Notes-NCERT-Class-8-Science-Curiosity-Chapter-3-Health: The Ultimate Treasure-CBSE

Some common communicable diseases affecting humans and preventive measures :

How Antibiotic Resistance Spreads :

(i) Through Humans:

• Taking antibiotics when not needed makes bacteria in the body resistant.
• Sick patients with resistant bacteria may spread them in hospitals (to other patients, healthcare workers, or through dirty surfaces).
• When these patients go home, they spread resistant bacteria in the community.

(ii) Through Animals and Plants:

• Antibiotics used in animals make bacteria resistant inside them.
• Resistant bacteria enter soil through animal waste and then reach crops.
• People get exposed by eating these crops or animal food products.

(iii) Main Problem:

• Antibiotics kill normal bacteria but leave resistant ones alive.
• These resistant bacteria grow, spread, and can even pass their resistance to other bacteria.

(iv) Solution:

• Use antibiotics only when prescribed.
• Take the right dose, for the right duration.
• Avoid misuse to stop the rise of resistant bacteria.

How Bacteria Become Antibiotic-Resistant :

• Antibiotics kill the harmful bacteria causing illness.
• They also kill some “good bacteria” that protect us.
• A few bacteria may naturally survive because they are resistant.
• When the normal bacteria die, these resistant ones multiply and take over.
• Resistant bacteria can also pass their resistance to other bacteria.

As a result, infections that were once easy to treat become harder, last longer, and may cause serious complications or even death.

Glossary of Key Terms :

• Acquired Immunity: Protection developed by the immune system after exposure to a pathogen or a vaccine.
• Air Quality Index (AQI): A scale used to report air quality, indicating how clean or polluted the air is.
• Antibiotic Resistance: A phenomenon where bacteria develop the ability to survive and multiply despite treatment with antibiotics, making infections harder to treat.
• Antibiotics: Medicines that specifically kill or inhibit the growth of bacteria, used to treat bacterial infections.
• Asthma: A chronic non-communicable disease affecting the airways of the lungs, often linked to environmental factors and genetics.
• Ayurveda: A traditional Indian system of medicine that emphasizes balance of body, mind, and surroundings for health, including practices like dinacharya (daily routine) and ritucharya (seasonal routine).
• Communicable Diseases: Diseases caused by pathogens that can spread from one person to another (e.g., flu, chickenpox, typhoid).
• COVID-19: A communicable respiratory illness caused by a virus, mentioned as an example of a recent pandemic.
• Chronic Diseases: Diseases that persist for a long time, typically more than 3 months, often referring to non-communicable diseases like diabetes or cancer.
• Deficiency Diseases: Non-communicable diseases caused by a lack of specific nutrients in the diet (e.g., scurvy, anemia, goitre).
• Dengue Fever: A communicable disease caused by a virus and transmitted by mosquitoes (a vector).
• Diabetes: A non-communicable disease characterized by high blood sugar levels, often linked to hormonal imbalances, unhealthy eating habits, and lack of physical activity.
• Dinacharya: A concept in Ayurveda referring to a recommended daily routine for maintaining health and balance.
• Disease: A condition that affects the normal working of the body or mind, occurring when one or more organs or organ systems stop functioning properly.
• Dry Eye Disease: A condition where the eyes do not produce enough tears or tears evaporate too quickly, often linked to excessive screen watching.
• FIT INDIA MOVEMENT: A national initiative in India to encourage people to stay healthy and fit by including physical activities and sports in their daily lives.
• Health: As defined by WHO, a "state of complete physical, mental, and social well-being, and not merely the absence of disease."
• Hepatitis A: A communicable disease affecting the liver, often spread through contaminated food and water.
• Immune System: The body's special system that helps fight against diseases and protect against harmful pathogens.
• Immunity: The natural ability of the body to fight diseases.
• Influenza (Flu): A common communicable viral infection of the respiratory tract.
• Lifestyle: The way a person lives, including their habits, behaviors, and choices that affect their health.
• Malaria: A communicable disease caused by a protozoan parasite and transmitted by mosquitoes (a vector).
• Measles: A highly contagious communicable viral disease affecting the skin and respiratory tract.
• Non-communicable Diseases (NCDs): Diseases that are not caused by pathogens and do not spread from one person to another; usually linked to lifestyle, diet, and/or environment (e.g., cancer, diabetes).
• Parasites: Organisms that live in or on another living being (the host) and obtain nutrients at the host's expense (e.g., intestinal worms).
• Pathogens: Disease-causing organisms such as bacteria, viruses, fungi, worms, or protozoa.
• Penicillin: The first antibiotic discovered by Alexander Fleming, effective against bacterial infections.
• Physical Health: The well-being of the body, including its proper functioning and absence of physical ailments.
• Prakriti: A concept in Ayurveda referring to an individual's unique body constitution, influencing dietary and lifestyle recommendations.
• Pranayama: Breathing exercises practiced in yoga, beneficial for mental and physical well-being.
• Protozoa: Single-celled organisms, some of which can be pathogens (e.g., causing malaria).
• Ritucharya: A concept in Ayurveda referring to a seasonal routine recommended for maintaining health and balance throughout the year.
• Sign (of illness): Something that can be seen or measured by others, indicating that a person is unwell (e.g., fever, rash).
• Smallpox: A deadly communicable disease caused by a virus, famously eradicated globally through vaccination.
• Social Well-being: The aspect of health that involves a person's ability to adjust well with peer groups and other members of society and enjoy social life.
• Symptom (of illness): What a person feels when unwell (e.g., pain, tiredness).
• Tetanus: A serious bacterial infection that can be prevented by vaccination.
• Typhoid: A communicable bacterial infection of the intestine, often spread through contaminated food and water.
• Vaccines: Preparations (containing weakened, dead, or harmless parts of pathogens) that train the immune system to recognize and attack harmful germs, providing protection against specific diseases.
• Variolation: A traditional method, practiced in India and elsewhere, of protecting against smallpox by using material from a smallpox sore to induce a mild infection and build immunity.
• Vectors: Organisms, typically insects, that transmit disease-causing pathogens from one host to another (e.g., mosquitoes for malaria and dengue).
• Yoga: An ancient Indian practice involving physical postures, breathing exercises, and meditation, promoting overall well-being.