Topics: Community Medicine, Epidemiological Triad, Epidemiological Wheel, Epidemiological Studies, General Epidemiology, Epidemiological Study, Cohort Study, Therapeutic Trials, Clinical Trials, Ventilation, Air, water, Water Supply, Water Purification, Swimming Pool Hygiene, Housing, soil, Wastes, Refuse Disposal, Excreta Disposal, Sewerage System, Sullage Disposal, Physical Environment, Occupational Health, Physicochemical Agents, Physical Agents, Gastrointestinal Tract, Offensive Trades, offensive Occupations, Occupational Diseases, Occupational Hazards, Occupational Health Legislation, Employees State Insurance Act, Environmental Pollution, Air Pollution, Water Pollution, Radioactive Pollution, Thermal Pollution, Noise Pollution, Biological Environment, Rodents, Arthropods, Insect Control, Social Environment, Social Sciences, Cultural Anthropology, Social Psychology, Defense Mechanisms, Genetic Constitution, Nutritional Status, Psychological State, Personality, Communicable Diseases, Respiratory Infections, Viral Infections, Bacterial Infections, Water borne Infections, Food-borne Infections, Alimentary borne Infections, Cholera, Diarrhea, Food Poisoning, Enteric Fever, Brucellosis, Bacillary Dysentery, Shigellosis, Amebiasis, Giardiasis, Balantidiasis, Viral Hepatitis, Poliomyelitis, Contact Diseases, leprosy, Sexually Transmitted Diseases, Venereal Diseases, Acquired Immunodeficiency Syndrome, Trachoma, Fungus Infection, Arthropod-borne Diseases, malaria, Filariasis, Arboviruses, Yellow Fever, Chikungunya Fever, dengue, Japanese Encephalitis, Sandfly Fever, Leishmaniasis, Plague, Kyasanur Forest Disease, Epidemic Typhus, Trench Fever, Scrub Typhus, Tsutsugamushi Fever, Tick Typhus, Rocky Mountain Spotted Fever, Relapsing Fever, Noncommunicable Diseases, Food, Nutrition, Biostatistics, Research Methodology, Demography, Vital Statistics, Health Planning, Health Administration, Health Management, Health Economics, Maternal health, Child Health, Family Planning, Population Policy, School Health Services, Geriatrics, Mental Health, International Health, Biomedical Waste Management