Diseases — Common Communicable and Non-Communicable Diseases

Overview

Diseases form a critical component of Environmental Studies for KTET Category I, connecting health education with everyday life experiences of primary-level learners. This topic bridges science concepts with practical awareness about personal hygiene, community health, and disease prevention—making it highly relevant for classroom teaching.

For KTET, expect questions testing your knowledge of disease classification, transmission modes, causative agents, symptoms, and prevention methods. The exam frequently asks about diseases common in Kerala's tropical climate (dengue, malaria, leptospirosis) alongside nationally relevant conditions. Understanding how to teach young children about diseases using age-appropriate methods is equally important, as pedagogy questions often accompany content questions.

Mastering this topic requires memorising key facts about specific diseases while understanding broader concepts of how diseases spread and how communities can prevent them through collective action.

Key Concepts

• **Communicable diseases** spread from one person to another through direct contact, air, water, food, or vectors (insects/animals). Also called infectious or contagious diseases.

• **Non-communicable diseases (NCDs)** do not spread from person to person. They result from genetic factors, lifestyle choices, or environmental conditions. Also called chronic diseases.

• **Pathogens** are disease-causing microorganisms—bacteria, viruses, fungi, protozoa, and worms. Each pathogen type responds to different treatments.

• **Vectors** are organisms that transmit pathogens without getting sick themselves. Mosquitoes, houseflies, rats, and dogs are common vectors in the Indian context.

• **Incubation period** is the time between infection and appearance of symptoms. Different for each disease and important for understanding disease spread.

• **Immunity** is the body's ability to resist infection. Can be natural (after recovering from disease) or artificial (through vaccination).

• **Endemic diseases** are constantly present in a region. Malaria in parts of Kerala is endemic. **Epidemic** refers to sudden widespread outbreak in a community.

Formulas / Key Facts

| Disease | Type | Caused By | Spread Through | Key Symptoms | Prevention | |---------|------|-----------|----------------|--------------|------------| | **Malaria** | Communicable | Plasmodium (protozoa) | Female Anopheles mosquito | High fever with chills, sweating, headache | Mosquito nets, repellents, no stagnant water | | **Dengue** | Communicable | Dengue virus | Aedes aegypti mosquito | High fever, severe joint/muscle pain, rash | Eliminate breeding sites, wear full-sleeved clothes | | **Typhoid** | Communicable | Salmonella typhi (bacteria) | Contaminated water/food | Prolonged fever, weakness, stomach pain | Safe drinking water, proper sanitation, Typhoid vaccine | | **Cholera** | Communicable | Vibrio cholerae (bacteria) | Contaminated water/food | Severe watery diarrhoea, dehydration | Clean water, ORS for treatment, hygiene | | **Tuberculosis (TB)** | Communicable | Mycobacterium tuberculosis | Airborne droplets | Persistent cough, weight loss, night sweats | BCG vaccine, covering mouth while coughing | | **COVID-19** | Communicable | SARS-CoV-2 virus | Respiratory droplets, aerosols | Fever, cough, breathing difficulty | Masks, hand washing, vaccination | | **Leptospirosis** | Communicable | Leptospira bacteria | Contact with infected animal urine in water | Fever, muscle pain, jaundice | Avoid wading in floodwater, protective footwear | | **Diabetes** | Non-communicable | Insulin deficiency/resistance | Not spread—lifestyle/genetic | Frequent urination, thirst, fatigue | Healthy diet, exercise, weight control | | **Hypertension** | Non-communicable | Multiple factors | Not spread—lifestyle/genetic | Often no symptoms (silent killer) | Reduce salt, exercise, stress management | | **Cancer** | Non-communicable | Abnormal cell growth | Not spread—genetic/environmental | Varies by type | Avoid tobacco, healthy lifestyle, screening | | **Asthma** | Non-communicable | Airway inflammation | Not spread—allergic/environmental | Wheezing, breathlessness, chest tightness | Avoid triggers, use inhalers |