E.g. Malaria, filaria, chikungunya.