Public Health Guides
Public health, from its history to today's challenges
Clear explainers on the ideas, discoveries and global agreements behind modern public health — written for students, health workers and curious readers, with references.
What Is Public Health? Definition, Scope and Why It Matters
Public health is the science and art of preventing disease, prolonging life and promoting health through the organised efforts of society. It protects whole populations rather than treating one patient at a time.
History of Public Health: From Ancient Sanitation to Modern Health Systems
Public health began with ancient drains, aqueducts and quarantine, grew through the sanitary movement of the 1800s, and became a science with germ theory, vaccines and modern health systems.
John Snow and the 1854 Broad Street Cholera Outbreak: Birth of Epidemiology
London physician John Snow mapped cholera deaths in Soho, traced them to a contaminated water pump on Broad Street and persuaded officials to remove its handle — a founding story of epidemiology.
Germ Theory of Disease: How Pasteur and Koch Changed Medicine
Louis Pasteur and Robert Koch proved that specific microbes cause specific diseases, replacing miasma theory and opening the way to vaccines, antiseptic surgery and laboratory diagnosis.
History of Vaccines: From Jenner's Smallpox Vaccine to mRNA
Vaccines began with Edward Jenner's cowpox experiment in 1796 and now include mRNA technology. Immunisation prevents an estimated 3.5–5 million deaths every year worldwide.
Smallpox Eradication: How the World Defeated a Deadly Disease
Smallpox killed an estimated 300 million people in the 20th century alone. A WHO-led global campaign using surveillance and ring vaccination eradicated it; WHO declared it eradicated in May 1980.
The Discovery of Antibiotics: Penicillin and the Golden Age of Medicine
Alexander Fleming noticed in 1928 that penicillin mould killed bacteria. Mass-produced in the 1940s, antibiotics transformed survival from infections — but their overuse now drives antimicrobial resistance.
History of Public Health in Nepal: From Bir Hospital to Federal Health System
Nepal's modern health system began with Bir Hospital in 1889, expanded through malaria eradication and immunisation, built a community-based network with FCHVs, and now operates under a federal structure.
The 10 Essential Public Health Services and Core Functions Explained
Public health agencies have three core functions — assessment, policy development and assurance — delivered through ten essential services, from monitoring health status to building a skilled workforce.
Social Determinants of Health: Why Where You Live Shapes How Long You Live
Social determinants of health are the conditions in which people are born, grow, work, live and age — income, education, housing, gender, caste and access to services — that drive most health inequalities.
Epidemiology Basics: Incidence, Prevalence, Study Designs and Outbreaks
Epidemiology studies how disease is distributed in populations and what determines it. Key measures are incidence and prevalence; key designs are cohort, case-control, cross-sectional and randomised trials.
Levels of Prevention: Primordial, Primary, Secondary, Tertiary and Quaternary
Prevention works at five levels: stopping risk factors from emerging (primordial), preventing disease (primary), detecting it early (secondary), limiting disability (tertiary) and avoiding over-medicalisation (quaternary).
Alma-Ata Declaration 1978: Primary Health Care for All Explained
The 1978 Alma-Ata Declaration called for 'Health for All by the Year 2000' through primary health care — essential, affordable, community-based services. The 2018 Astana Declaration renewed that commitment.
Ottawa Charter for Health Promotion 1986: Five Action Areas
The Ottawa Charter defined health promotion as enabling people to increase control over their health, and set out five action areas from healthy public policy to reorienting health services.
From MDGs to SDGs: How Global Health Goals Evolved (2000–2030)
The eight Millennium Development Goals (2000–2015) included three health goals. They were replaced by 17 Sustainable Development Goals in 2015, with SDG 3 covering health and well-being for all at all ages by 2030.
Universal Health Coverage (UHC): Meaning, Dimensions and Nepal's Progress
Universal health coverage means everyone can use the quality health services they need without financial hardship. It is measured by service coverage and by the share of people facing catastrophic health spending.
International Health Regulations (IHR 2005) and Global Health Security
The International Health Regulations (2005) are a legally binding agreement among 196 States Parties to detect, report and respond to public health risks that can cross borders, including declaring a Public Health Emergency of International Concern (PHEIC).
One Health: Linking Human, Animal and Environmental Health
One Health recognises that the health of people, animals and ecosystems is connected. About 60% of known infectious diseases and around three-quarters of emerging ones come from animals.
Antimicrobial Resistance (AMR): The Silent Pandemic Explained
Antimicrobial resistance happens when bacteria, viruses, fungi and parasites stop responding to medicines. Bacterial AMR was directly responsible for an estimated 1.27 million deaths in 2019.
COVID-19 Pandemic: Timeline and Lessons for Public Health
COVID-19 was declared a PHEIC in January 2020 and a pandemic in March 2020, and the emergency ended in May 2023. It exposed gaps in preparedness, equity and trust — and showed the power of science and community action.
Climate Change and Health: Heat, Dengue, Floods and Air Pollution
WHO calls climate change the single biggest health threat facing humanity. Rising temperatures, extreme weather, vector shifts and air pollution already affect health in Nepal and worldwide.
Non-Communicable Diseases (NCDs): The Leading Cause of Death Today
Non-communicable diseases — heart disease, stroke, cancer, diabetes and chronic lung disease — cause about 74% of deaths worldwide and around two-thirds of deaths in Nepal. Most are linked to five modifiable risk factors.
Mental Health as a Public Health Priority: Burden, Stigma and Solutions
Nearly 1 in 8 people worldwide live with a mental disorder, yet most receive no care. Integrating mental health into primary care and fighting stigma are key public health responses.
Digital Health and AI in Public Health: Opportunities and Risks
Digital tools — electronic records, DHIS2, telemedicine, mobile health and AI — are reshaping surveillance and care. They improve speed and reach but raise questions of privacy, equity and accuracy.
The Future of Public Health: Trends Shaping 2030 and Beyond
Ageing populations, climate change, pandemics, AMR, digital tools and rising inequality will define public health beyond 2030. Strong primary care, data and trusted communities remain the foundation.
Educational content by PHC-Nepal. It does not replace professional medical advice. Figures are drawn from the cited organisations and may be updated over time.