Public Health
Public Health tests prevention levels, immunization, surveillance, outbreak response, and health promotion within Cambodia's health system. Questions often ask what a district health team should do first.
Core rules
- Primary prevention reduces incidence; secondary prevention detects disease early; tertiary prevention limits disability.
- Cold chain: keep vaccines at 2–8°C; do not freeze DTP-containing or hepatitis B vaccines.
- Live vaccines are contraindicated in pregnancy and severe immunosuppression.
- Notifiable diseases must be reported promptly; outbreak investigation starts with case definition and line listing.
Worked example
A village reports a cluster of diarrhea. First define a case, count cases by time, place, and person, and calculate attack rates by water source. Then provide oral rehydration, chlorinate or advise boiling water, and report to the health center. Do not start mass antibiotics without evidence.
Traps
- Confusing incidence with prevalence in a community survey.
- Giving a live vaccine to a pregnant woman.
- Breaking the cold chain by freezing ice packs directly against vaccines.
- Failing to report a notifiable disease.