Chapter 3: Health: The Ultimate Treasure

When the common cold virus enters your body, your immune system detects it as a foreign pathogen and activates defense mechanisms. You experience symptoms like a runny nose, sore throat, sneezing, and mild fever — these are actually signs that your body is fighting the infection. The fever helps slow down the virus, while mucus traps and expels it. After a few days, your immune system usually wins and you recover.

Smallpox and polio have been controlled or nearly eradicated through mass vaccination programmes, which trained people's immune systems to fight these diseases before infection. In contrast, diabetes and heart disease are non-communicable diseases linked to modern lifestyle choices such as eating processed food, lack of exercise, obesity, and stress. As living standards change, more people adopt unhealthy habits, making these lifestyle diseases more prevalent. Vaccines cannot prevent lifestyle diseases, so awareness and healthy habits are the only solution.

Yes, climate change can contribute to the rise of new or re-emerging diseases. Rising temperatures and changing rainfall patterns create favourable conditions for disease-carrying vectors like mosquitoes to spread to new regions, increasing diseases like malaria and dengue. Extreme weather events can contaminate water supplies, leading to waterborne diseases. Additionally, melting permafrost could release ancient pathogens that humans have no immunity against, potentially causing new outbreaks.

When we are stressed or worried, our body releases stress hormones like cortisol, which can weaken the immune system over time, making us more vulnerable to infections. Chronic stress can lead to headaches, disturbed sleep, loss of appetite, and high blood pressure. Poor mental health and emotional distress are closely linked to physical health problems like digestive issues and heart disease. This shows that mental and physical health are deeply connected, as the WHO definition of health also includes mental well-being.

Some groups are more vulnerable during disease outbreaks due to factors like weaker immunity (elderly, infants, or those with chronic illnesses), poor nutrition, lack of access to clean water and sanitation, and crowded living conditions. People in poverty may not have access to healthcare, vaccines, or proper hygiene facilities, making them more susceptible. Social factors like lack of education about hygiene and prevention also play a role. This is why community health campaigns targeting vulnerable groups are very important.

The boy's health problems were caused by a combination of loneliness, excessive screen time, and social isolation in his new environment. His habit of spending too much time on his phone to cope with loneliness led to headaches, weight loss, and poor sleep — showing how unhealthy habits can harm physical health. His surroundings (new city, no friends, busy parents) affected his mental and social well-being, which in turn impacted his physical health. This reflects the WHO definition that health includes physical, mental, AND social well-being.

Good habits: Maintaining personal hygiene, eating a balanced diet, exercising regularly, meditating daily, sleeping on time, drinking enough water, and spending time outdoors. Bad habits: Spending too much time on screens, eating junk food daily, sleeping very late, skipping meals (especially breakfast), avoiding physical activity, and consuming tobacco or alcohol. Students should reflect on which good habits they already follow and set a goal to adopt more. Reducing bad habits and replacing them with healthy ones is the key to long-term well-being.

I would prefer to play in the clean, well-maintained playground (Fig. 3.3a) because it provides a safe, hygienic environment that supports good health. A clean playground reduces the risk of infections, injuries from broken equipment, and exposure to pollutants. The polluted, dirty playground (Fig. 3.3b) could expose children to harmful pathogens, contaminated water, and air pollution, increasing the risk of communicable diseases. Our surroundings have a direct impact on our physical and mental health.

Airborne diseases (e.g., tuberculosis, flu, COVID-19): Wear masks, cover mouth while coughing/sneezing, avoid crowded places, get vaccinated. Waterborne/foodborne diseases (e.g., typhoid, cholera, hepatitis A): Drink clean boiled water, eat properly cooked food, wash hands before eating, maintain sanitation. Vector-borne diseases (e.g., malaria, dengue): Use mosquito nets and repellents, eliminate stagnant water near homes, wear full-sleeved clothing. General precautions include maintaining personal hygiene, staying home when sick, and getting regular vaccinations.

Three common lifestyle diseases in most Indian neighbourhoods: Diabetes, hypertension (high blood pressure), and obesity. Diabetes can be managed by reducing sugar intake, exercising regularly, and maintaining a healthy weight. Hypertension can be prevented by reducing salt and fat in diet, managing stress, avoiding smoking and alcohol, and exercising. Obesity can be controlled by eating balanced meals, avoiding junk food, staying physically active, and limiting screen time. Early diagnosis and regular health check-ups are also important for managing these diseases.

The Odisha community sanitation campaign shows that simple public health measures like building and using toilets can significantly reduce the spread of communicable diseases like diarrhoea. When open defecation is stopped, pathogens from human excreta cannot contaminate water sources or soil, breaking the chain of disease transmission. This proves that community participation in hygiene campaigns directly improves child health and reduces infections. Similar campaigns in India include the Swachh Bharat Abhiyan, which promotes cleanliness and sanitation across the country.

How antibiotic resistance develops: When antibiotics are taken unnecessarily or in incomplete doses, most bacteria are killed but a few with natural resistance survive. These resistant bacteria multiply and pass on their resistance to other bacteria, making the antibiotic ineffective over time. Antibiotics also kill the good bacteria in our body that protect us from infection, allowing resistant strains to dominate. Resistant bacteria can spread through animal food products, contaminated soil/crops, hospitals, and direct human contact. Precautions to reduce antibiotic resistance: Only take antibiotics when prescribed by a doctor; always complete the full course; never share antibiotics; avoid giving antibiotics to livestock unnecessarily; maintain hygiene to prevent infections in the first place.

Communicable diseases (caused by pathogens and can spread from person to person): Tuberculosis, Dengue, Malaria, Cholera, Typhoid, Chickenpox, COVID-19, Influenza (flu), Measles. Non-communicable diseases (not caused by pathogens, linked to lifestyle/environment): Diabetes, Cancer, Asthma, Heart disease, Obesity. The key difference is that communicable diseases are caused by pathogens and can be transmitted, while non-communicable diseases are related to lifestyle, genetic, or environmental factors and do not spread between people.

✔ Correct Answer: (b) (ii) and (iii)

Why (b) is correct: Asthma (ii) and Diabetes (iii) are non-communicable diseases — they are not caused by pathogens and cannot spread from one person to another. Asthma is linked to environmental triggers and genetics, while diabetes is related to hormonal imbalances and lifestyle factors.

Why other options are wrong:

• (a) Typhoid (i) is a communicable disease caused by Salmonella typhi bacteria, spread through contaminated water and food.
• (c) Typhoid (i) is communicable, so this option is incorrect.
• (d) Measles (iv) is a communicable disease caused by a virus and spreads through air, so this option is incorrect.

(i) Immediate actions by the school: The school should inform parents about the outbreak and advise sick students to stay home. Classrooms should be regularly sanitised, especially surfaces like desks and door handles. The school can arrange for hand sanitisers, encourage mask-wearing, and improve ventilation. If the outbreak is severe, authorities may consider temporary closure and inform health officials.

(ii) Responding considerately to a sick classmate: You can gently suggest to your classmate that they inform the teacher and consider going to the sick room or going home to rest. Explain that staying in school while sick can spread the illness to others, including their friends. Be kind and empathetic — say something like, 'You don't look well, maybe you should rest — it'll help you recover faster.' Avoid being rude or making them feel embarrassed.

(iii) Protecting yourself and others: Wash your hands frequently with soap and water, especially before eating and after touching shared surfaces. Avoid touching your face, mouth, and nose. If possible, wear a mask in crowded areas. Stay home if you develop symptoms, drink plenty of water, and get adequate rest to keep your immune system strong.

(i) Precautions before, during, and after the trip: Before: Consult a doctor about anti-malarial medication, get any recommended vaccinations, and pack mosquito repellents and nets. During: Use mosquito repellent on exposed skin, sleep under a mosquito net, wear full-sleeved clothing especially at dawn and dusk when mosquitoes are most active, and avoid areas with stagnant water. After: Monitor for symptoms like fever, chills, and body ache for several weeks after returning; visit a doctor immediately if any symptoms appear.

(ii) Explaining mosquito nets and repellents to your sibling: You could say: 'Malaria is spread by mosquito bites — the mosquito carries a tiny parasite called Plasmodium that enters your blood when it bites you. A mosquito net creates a barrier so mosquitoes cannot reach you while you sleep, and repellent keeps them away from your skin. Using these is like wearing a shield that protects us from getting sick.'

(iii) Consequences of ignoring health advisories: If travellers ignore health advisories, they risk contracting diseases like malaria, which can cause high fever, organ failure, and even death if untreated. They could also unknowingly carry the pathogen back to their home city and spread the disease to others who have no immunity to it. Ignoring advisories puts both the individual and the broader community at serious health risk.

(i) Talking to your uncle about smoking: You could say: 'Uncle, I really care about your health and I am worried about you. Smoking causes serious diseases like lung cancer, heart disease, and breathing problems. True friends would support healthy choices — fitting in is not worth risking your life. There are better ways to bond with friends, like sports or other activities.' Be gentle, respectful, and show that your concern comes from love.

(ii) If a friend offers you a cigarette: Politely but firmly say 'No, thank you — I don't smoke and I don't want to.' You do not need to explain yourself further. True friends will respect your decision. Remember that peer pressure is very common, but your health is more important than fitting in. You could also redirect the conversation or suggest doing something else together.

(iii) How schools can help prevent harmful habits: Schools can conduct health awareness sessions and invite doctors to speak about the dangers of smoking, alcohol, and drugs. Including topics on peer pressure, self-confidence, and saying 'No' in the curriculum helps students make informed decisions. Schools can create a positive environment with sports, arts, and clubs so students find healthier ways to socialise and belong. Strict no-smoking policies on campus also set a clear example.

Vinita can ask Saniya these questions to challenge her claim: 1. 'Do you know that antibiotics only work against bacterial infections — what happens when we get a viral infection like the flu or COVID-19? Will antibiotics help then?' 2. 'Have you heard of antibiotic resistance? If we use antibiotics for every small infection, bacteria can become resistant and the antibiotic will stop working — what will we do then?' 3. 'Did you know antibiotics also kill the good bacteria in our body that protect us? Could that be harmful?' 4. 'Should we take antibiotics without a doctor's prescription?' These questions guide Saniya to realise that antibiotics are not a universal cure and must be used responsibly.

(i) Three months with highest dengue cases: Based on typical dengue patterns in India, cases are highest in September, October, and August — the post-monsoon period when mosquito breeding is at its peak due to stagnant water.

(ii) Month(s) with lowest cases: Cases are typically lowest in January and February (winter months), when mosquito activity is minimal due to lower temperatures.

(iii) Environmental factors during peak months: The monsoon season (July–September) brings heavy rainfall that creates pools of stagnant water — ideal breeding grounds for the Aedes mosquito that transmits dengue. Warm and humid conditions after the rains further accelerate mosquito reproduction. Increased outdoor activity and open water storage also contribute to more mosquito-human contact.

(iv) Preventive steps before peak season:

• Eliminate stagnant water around homes (empty flower pots, tyres, coolers regularly).
• Use mosquito nets, window screens, and repellents.
• Government should conduct fogging and larvicide spraying before monsoon.
• Distribute information through community campaigns about dengue prevention.
• Encourage wearing full-sleeved clothing during early morning and evening hours.

Key messages for communicable disease prevention:

• 'Wash your hands — stop germs in their tracks!'
• 'Get vaccinated — protect yourself and your community.'
• 'Stay home when sick — don't spread what you've got.'
• 'Drink clean water and eat hygienic food to prevent waterborne diseases.'
• 'Use mosquito nets and repellents — beat the bite!'

Key messages for non-communicable disease prevention:

• 'Eat a balanced diet — less sugar, less salt, more fruits and vegetables.'
• 'Move more, sit less — exercise every day for at least 30 minutes.'
• 'Say NO to smoking, tobacco, and alcohol — your future depends on it.'
• 'Manage your stress — practice yoga, meditation, and deep breathing.'
• 'Sleep well, live well — get 8 hours of sleep every night.'

The overall message could be: 'Your health is your greatest treasure — small daily habits make a big difference!'

Antibiotics are medicines that specifically target and kill bacteria by attacking parts of bacterial cells. Viruses are completely different from bacteria — they have a different structure, no cell wall, and they replicate inside human cells, so antibiotics have no effect on them whatsoever. Taking antibiotics for a viral infection is not only useless but also harmful — it kills the good bacteria in your body that protect you from other infections, and it contributes to antibiotic resistance, making antibiotics less effective in the future. Viral infections like cold, cough, and flu are best managed with rest, fluids, and allowing the immune system to fight the virus naturally.

The diseases that can spread through drinking water contaminated by infected excreta (faecal-oral route) are: Hepatitis A, Poliomyelitis, and Cholera. These pathogens are shed in the faeces of infected people and enter water sources through poor sanitation, spreading to healthy people who consume contaminated water or food. Tuberculosis spreads through the air (droplets from coughing/sneezing) and Chickenpox spreads through direct contact and air — neither spreads through contaminated water. This is why proper sanitation, clean drinking water, and hygiene are critical in preventing these waterborne diseases.

When the body encounters a pathogen for the first time, the immune system takes time to recognise it, produce antibodies, and fight it — this is called the primary immune response and it is relatively slow and weak. However, during this first exposure, the immune system creates special memory cells (memory B and T cells) that 'remember' the specific pathogen. When the same pathogen enters the body again, these memory cells quickly recognise it and launch a faster, stronger secondary immune response, producing more antibodies in a much shorter time. This is the principle behind how vaccines work — they introduce a harmless version of the pathogen to train the immune system and create memory cells without causing the actual disease.