Conclusion

1. Public health strategies aim to prevent disease or reduce its impact by taking actions to protect or promote the health and wellbeing of the population as a whole, in contrast to medical strategies for treating disease in its individual members.
2. The global burden of infectious disease remains a significant threat to health, economic development and equity of opportunity, particularly (but not exclusively) in low- and middle-income countries and disproportionately among young children.
3. A systematic and evidence-based approach to addressing threats to public health began with the sanitarian movement in England in the nineteenth century and remains the basis for public health strategies today.
4. Public health approaches to infectious diseases focus on one or a combination of:
   • screening, surveillance, monitoring and reporting of disease outbreaks
   • community education to promote health-related behaviour change
   • increasing the resistance of the human host to infection, e.g. through vaccination and nutritional support
   • community mobilisation to tackle sources of infection in the environment
   • case finding, case containment and (where necessary) isolation of infectious individuals.

5. Vaccination, the provision of clean drinking water and improved sanitation, the promotion of personal and institutional hygiene (particularly the importance of handwashing with soap), and the organisation of surveillance and response strategies to detect and control disease outbreaks are integral to the public health approach. Raising sustainable living standards, improving the quality of housing, nutrition and education, and promoting gender equality and personal security are also important public health goals.

6. International health regulations (IHRs), including trade and travel agreements, and the work of international organisations (e.g. the WHO) contribute at a global level to public health approaches to infectious disease.
7. Three levels of prevention of infectious diseases can be identified in a public health context. Primary prevention aims to prevent new cases from occurring; secondary prevention aims to treat the disease at the earliest stage to prevent it from spreading; and tertiary prevention aims to alleviate the worst effects of an established disease in an individual, which may indirectly benefit the rest of the community.

8. Community participation and community health workers with minimal training and equipment are central to the success of infection-control campaigns in many parts of the world, and particularly in low- and middle-income countries.

   The importance of community action is illustrated by the success of the rural Health Extension Programme in Ethiopia (Video 1), the reduction in healthcare-associated infections (HCAIs) in the UK, and the worldwide eradication campaigns against smallpox, polio and guinea worm disease.

Despite the undoubted progress of recent decades, the prospects for meeting international targets in relation to infectious disease and public health are constrained by many factors. In addition to poverty, poor housing and food insecurity, they include:

• the biological adaptability of infectious agents, which enables the rapid evolution of new more virulent strains and resistance to chemical controls
• the lack of finance for basic infrastructure to provide sanitation and piped water, vaccination, soap, bed-nets and other preventive measures
• the shortage of essential skills, scientific and technological knowledge, trained personnel and equipment
• difficult circumstances of geology and climate and the risks posed by major natural disasters – drought, flooding, earthquakes, etc.
• the level of illiteracy and gender inequality in a population, which can limit the effectiveness of health education initiatives
• the extent to which political will, social stability and community action can be harnessed to promote health and overcome resistance to behavioural change.

However, there are hopeful signs: the advances that delivered such large improvements in public health in high-income countries in the twentieth century are being applied in low- and middle-income countries with substantial success, as several of the examples in this course have demonstrated.