Community Health and Hygiene: Prevention, Sanitation, and Epidemiology
What this domain tests
This section tests primary health care, prevention levels, sanitation, immunisation, and basic epidemiology.
Core rules and concepts
- Primary prevention stops disease before it starts: immunisation, safe water, health education, nutrition, exercise.
- Secondary prevention detects disease early: screening, Pap smear, blood pressure checks, sputum testing.
- Tertiary prevention limits disability: rehabilitation, physiotherapy, support groups.
- Levels of care: primary (PHC/sub-centre), secondary (district hospital), tertiary (specialist hospital).
- Safe water: chlorination, boiling, filtration. Sanitation: safe excreta disposal, handwashing, vector control.
- Herd immunity protects unvaccinated people when a high proportion is immune.
Worked example
A village reports diarrhoea cases. A nurse finds a well near a pit latrine. Reasoning: the likely route is contaminated water (faecal–oral). The action is primary prevention: protect the well, chlorinate water, teach handwashing, and promote safe excreta disposal. Screening patients is secondary prevention, but it does not stop the source.
Traps that cost marks
- Calling screening "primary prevention".
- Confusing incidence (new cases) with prevalence (all existing cases).
- Blaming food when water is the common source.
- Forgetting that immunisation is primary prevention.