Hello, my dear students! Welcome to today's science lesson. I am so happy to see you all here, ready to learn something new and important. Today, we are going to study Chapter 3 from your Science textbook — "Health: The Ultimate Treasure." Now, isn't that a beautiful title? Health is indeed the greatest wealth we can have, and in this chapter, we will understand what it truly means to be healthy, how diseases spread, and how we can protect ourselves and our loved ones. So, let's begin our journey together!
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## 3.1 Health: Is It More Than Not Falling Sick?
Now, students, let's start with a very important question. What do you think health means? Many of us believe that being healthy simply means not having a fever, not coughing, or not having any pain in the body. But is that all there is to health? Let's think about this carefully.
Look at the news clippings that you might see on notice boards in your school or in newspapers. They tell us about people's health in our country. Some people are suffering from diseases, some are dying due to pollution, and some are living happy and active lives. So, what is it that makes the difference?
Students, health is much more than just not being sick. According to the World Health Organization, which is also called WHO, health is defined as a "state of complete physical, mental, and social well-being, and not merely the absence of disease." This is a very important definition, and I want you to remember it. So, let me say it once more. Health means complete physical well-being, which means our body is working properly; mental well-being, which means our mind is happy and peaceful; and social well-being, which means we have good relationships with family, friends, and society. When all these three aspects are in balance, we can say a person is truly healthy.
Now, let me give you an example. Suppose a student studies very hard for exams but doesn't sleep enough, doesn't play, and doesn't spend time with friends. Even if they don't have any disease, are they truly healthy? No, because their mental health is suffering due to stress, and their social health is suffering due to lack of interaction with others. So, students, being healthy means taking care of our body, mind, and relationships.
A healthy person can generally perform various tasks more efficiently and cope well in different and difficult situations. A healthy person can adjust well with peer groups and other members of society. This is what health is all about.
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### Activity 3.1: Let us read
Now, students, let's look at a real-life example given in your book. There is a story of a Grade 8 student who moved to a new school in another city. Can you imagine how difficult that must be? He had no friends in his new environment, and his parents were very busy with their work. So, he felt lonely and isolated. To cope with this loneliness, he started spending more time on his phone and social media. But do you know what happened? This actually made him feel worse! He stopped trying to make friends, started getting headaches, lost weight, and could not sleep well at night. Finally, a doctor advised him to spend less time on screens and to meet a counsellor. The school counsellor arranged help to support him in making friends and improving his health.
Now, students, think about this. What was the cause of the boy's health problems? The cause was not a virus or bacteria. It was his habits and surroundings. He was lonely, he was spending too much time on his phone, he wasn't sleeping well, and he wasn't trying to connect with others. All these factors affected his physical health, mental health, and social health. This is why his health deteriorated even though he might not have had any specific disease.
So, students, this activity teaches us that our habits and surroundings have a huge impact on our health. Even if we don't have a disease, we can still be unhealthy if we are lonely, stressed, or not taking care of ourselves properly.
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### Our scientific heritage
Now, students, let's talk about something very close to our Indian culture. Our ancestors taught us about health thousands of years ago through Ayurveda. Ayurveda teaches us that true health is a balance of body, mind, and surroundings. Doesn't that sound familiar? It is exactly what the WHO definition says! Our ancient wisdom was far ahead of its time.
In Ayurveda, there is something called dinacharya, which means daily routine, and ritucharya, which means seasonal routine. Following these routines helps maintain balance in our body and mind. For example, waking up early in the morning, eating meals at regular times, and sleeping at a proper time are part of dinacharya. Similarly, eating foods that are suitable for different seasons is part of ritucharya.
Ayurveda also teaches us about prakriti, which means body constitution. Each person has a different body type, and we should eat food that suits our prakriti. Eating fresh, wholesome food is essential for good health. Regular exercise, cleanliness, restful sleep, and a calm mind support overall well-being. This can also be achieved through practices like yoga, meditation, and mindfulness, which have now become popular all over the world. So, students, our scientific heritage has given us wonderful tools for staying healthy, and we should make the most of them.
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## 3.2 How Can We Stay Healthy?
Now, students, let's come to the most practical part of this chapter. How can we stay healthy? What should we do and what should we avoid? Let's list some important points.
For staying healthy, we must eat nutritious food, maintain hygiene, stay in a clean place, exercise regularly, get proper sleep, spend time with family and friends, and have a positive attitude. These are the pillars of good health. Let me explain each one of them in detail.
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### Activity 3.2: Let us list
Now, students, let's do an activity together. In your book, there is a list of good habits and bad habits. Let me go through them with you.
Good habits that your parents, teachers, or elders often encourage you to follow include: keeping yourself clean by maintaining personal hygiene, eating a healthy and balanced diet, exercising regularly, and making time to relax or meditate every day. Now, students, think about how many of these are already a part of your daily routine. Which ones would you like to start following? It is good to reflect on this and make a promise to yourself to adopt at least one new healthy habit.
Now, let's think about habits that are not good for your health. These include: spending too much time on mobile phones or other digital screens, eating fast food and other junk food every day, sleeping very late or not getting enough sleep, and skipping meals, especially breakfast. These habits can harm our health in the long run, and we should try to avoid them.
Students, taking care of our body and mind is important. Healthy habits support a healthy body as well as a healthy mind. So, discuss your findings with your friends and teacher. From this activity, you may have realized that our health depends on many factors. These factors include our lifestyle, which is how we live, and our environment, which is our surroundings.
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### 3.2.1 Maintain a healthy lifestyle
Now, students, let's discuss in detail how to maintain a healthy lifestyle. This is very important, so pay close attention.
First, eat a balanced diet with plenty of fruits, vegetables, and whole grains. A balanced diet gives our body all the nutrients it needs to function properly. Fruits and vegetables are rich in vitamins and minerals that boost our immunity and keep us strong. Whole grains like wheat, rice, and oats give us energy and help our digestive system work well.
Second, avoid processed, fatty, or sugary food and drinks. These might taste good, but they are not good for our health. Too much sugar can lead to diabetes, too much fat can cause heart problems, and processed foods often contain harmful chemicals. So, try to limit these foods and opt for natural, home-cooked meals whenever possible.
Third, stay physically active by playing outdoors, walking, running, cycling, or exercising. Physical activity is essential for keeping our body fit and our mind fresh. It helps us maintain a healthy weight, strengthens our bones and muscles, and improves our mood. So, make it a habit to play outside every day, at least for some time.
Fourth, limit screen time and spend more time in nature. Too much screen time can cause headaches, eye strain, and even depression. Spending time in nature, on the other hand, calms our mind and helps us relax. So, try to balance your screen time with outdoor activities.
Fifth, get enough sleep to help your body and mind rest and recover. Sleep is when our body repairs itself and our brain processes what we have learned during the day. Children your age should ideally sleep for 8 to 10 hours every night. So, make sure you have a proper sleep schedule.
Sixth, practice yoga or simple breathing exercises like pranayama regularly. These practices help calm our mind, reduce stress, and improve our concentration. They have been practiced in India for thousands of years and are now recognized all over the world for their benefits.
Finally, say "NO" to harmful substances like tobacco, alcohol, and addictive drugs. These substances can cause serious damage to our body and mind. They can lead to addiction, liver damage, lung diseases, and even death. So, it is very important to stay away from these harmful substances. Remember, saying "NO" to these things is one of the best decisions you can make for your health.
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### 3.2.2 Keep the environment clean
Now, students, let's talk about another important aspect of staying healthy — keeping the environment clean.
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### Activity 3.3: Let us compare
Look at the two playgrounds shown in Figure 3.3 in your book. One playground is clean, well-maintained, and looks beautiful. The other playground is polluted, dirty, unhygienic, and full of flies and mosquitoes. Which playground would you like to play in, and why? Most of us would like to play in the clean playground because it is pleasant and safe. The dirty playground can make us sick because of the germs and pollutants present there. People living in such areas may fall sick more often.
So, students, in addition to inculcating good habits and adopting a healthy lifestyle, we must keep ourselves and our surroundings clean. This means keeping our homes clean, not littering, and properly disposing of waste. Clean surroundings prevent the spread of diseases and make us feel good about ourselves.
Now, have you ever found it hard to breathe in a place with a lot of smoke or dust? That is because clean air and water are important for our health. In cities, air pollution from vehicles and factories can cause problems like coughing or asthma. The Air Quality Index, also known as AQI, helps us know how clean the air is. A cleaner environment helps us stay healthy and feel better. So, we should all do our part to keep our environment clean.
But health is not only about the body. Our feelings and relationships matter too. Even if we eat well and live in a clean place, we may not feel good if we are lonely or upset. Spending time with friends and family, talking, laughing, and having fun help keep our minds healthy too. So, students, remember that health is not just about the body — it is about the mind and our relationships with others as well.
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## 3.3 How Do We Know That We Are Unwell?
Now, students, let's learn about how we know that we are unwell. Our body usually works in a certain way to keep us healthy. When we feel unwell, it means something inside us may not be working as it should.
We may have symptoms, such as pain, tiredness, or dizziness, and signs like fever, rash, high blood pressure, or swelling that indicate we are unwell. Now, students, there is an important difference between symptoms and signs. A symptom is what we feel, like pain or tiredness. A sign is something that can be seen or measured, like high body temperature when we have fever, or a rash on the skin. These symptoms and signs help doctors understand what might be making us unwell. So, when you visit a doctor, it is important to tell them about both what you feel and what they can observe.
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## 3.4 Diseases: What Are the Causes and Types?
Now, students, let's move on to a very important topic — diseases. What is a disease? A disease is a condition that affects the normal working of the body or mind. It can happen when one or more organs or organ systems stop functioning properly.
Some diseases are caused by germs like bacteria, viruses, fungi, worms, or even by protozoa, which are single-celled organisms. These disease-causing organisms are called pathogens. Other diseases may result from poor nutrition or an unhealthy lifestyle. Some diseases last for a short time, while others can continue for a long time and need regular treatment or care.
Now, students, diseases can be grouped into two major types based on their causes and how they spread. Let's learn about them.
The first type is non-communicable diseases. Some diseases, like cancer, diabetes, or asthma, are not caused by pathogens and do not spread from one person to another. They are usually linked to lifestyle, diet, and/or environment. For example, eating too much sugar can lead to diabetes, smoking can cause cancer, and breathing polluted air can trigger asthma. These diseases are called non-communicable diseases.
The second type is communicable diseases. Diseases caused by pathogens are called communicable diseases. They can spread from one person to another. Some examples of communicable diseases are typhoid, dengue, flu, chickenpox, and COVID-19. These diseases are caused by bacteria, viruses, or other pathogens that can be transmitted from one person to another.
In recent years, non-communicable diseases like diabetes, heart disease, and cancer have become more common in India. This is happening because of changes in how people live, such as eating more processed food, getting less exercise, and living longer lives. Today, most deaths in India are caused by non-communicable diseases. Understanding the difference between these two types helps us know how diseases spread and how to prevent them. So, students, it is very important to be aware of both types of diseases.
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### 3.4.1 How are communicable diseases caused and spread?
Now, students, let's learn more about communicable diseases. All communicable diseases are caused by pathogens. These pathogens can enter our body through the air we breathe or by consuming contaminated food or water, and in many other ways. But how do these pathogens spread from one person to another?
One common way is through air. When an infected person coughs or sneezes, tiny droplets containing pathogens are released into the air. If we breathe in this air, we can get infected. Another way is through direct contact, like shaking hands with an infected person. Some pathogens can also spread indirectly by sharing personal items like towels, handkerchiefs, or utensils of an infected person.
Some of the communicable diseases spread through contaminated drinking water or food. If we eat or drink something that is contaminated with pathogens, we can fall sick. Some pathogens are also spread by insects like mosquitoes and houseflies. These insects are called vectors. For example, mosquitoes spread malaria, and houseflies can spread diseases like cholera and typhoid by sitting on food.
By understanding how diseases spread, we can take simple steps to protect ourselves and others. Let us find out how these communicable diseases spread and how we can prevent them.
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### Activity 3.4: Let us find out
Now, students, let's look at Table 3.1 in your book, which lists some common communicable diseases. This table contains information about the causal agent, site of infection, diseases, symptoms, and preventive measures for various diseases. Let me go through some of these with you.
First, let's look at diseases spread through the air. Common cold and influenza are caused by viruses and affect the respiratory tract. Symptoms include nasal congestion and discharge, sore throat, fever, cough, and body ache. Preventive measures include washing hands frequently, not sharing personal items, and covering the mouth and nose using a mask.
Chickenpox is also caused by a virus and affects the respiratory tract and skin. Symptoms include mild fever, itchy skin, rashes, and blisters. Preventive measures include complete isolation of the patient, covering the mouth and nose, and vaccination.
Measles is caused by a virus and affects the skin and respiratory tract. Symptoms include fever, sore throat, and reddish rashes on the neck, ears, and other parts of the skin. Preventive measures include isolation of the patient, covering the mouth and nose, maintaining good hygiene, and vaccination.
Tuberculosis, also known as TB, is caused by bacteria and affects the lungs. Symptoms include cough, fever, fatigue, loss of appetite, and night sweats. Preventive measures include avoiding close contact with TB-infected people, covering the mouth and nose, maintaining good hygiene, and getting vaccinated.
Now, let's look at diseases spread through contaminated water and food. Hepatitis A is caused by a virus and affects the liver. Symptoms include fatigue, fever, loss of appetite, nausea, vomiting, jaundice, and pain in the upper right abdomen. Preventive measures include drinking boiled water and vaccination.
Cholera is caused by bacteria and affects the intestine. Symptoms include diarrhoea and dehydration. Preventive measures include maintaining personal hygiene and good sanitary habits, consuming properly cooked food and boiled drinking water, and vaccination.
Typhoid is caused by bacteria and affects the intestine. Symptoms include headache, abdominal discomfort, fever, and diarrhoea. Preventive measures are similar to cholera.
Ascariasis, or roundworm infection, is caused by worms and affects the intestine. Symptoms include worms in stool, loss of appetite, poor growth, diarrhoea, weight loss, and anaemia. Preventive measures include maintaining personal hygiene and good sanitary habits.
Now, let's look at diseases transmitted by insects. Malaria is caused by a protozoa and affects the skin and blood. Symptoms include high fever, profuse sweating, and periodic chills. Preventive measures include using mosquito nets and repellents, wearing long-sleeved clothes, and controlling mosquito breeding in and around your home.
Dengue fever, also called breakbone fever, is caused by a virus and affects the skin and blood. Symptoms include fever, headache, muscle and joint pain, and nausea. Preventive measures are similar to malaria, plus avoiding areas with still water.
By studying this table, we can understand how infectious diseases spread and how to prevent them. Here are some simple but important precautions: keeping ourselves and our surroundings clean, practising basic hygiene every day, washing hands with soap and water to remove pathogens, covering our mouth and nose while coughing or sneezing, wearing a mask in crowded places, avoiding sharing personal items like towels and handkerchiefs, keeping our home, food, and water clean, and staying at home and resting when we are unwell.
Now, students, some infectious diseases are caused by worms that live inside our bodies, especially in the digestive system. They feed on nutrients and live as parasites, which are organisms that live in or on another living being. These worms usually spread through contaminated food, water, soil, or contact with infected people or animals. So, it is very important to maintain hygiene and eat clean food.
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### 3.4.2 How are non-communicable diseases caused?
Now, students, let's learn about non-communicable diseases. You learnt that non-communicable diseases like cancer, diabetes, and asthma are linked to lifestyle, diet, and/or environment. They are the most common cause of death in India.
In Grade 6, you also learnt about diseases like scurvy, anaemia, and goitre, which are caused by a lack of specific nutrients in the diet. These are called deficiency diseases and are also non-communicable. Deficiency diseases occur when our body does not get enough of a particular nutrient. For example, scurvy is caused by lack of Vitamin C, anaemia is caused by lack of iron, and goitre is caused by lack of iodine.
Diseases such as cancer, diabetes, and asthma may often persist for a long time, more than three months, and are referred to as chronic diseases. Chronic diseases require long-term management and care.
Diabetes is a common disease which is becoming more prevalent in adults as well as children. In fact, India now has one of the highest numbers of people with diabetes in the world. It often develops due to a combination of hormonal imbalances, unhealthy eating habits, lack of physical activity, being overweight or obese, and other reasons.
Let us learn more about the causes of non-communicable diseases and their prevention.
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### Activity 3.5: Let us survey
Now, students, let's do another activity. In this activity, you need to find out the three most common lifestyle-related diseases in your neighbourhood. Talk to a doctor, nurse, health worker, or even a family member who knows about health and what kind of lifestyle changes can help prevent or manage these diseases. You can also consult trusted health websites, books, teachers, and doctors. Then, fill in Table 3.2 in your book and learn more about lifestyle-related diseases.
Table 3.2 has columns for the name of common lifestyle-related diseases, signs and symptoms, and suggested lifestyle changes. For example, obesity is a common lifestyle-related disease. Its signs and symptoms include excessive weight gain, and the suggested lifestyle changes include eating a balanced diet and exercising regularly.
Diabetes has symptoms like frequent urination, excessive thirst, weight loss, tiredness, and slow healing. The suggested lifestyle changes include eating a balanced diet, exercising regularly, and maintaining a healthy weight.
High blood pressure is another common lifestyle-related disease. Its symptoms may include headaches, shortness of breath, and nosebleeds, and the suggested lifestyle changes include reducing salt intake, exercising regularly, and managing stress.
So, students, this activity will help you understand how lifestyle affects our health and what changes we can make to prevent or manage these diseases.
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## Be a scientist
Now, students, let me tell you about a great Indian scientist. Her name is Kamal Ranadive. She was a pioneering biomedical researcher who lived from 1917 to 2001. She studied how hormones and certain viruses are linked to cancer, helping improve its treatment and prevention. Her work also showed how tobacco, diet, and pollution can raise the risk of cancer, highlighting the importance of a healthy lifestyle. So, students, Kamal Ranadive's work teaches us that our lifestyle choices can have a big impact on our health, especially when it comes to diseases like cancer.
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## 3.5 How to Prevent and Control Diseases?
Now, students, let's learn about how to prevent and control diseases. You might have heard the phrase "Prevention is better than cure." It is very important to protect ourselves from both communicable and non-communicable diseases.
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### Activity 3.6: Let us read
Let's look at a case study from Odisha. In Bhadrak district, Odisha, a community sanitation campaign helped more people build and use toilets. This reduced open defecation significantly and improved child health, with fewer cases of diarrhoea and infections.
What do you infer from this case study? Simple steps like good sanitation can greatly reduce the spread of communicable diseases. This shows that when communities come together to improve sanitation and hygiene, it can have a huge positive impact on public health. Find about such community campaigns held in your location. Share in your class and discuss with your peers about the impact of such initiatives.
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### Ability of the body to fight diseases
Now, students, let's learn about how our body fights diseases. You would have noticed that some people get sick more frequently than others, although living in a similar environment. Do you know why? The natural ability of our body to fight diseases is known as immunity. Our body has a special system called the immune system that helps fight against diseases.
You might have taken some drops or injections in your childhood to protect yourself from certain diseases, such as polio, measles, tetanus, and hepatitis. These are vaccines that help prevent serious infections caused by viruses and bacteria.
A vaccine helps our body fight certain diseases by training the immune system to recognise and attack harmful germs, providing what is known as acquired immunity, which is protection developed after exposure to a pathogen or a vaccine. Vaccines can be made in different ways, from weakened or dead pathogens like viruses or bacteria, or from inactive or harmless parts of the pathogen. Some newer vaccines instruct our own body cells to make a harmless part of the germ, which our immune system then learns to fight.
For example, a tetanus shot, often given after an injury, protects against infection by the tetanus-causing bacteria. It contains an inactivated bacterial toxin that helps the immune system develop protection without causing the disease.
Now, do you know when the first vaccine was discovered? Let me tell you the fascinating story of Edward Jenner and the smallpox vaccine.
### Edward Jenner and the smallpox vaccine
Smallpox was a deadly disease that caused blisters and killed millions of people. A milder disease called cowpox, seen in cows, could also infect humans. In the late 1700s, English doctor Edward Jenner discovered that people who had cowpox did not get smallpox. This led to the invention of the first vaccine and helped protect people from smallpox.
### Our scientific heritage
Long before modern vaccines, India had a traditional method called variolation to protect against smallpox. It involved using material from a smallpox sore to scratch the skin and create a mild infection and build immunity. People who performed this practice were known as teekedaars. So, students, our country has a rich scientific heritage in the field of medicine and health.
### Think like a scientist
Now, let's think like a scientist and understand how Jenner made his discovery. His observations were that milkmaids who had cowpox did not catch smallpox, likely because the two viruses are related. His hypothesis was that the content in the pus of cowpox blisters protected people from smallpox. He tested this by injecting cowpox sap into a boy, who later showed no illness when exposed to smallpox. He found that people who were infected with cowpox sap were now resistant to smallpox. This discovery led to mass vaccination, which eventually helped eradicate smallpox worldwide.
Vaccines are one of the most effective ways to protect people of all ages, from infants to the elderly, against many serious diseases. They help prevent illnesses, reduce the spread of infections, and save millions of lives every year. It is important to remember that vaccines are preventive, not curative. They can help minimize serious diseases before they happen, but do not treat them once someone is already sick. Some people may fear or doubt vaccines, but scientists and doctors carefully test them for safety. Getting vaccinated not only protects you but also the people around you.
### Ever heard of India's role in vaccine production?
India is one of the world's largest vaccine producers. It manufactures vaccines on a massive scale and supplies them to many countries. Indian vaccine companies played a key role during the COVID-19 pandemic and continue to support global health efforts. So, students, we should be proud of India's contribution to global health.
### Be a scientist
Now, let me tell you about another great Indian scientist, Maharaj Kishan Bhan. He was a well-known Indian doctor and scientist. As Secretary of the Department of Biotechnology, he helped promote science and innovation in India. He played a key role in developing the Rotavirus vaccine, which protects children from diarrhoea. He believed in using research to create affordable healthcare and made a big difference in India's health and biotechnology sectors.
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## 3.5.1 Treatment of diseases
Now, students, let's learn about the treatment of diseases. If our immune system fails to protect us against an infectious disease, we fall ill and need to visit a doctor. The doctor may give us medicines called antibiotics, which kill the bacteria that might have caused the disease.
Antibiotics work only against bacterial infections because they target parts of bacterial cells that are different from human or other animal cells. They do not work against viruses or diseases caused by protozoa. This is a very important point to remember, students. Antibiotics are effective against bacteria, but not against viruses. So, if you have a viral infection like a cold or flu, antibiotics will not help.
### Think like a scientist: Discovery of the first antibiotic, Penicillin
Penicillin was discovered in 1928 by Alexander Fleming, a bacteriologist from London. While studying harmful bacteria, he noticed that a mould on a discarded petri dish stopped the bacteria from growing. He realized the mould released a substance that killed the bacteria. This chance discovery led to the discovery of penicillin, the first antibiotic used to treat bacterial infections. This is a great example of how scientific discoveries sometimes happen by accident, but they require a keen observation and curious mind.
Though antibiotics are effective in protecting us against bacterial infections and have saved millions of lives since their discovery, their indiscriminate use has led to a decline in their effectiveness. Nowadays, there are news headlines about antibiotic resistance, a phenomenon where bacteria that were earlier killed by a given antibiotic are found to survive and multiply despite treatment with that antibiotic. This makes common infections harder to treat and increases the risk of complications, prolonged illness, and even death.
Now, let's understand how antibiotic resistance spreads in the community. It can happen when people take antibiotics when they are not required or take an incomplete dose. This leads to the development of resistance in bacteria in animals and humans. Resistant bacteria can spread through animal food products, through soil in crop fields via manure, and it reaches the human digestive system through crop produce. In hospitals, resistant bacteria can spread directly to other patients or indirectly through healthcare workers. When patients go home, they can spread resistant bacteria to the community.
### How bacteria became resistant to antibiotics?
First, few bacteria develop resistance to antibiotics. Then, when antibiotics kill bacteria causing illness, they also kill good bacteria protecting the body from infection. The antibiotic-resistant bacteria grow and take over. Some bacteria transfer antibiotic resistance to other bacteria, causing more problems. This is how antibiotic resistance develops and spreads.
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### Activity 3.7: Let us infer
Now, students, let's do another activity. Study the infographic given in Figure 3.5b in your book. How do you think the antibiotic resistance has been developed in bacterial pathogens? What precautions may be taken to reduce antibiotic resistance?
To tackle the problem of antibiotic resistance, we must use antibiotics wisely, only when prescribed by a doctor, in the correct dose, and for the right duration. Avoiding unnecessary use helps prevent the rise of resistant bacteria and keeps antibiotics effective for future generations. So, students, always remember to take antibiotics only when prescribed by a doctor and complete the full course as advised.
Traditional medicine systems like Ayurveda, Siddha, and Unani have been used in India for many years to manage common health problems. They use natural substances like herbs, oils, and minerals for managing illnesses and promoting recovery, and focus on a healthy lifestyle and balanced diet. While these systems can help with some conditions and are useful for everyday well-being, they may not be effective for all diseases and at all stages.
Therapies for non-communicable diseases focus on managing symptoms and improving quality of life through medication, lifestyle changes, and rehabilitation. Early diagnosis and continuous care are key to control the disease progression and prevent complications.
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## Snapshots
Now, students, let's summarize what we have learned in this chapter with some key points.
Health means complete physical, mental, and social well-being, not just the absence of disease.
Being happy helps us stay active and healthy, and good health also improves our mood. Health and happiness are closely related.
A disease affects the normal working of the body or mind.
Symptoms are what we feel, like pain or tiredness. Signs are what can be seen or measured, like fever or rash.
Non-communicable diseases like diabetes and heart disease are caused by lifestyle and environmental factors, not germs. They can often be prevented with healthy habits, lifestyle changes, and regular exercise.
Infectious diseases are caused by pathogens like bacteria, viruses, or worms.
Our immune system helps protect us from harmful pathogens.
Vaccines train the immune system using dead, weakened, or harmless parts of a germ to prevent disease.
Diagnosis and treatment are important for managing and curing diseases.
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## Keep the curiosity alive
Now, students, let's answer some questions to check our understanding. These questions are given in your book under the "Keep the curiosity alive" section. Let's go through them one by one.
**Question 1:** Group the diseases shown in the images as communicable or non-communicable. The diseases are cold and flu, typhoid, diabetes, asthma, and chickenpox.
Let's answer this. Cold and flu are communicable diseases because they are caused by viruses and can spread from one person to another. Typhoid is also communicable because it is caused by bacteria and can spread through contaminated food and water. Diabetes is non-communicable because it is linked to lifestyle and does not spread from person to person. Asthma is non-communicable because it is usually caused by environmental factors and genetics, not by pathogens. Chickenpox is communicable because it is caused by a virus and can spread from one person to another.
So, students, communicable diseases from this list are cold and flu, typhoid, and chickenpox. Non-communicable diseases are diabetes and asthma.
**Question 2:** Diseases can be broadly grouped into communicable and non-communicable diseases. From the options given below, identify the non-communicable diseases. The options are (i) Typhoid, (ii) Asthma, (iii) Diabetes, (iv) Measles.
Typhoid is caused by bacteria and spreads through contaminated food and water, so it is communicable. Asthma is a non-communicable disease. Diabetes is also non-communicable. Measles is caused by a virus and spreads through the air, so it is communicable. Therefore, the correct answer is (b) (ii) and (iii), which are asthma and diabetes.
**Question 3:** There is a flu outbreak in your school. Several classmates are absent, while some are still coming to school coughing and sneezing.
(i) What immediate actions should the school take to prevent further spread?
The school should advise sick students to stay home, encourage everyone to wash their hands frequently, provide hand sanitizers in the classroom, ask students to cover their mouth and nose while coughing and sneezing, and consider temporarily closing the school if the outbreak worsens. The school should also inform parents about the outbreak and advise them to take their children to a doctor if they show symptoms.
(ii) If your classmate, who shares the bench with you, starts showing symptoms of the flu, how can you respond in a considerate way without being rude or hurtful?
You can politely suggest that your classmate should go to the school nurse or inform the teacher, as they might need to rest at home. You can also offer to help them catch up on their schoolwork later. It is important to be kind and supportive, not judgmental. You can say something like, "I think you should go to the nurse. I hope you feel better soon. Let me know if I can help you with anything."
(iii) How can you protect yourself and others from getting infected in this situation?
You can protect yourself by washing your hands frequently with soap and water, avoiding touching your face, covering your mouth and nose when coughing or sneezing, using a mask if necessary, and maintaining a healthy lifestyle to boost your immunity. You can also encourage others to follow these precautions.
**Question 4:** Your family is planning to travel to another city where malaria is prevalent.
(i) What precautions should you take before, during, and after the trip?
Before the trip, you should consult a doctor about malaria prevention medication, which is called chemoprophylaxis. You should also buy mosquito nets, repellents, and wear long-sleeved clothes. During the trip, use mosquito nets while sleeping, apply repellents on exposed skin, wear full-sleeved clothes, and avoid going outside during peak mosquito activity times, which is usually dawn and dusk. After the trip, if you develop fever or any other symptoms, you should immediately consult a doctor and inform them about your travel history.
(ii) How can you explain the importance of mosquito nets or repellents to your sibling?
You can explain to your sibling that mosquitoes spread malaria, which is a dangerous disease. Mosquito nets and repellents help keep mosquitoes away, which protects us from getting sick. You can say something like, "See, these mosquitoes are very small but they can make us very sick. This net keeps them away from us while we sleep, so we stay healthy and safe."
(iii) What could happen if travellers ignore health advisories in such areas?
If travellers ignore health advisories, they are at a high risk of getting infected with malaria. Malaria can be severe and even fatal if not treated promptly. It can also spread to other people if the infected traveller is bitten by mosquitoes in the new area. So, it is very important to follow all health advisories.
**Question 5:** Your uncle has started smoking just to fit in with his friends, even though it is well known that smoking can seriously harm health and even cause death.
(i) What would you say to him to make him stop, without being rude?
You can have a polite and caring conversation with your uncle. You can say something like, "Uncle, I care about your health and want you to be around for a long time. Smoking can cause many serious diseases like lung cancer and heart disease. I have read that it also affects the people around you through secondhand smoke. I think you are strong enough to say no to your friends. Maybe you can try chewing gum or doing some deep breathing when you feel the urge to smoke."
(ii) What would you do if your friend offers you a cigarette at a party?
You should firmly but politely say no. You can say something like, "No, thank you. I don't smoke, and I don't want to start. It is bad for my health." You can also suggest other activities like dancing or playing a game. Remember, it is always okay to say no to things that are harmful.
(iii) How can schools help prevent students from indulging in such harmful habits?
Schools can conduct awareness programs about the dangers of smoking and other harmful substances. They can invite doctors or ex-smokers to talk about their experiences. Schools can also promote healthy activities like sports, yoga, and meditation to keep students engaged and away from such habits. It is important to create a supportive environment where students feel empowered to make healthy choices.
**Question 6:** Saniya claims to her friend Vinita that "Antibiotics can cure any infection, so we don't need to worry about diseases." What question(s) can Vinita ask her to help Saniya understand that her statement is incorrect?
Vinita can ask questions like, "Do antibiotics work against viral infections like cold and flu?" or "What happens if we take antibiotics when they are not needed?" or "Have you heard about antibiotic resistance?" These questions will help Saniya understand that antibiotics only work against bacterial infections and that their misuse can lead to serious problems.
**Question 7:** The following table contains information about the number of dengue cases reported in a hospital over a period of one year. The table shows the number of cases for each month from January to December.
Make a bar graph of the number of cases on the Y-axis and the month on the X-axis. Critically analyse your findings and answer the following:
(i) In which three months were the dengue cases highest?
Looking at the table, the highest number of cases is 65, which occurs in July, August, and September. So, these are the three months with the highest dengue cases.
(ii) In which month(s) were the cases lowest?
The lowest number of cases is 10, which occurs in January. So, January had the lowest dengue cases.
(iii) What natural or environmental factors during the peak months might contribute to the increase in dengue cases?
The peak months of July, August, and September coincide with the monsoon season in India. During the monsoon, there is a lot of standing water in puddles, drains, and containers, which are perfect breeding grounds for mosquitoes. The humidity and warm temperature also help mosquitoes thrive. This leads to an increase in the mosquito population and, consequently, more dengue cases.
(iv) Suggest a few preventive steps that the community or government can take before the peak season to reduce the spread of dengue.
The community and government can take several preventive steps. They can conduct awareness campaigns about dengue prevention, encourage people to remove standing water from their surroundings, distribute mosquito nets and repellents, spray insecticides in mosquito-prone areas, and ensure proper drainage and waste management. It is important to start these measures before the monsoon season to prevent the breeding of mosquitoes.
**Question 8:** Imagine you are in charge of a school health campaign. What key messages would you use to reduce communicable and non-communicable diseases?
For communicable diseases, the key messages would be: wash your hands frequently with soap and water, cover your mouth and nose while coughing and sneezing, keep your surroundings clean, drink clean water, eat properly cooked food, get vaccinated, and stay home when you are sick.
For non-communicable diseases, the key messages would be: eat a balanced diet with plenty of fruits and vegetables, exercise regularly, avoid junk food and sugary drinks, get enough sleep, say no to tobacco and alcohol, manage stress through yoga or meditation, and go for regular health check-ups.
**Question 9:** It is recommended that we should not take an antibiotic for a viral infection like a cold, a cough, or flu. Can you provide the possible reason for this recommendation?
The reason is that antibiotics only work against bacterial infections, not viral infections. Taking antibiotics for viral infections does not help and can actually be harmful. It can lead to antibiotic resistance, where bacteria become stronger and no longer respond to antibiotics. This makes it harder to treat bacterial infections in the future. So, antibiotics should only be taken when prescribed by a doctor for a bacterial infection.
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**Question 11:** When our body encounters a pathogen for the first time, the immune response is generally low but on exposure to the same pathogen again, the immune response by the body is much more compared to the first exposure. Why is it so?
This happens because of our immune system's memory. When our body encounters a pathogen for the first time, it takes some time to recognize it and produce the right antibodies to fight it. However, our immune system remembers this pathogen. So, when the same pathogen enters our body again, our immune system recognizes it immediately and produces antibodies much faster and in larger quantities. This is called acquired immunity, and it is how vaccines work too. This is why we usually don't get some diseases like chickenpox more than once.
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## Discover, design, and debate
Now, students, there are some additional activities given in your book under this section. Let me go through them briefly.
First, students can maintain a health diary for at least a month to track food, hygiene, exercise, sleep, screen time, and emotional state. This will help them understand their habits and make improvements.
Second, you can read about Indian scientists like Suniti Solomon, Asima Chatterjee, Yellapragada Subbarao, and Mary Poonen Lukose for their contributions in the field of health and diseases. These scientists have made significant contributions to medical research and we can learn a lot from their work.
Third, the deadly disease smallpox was eradicated by vaccination. You can discover how this was done and why it worked, and debate whether everyone should be required to get vaccinated to protect others.
Fourth, according to current guidelines, you can learn the correct sequence of steps for performing cardiopulmonary resuscitation, also called CPR, on an adult in case of sudden stoppage of breathing. Your school may invite a doctor or a professional to demonstrate a mock drill.
Fifth, you can invite a doctor to the school. Students may be encouraged to interact with the doctor on the issues of malnutrition, under-nutrition, and over-nutrition.
Sixth, if you are given an opportunity to create a health card, what all would you like to include in it? Create your own health card and have a discussion about it.
Seventh, have a debate on "Are there ill-effects of fast food on companion animals?" This is an interesting topic that explores the impact of human food on pets.
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## Complete Summary
Now, students, we have come to the end of this chapter. Let me give you a complete summary of everything we have learned today.
In this chapter, we learned that health is not just the absence of disease but a state of complete physical, mental, and social well-being. We learned about the WHO definition of health and how our ancient Ayurvedic practices teach us about maintaining balance in body, mind, and surroundings through dinacharya and ritucharya.
We learned that to stay healthy, we must eat a balanced diet, exercise regularly, maintain personal hygiene, keep our environment clean, get enough sleep, practice yoga or meditation, and say no to harmful substances like tobacco and alcohol.
We learned about the difference between symptoms, which we feel, and signs, which can be seen or measured. We learned that diseases can be broadly classified into communicable diseases, which are caused by pathogens and can spread from one person to another, and non-communicable diseases, which are linked to lifestyle, diet, and environment and do not spread from person to person.
We learned about various communicable diseases, their causes, symptoms, and preventive measures. We learned that pathogens can spread through air, contaminated food and water, direct contact, and vectors like mosquitoes.
We learned about non-communicable diseases like diabetes, cancer, and asthma, and how they can be prevented through healthy lifestyle changes.
We learned about immunity and how vaccines help our body fight diseases by training the immune system. We learned about the history of vaccines, from Edward Jenner's smallpox vaccine to India's role in vaccine production.
We learned about antibiotics, how they work against bacterial infections, and the growing problem of antibiotic resistance due to their misuse. We learned that we should only take antibiotics when prescribed by a doctor and complete the full course.
We learned about traditional medicine systems like Ayurveda, Siddha, and Unani, and how they focus on natural remedies and a healthy lifestyle.
Finally, we answered several questions to test our understanding and learned about various activities we can do to further explore the topics in this chapter.
Students, health is indeed the ultimate treasure. It is the foundation of a happy and productive life. By following the principles we have learned in this chapter, we can protect ourselves and our loved ones from diseases and live healthy, fulfilling lives. Remember, prevention is always better than cure. So, take care of your health today, and it will take care of you tomorrow.
Thank you for listening so attentively. I hope you have understood everything in this chapter. If you have any questions, please feel free to ask me in the next class. Take care, stay healthy, and goodbye!