Which one among the following diseases in not caused by polluted water?

1. Classification of Human Diseases (basic)

Welcome to your first step in mastering human diseases! To understand how diseases impact our society, we must first understand what a disease actually is. At its simplest level, a disease is any condition that disrupts the normal functioning of the body or mind. This happens when our organs or organ systems stop working as they should Science Class VIII NCERT, Health: The Ultimate Treasure, p.32. In the world of medicine and public health, we classify these disruptions based on two main criteria: how they start and how they spread.

The most fundamental division is between Communicable and Non-communicable diseases. Communicable diseases are those caused by pathogens—tiny organisms like bacteria, viruses, fungi, and protozoa that act as "germs." Because these pathogens can travel, the disease can spread from one person to another Science Class VIII NCERT, Health: The Ultimate Treasure, p.32. On the other hand, non-communicable diseases (NCDs) are internal; they aren't "caught" from someone else but are instead linked to our genetics, lifestyle, diet, or environment. For example, while you might "catch" the flu from a friend, you cannot "catch" diabetes or asthma Science Class VIII NCERT, Health: The Ultimate Treasure, p.35.

Feature	Communicable Diseases	Non-Communicable Diseases
Cause	External pathogens (Bacteria, Viruses, etc.)	Lifestyle, genetics, or nutritional deficiencies
Spread	Can spread person-to-person	Cannot spread person-to-person
Examples	Typhoid, COVID-19, Chickenpox, Malaria	Diabetes, Cancer, Hypertension, Scurvy

As we dive deeper into infectious (communicable) diseases, we also look at modes of transmission. This is how the pathogen travels from a host to a new victim. Some pathogens are airborne, traveling through respiratory droplets when someone coughs (like the common cold or Tuberculosis). Others are waterborne, usually entering the body via the fecal-oral route when contaminated water or food is consumed (like Typhoid or Hepatitis A). Distinguishing between these routes is vital for public health because the strategy to stop an airborne disease (masks/ventilation) is entirely different from stopping a waterborne one (clean water/sanitation) Science Class VIII NCERT, Health: The Ultimate Treasure, p.33.

Sources: Science Class VIII NCERT, Health: The Ultimate Treasure, p.32; Science Class VIII NCERT, Health: The Ultimate Treasure, p.33; Science Class VIII NCERT, Health: The Ultimate Treasure, p.35

2. Bacterial and Viral Pathogens (basic)

To master the study of infectious diseases, we must first understand the microscopic agents that cause them, known as pathogens. While the word "germ" is often used colloquially, in science, we categorize these biological invaders based on their structure and behavior. The two most common types are bacteria and viruses. Bacteria are single-celled, living organisms that can survive on their own in various environments, including soil, water, and the human body. In contrast, viruses are much smaller and are not technically "alive" in the traditional sense; they are genetic material (DNA or RNA) wrapped in a protein coat that must hijack a living host's cells to reproduce Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.42.

These pathogens spread through different modes of transmission. Some travel through the air in tiny droplets when an infected person coughs or sneezes — these are airborne diseases like the Common Cold, Influenza, and Tuberculosis (TB). Others are waterborne, spreading when we consume contaminated food or water, often through the fecal-oral route. For instance, Typhoid is a classic bacterial disease spread through contaminated water, while Jaundice (Hepatitis A or E) is a viral infection typically transmitted the same way Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.32-33.

Understanding the causal agent is crucial because it determines how we treat the disease. Bacterial infections can often be cured with antibiotics, which kill the bacteria. However, antibiotics have no effect on viruses. Instead, we use vaccines to train our immune system to recognize and fight these pathogens before they cause serious harm Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.42.

Feature	Bacteria	Virus
Nature	Living, single-celled organism.	Non-living until it enters a host cell.
Examples	Typhoid, Tuberculosis, Anthrax.	Dengue, Common Cold, Chickenpox, Rabies.
Treatment	Antibiotics.	Vaccines (prevention) and Antivirals.

Sources: Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.32; Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.33; Science, Class VIII, NCERT (Revised ed 2025), Health: The Ultimate Treasure, p.42; Environment, Shankar IAS Academy, Animal Diversity of India, p.193

3. Mechanisms of Disease Transmission (intermediate)

To understand how diseases spread, we must first distinguish between communicable and non-communicable diseases. While non-communicable diseases like diabetes or asthma are linked to lifestyle and genetics, communicable diseases are caused by pathogens (like bacteria, viruses, or protozoa) that travel from an infected person or the environment to a healthy individual Science Class VIII NCERT, Health: The Ultimate Treasure, p.32. The "mechanism of transmission" is simply the bridge the pathogen crosses to reach a new host.

Transmission generally falls into three main categories based on the medium used:

• Airborne Transmission: When an infected person coughs, sneezes, or even speaks, they release tiny droplets containing pathogens. These can be inhaled directly by others or linger in the air as aerosols. Examples include COVID-19, Flu, and Tuberculosis (TB). While our bodies filter out much dust, these tiny infectious particles can bypass defenses and settle deep in the lungs Science Class VII NCERT, Life Processes in Animals, p.129.
• Waterborne and Foodborne Transmission: This often follows the fecal-oral route. Pathogens from infected waste contaminate water sources or food handled with poor hygiene. Consuming this leads to enteric (intestinal) diseases such as Typhoid, Cholera, and certain types of Jaundice (Hepatitis A and E) Geography of India Majid Husain, Contemporary Issues, p.25.
• Vector-borne Transmission: Here, a third party—usually an arthropod—acts as a carrier. Mechanical carriers like common houseflies pick up germs from filth and drop them on food. Biological vectors, like mosquitoes, carry the pathogen within their bodies and inject it directly into the bloodstream, as seen with Malaria and Dengue.

Understanding these pathways is critical for public health. For instance, while improving air quality helps combat respiratory issues, it won't stop a cholera outbreak; that requires clean water and sanitation. This distinction helps us target the right intervention for the right disease.

Mode of Transmission	Primary Vehicle	Common Examples
Airborne	Respiratory Droplets / Aerosols	Tuberculosis, COVID-19, Common Cold
Waterborne	Contaminated Drinking Water	Typhoid, Cholera, Hepatitis A
Vector-borne	Insects (Mosquitoes, Flies)	Malaria, Dengue, Filariasis

Sources: Science Class VIII NCERT, Health: The Ultimate Treasure, p.32; Science Class VII NCERT, Life Processes in Animals, p.129; Geography of India Majid Husain, Contemporary Issues, p.25

4. National Public Health & Sanitation Initiatives (intermediate)

In India, the battle against infectious diseases is fought as much through infrastructure as through medicine. Since approximately one-fourth of all communicable diseases in the country are water-borne — including diarrhea, intestinal worms, and hepatitis — the government has shifted toward a 'preventive healthcare' model INDIA PEOPLE AND ECONOMY, Geographical Perspective on Selected Issues and Problems, p.97. This approach recognizes that medical treatment alone cannot solve the crisis if the underlying environment remains contaminated by pathogens spread via the fecal-oral route. To tackle this, two major pillars of governance have emerged: Sanitation and Clean Water Access. The Swachh Bharat Mission (SBM), launched in 2014, operates on the core belief that sanitation is the foundation of public health. By aiming for Open Defecation Free (ODF) status, it directly reduces the environmental load of pathogens that cause diseases like cholera and typhoid A Brief History of Modern India, After Nehru..., p.781. Complementing this is the Jal Jeevan Mission (JJM), which prioritizes providing functional household tap connections to improve the 'ease of living' and safeguard rural populations from polluted water sources Contemporary India II, The Making of a Global World, p.55. Beyond basic access, specialized initiatives address specific environmental threats. The Jal Kranti Abhiyan, for instance, focuses on 'water-stressed' areas and the construction of arsenic-free wells, while the Namami Gange Programme seeks to clean the Ganga river, which supports one of the world's most densely populated regions but often acts as a carrier for water-borne pathogens INDIA PEOPLE AND ECONOMY, Water Resources, p.51. Collectively, these programs shift the focus from the National Health Mission's curative care to a holistic environmental management strategy.

Sources: INDIA PEOPLE AND ECONOMY (NCERT 2025 ed.), Geographical Perspective on Selected Issues and Problems, p.97, 103; A Brief History of Modern India (Spectrum 2019 ed.), After Nehru..., p.781; Contemporary India II (NCERT 2022 ed.), The Making of a Global World, p.55; INDIA PEOPLE AND ECONOMY (NCERT 2025 ed.), Water Resources, p.51

5. India's Immunization Programs (exam-level)

India’s immunization journey is one of the largest public health interventions in the world. It began in earnest with the Expanded Programme on Immunization (EPI) in 1978, which was later rebranded as the Universal Immunization Programme (UIP) in 1985. The core philosophy is to provide life-saving vaccines free of cost to all pregnant women and children. A major policy milestone was the National Population Policy (NPP) 2000, which transitioned the focus toward a more holistic approach, aiming for universal immunization of children against all vaccine-preventable diseases and reducing the Infant Mortality Rate (IMR) to below 30 per 1000 live births CONTEMPORARY INDIA-I, Geography, Class IX, NCERT (Revised ed 2025), Population, p.53.

To address the stagnation in full immunization coverage, the government launched Mission Indradhanush in 2014. Think of this as a "catch-up" campaign specifically designed to reach children and pregnant women who were missed during routine drives. While the UIP provides the vaccines, Mission Indradhanush provides the momentum. For other infectious threats like Malaria and Dengue, where vaccines may not be the primary tool yet, the government relies on the National Vectorborne Disease Control Programme, which emphasizes early detection and integrated vector management Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Natural Hazards and Disaster Management, p.80.

In the modern era, technology has become the backbone of delivery. During the COVID-19 pandemic, the digital platform Co-WIN proved that real-time tracking is possible. Building on this, the U-WIN platform has been developed to digitize the entire vaccination record system for the UIP. Furthermore, innovative financial tools like e-RUPI—a cashless, contact-less digital voucher—are being integrated into the vaccination framework to ensure subsidies and benefits reach the right person for the right purpose without leakage Indian Economy, Vivek Singh (7th ed. 2023-24), Money and Banking- Part I, p.79.

Program	Primary Objective
UIP	Routine, year-round vaccination against 12+ preventable diseases.
Mission Indradhanush	Targeted drives to achieve 90% full immunization coverage in high-risk areas.
NVBDCP	Prevention and control of vector-borne diseases like Malaria, Dengue, and Kala-azar.

Sources: CONTEMPORARY INDIA-I, Geography, Class IX, NCERT (Revised ed 2025), Population, p.53; Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Natural Hazards and Disaster Management, p.80; Indian Economy, Vivek Singh (7th ed. 2023-24), Money and Banking- Part I, p.79

6. Characteristics of Waterborne Diseases (intermediate)

Waterborne diseases are conditions caused by pathogenic microorganisms—including bacteria, viruses, and protozoa—that are most commonly transmitted through contaminated fresh water. The fundamental characteristic of these diseases is the fecal-oral route of transmission. This occurs when pathogens from the excreta of an infected person contaminate a water source which is subsequently ingested by others, often due to inadequate sanitation or poor hand hygiene Geography of India, Majid Husain, Contemporary Issues, p.25. In regions with frequent flooding or poor drainage, these pathogens can spread rapidly, leading to major public health crises. To master this concept, we must categorize these diseases by their causative agents. Bacterial infections like Cholera (Vibrio cholerae) and Typhoid are the most notorious. Cholera is characterized by an acute infection of the small intestine, leading to massive, rapid depletion of body fluids and salts through vomiting and diarrhea Environment and Ecology, Majid Hussain, Natural Hazards and Disaster Management, p.80. On the other hand, viral waterborne diseases like Hepatitis A and E (often manifesting as Jaundice) are highly stable in water and typically spread via sewage-contaminated supplies.

Disease Category	Common Examples	Primary Pathogen Type
Enteric Fevers	Typhoid, Paratyphoid	Bacteria
Intestinal Infections	Cholera, Dysentery, Diarrhea	Bacteria / Protozoa
Viral Hepatitis	Jaundice (Hepatitis A & E)	Virus

A critical distinction for civil services aspirants is the difference between "waterborne" and "airborne" diseases. While some older environmental literature might broadly group various ailments under the umbrella of pollution-related issues Environment and Ecology, Majid Hussain, Environmental Degradation and Management, p.37, modern medicine classifies Tuberculosis (TB) strictly as an airborne disease. TB is caused by Mycobacterium tuberculosis and spreads through respiratory droplets when an infected person coughs or sneezes, rather than through the ingestion of water. Understanding this classification is essential for identifying the correct intervention strategies in public health administration.

Sources: Geography of India, Contemporary Issues, p.25; Environment and Ecology, Majid Hussain, Natural Hazards and Disaster Management, p.80; Environment and Ecology, Majid Hussain, Environmental Degradation and Management, p.37

7. The Science of Tuberculosis (TB) (exam-level)

Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis. Unlike many other common infections that target the digestive tract, TB primarily attacks the lungs (pulmonary TB), although it can spread to other parts of the body like the spine, kidneys, and brain. Understanding its transmission is critical for public health: TB is strictly an airborne disease. It spreads when an infected person releases microscopic droplets into the air through coughing, sneezing, or even speaking. This distinguishes it from enteric diseases like Typhoid or Cholera, which are transmitted via the fecal-oral route through contaminated food and water Science Class VIII NCERT, Health: The Ultimate Treasure, p.34.

From a clinical perspective, TB is characterized by a persistent cough (often lasting more than three weeks), chest pain, night sweats, fatigue, and significant weight loss. Because the bacteria can remain dormant in the body for years—a state known as latent TB infection—the disease may not manifest until the immune system is weakened. Prevention strategies focus on early diagnosis, maintaining respiratory hygiene, and the BCG (Bacillus Calmette-Guérin) vaccine, which is a staple in India’s Universal Immunisation Programme Science Class VIII NCERT, Health: The Ultimate Treasure, p.34.

It is important to clear a common misconception: while some broad environmental texts might group TB with "diseases influenced by living conditions," modern medical science classifies it as a respiratory infection, not a waterborne one. Diseases like Hepatitis A and Jaundice result from viral contamination of water supplies, whereas TB transmission is tied to air quality and close physical proximity in poorly ventilated spaces Geography of India Majid Husain, Contemporary Issues, p.25.

Feature	Tuberculosis (TB)	Typhoid / Cholera
Causative Agent	Bacteria (M. tuberculosis)	Bacteria (S. Typhi / V. cholerae)
Primary Mode	Airborne (Respiratory droplets)	Waterborne (Fecal-oral route)
Main Organ Affected	Lungs	Intestines

Sources: Science Class VIII NCERT, Health: The Ultimate Treasure, p.34; Geography of India Majid Husain, Contemporary Issues, p.25

8. Solving the Original PYQ (exam-level)

Review the concepts above and try solving the question.