Community Health and Public Health Nursing
Community health questions test prevention levels, epidemiology, outbreak response, home visiting and health promotion. The focus is populations rather than individuals.
Core rules and concepts
- Levels of prevention: primary prevents disease before it occurs (immunisation, safe water); secondary detects early disease (screening, contact tracing); tertiary limits disability (rehabilitation, adherence support).
- Incidence is new cases divided by the population at risk over a period; prevalence is all existing cases at a point or over a period.
- Herd immunity protects unvaccinated people when a sufficient proportion is immune; the threshold depends on how contagious the pathogen is.
- Outbreak investigation: verify the diagnosis, define a case, identify cases, describe time, place and person, form a hypothesis, implement control and communicate.
- Home visiting: prioritise vulnerable groups such as pregnant women, infants, older adults and people with chronic illness.
- Health education: use plain language, involve the community and evaluate understanding.
Worked example
A district of 100,000 people records 50 new tuberculosis cases in one year. Incidence is 50 ÷ 100,000 = 50 per 100,000 person-years. If 300 people already have tuberculosis, prevalence is 300 per 100,000. Incidence measures risk of new infection; prevalence reflects the total burden.
Traps that cost marks
- Confusing incidence with prevalence.
- Calling screening primary prevention.
- Reporting raw case counts without a denominator.
- Designing health education without community participation.