Communicable and Non-Communicable Disease Control
Core concepts
Communicable disease control requires understanding chain of infection (agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host), isolation precautions, immunization, surveillance, and outbreak investigation. Non-communicable diseases (NCDs) require risk-factor modification (tobacco, diet, physical activity, alcohol), screening, and chronic care models. Know notifiable diseases and contact tracing.
Traps in questions
- Breaking the wrong link in the chain of infection.
- Confusing standard with transmission-based precautions.
- Missing herd immunity thresholds.
- Overlooking social determinants in NCDs.
- Failing to report notifiable diseases promptly.
Worked example / rule of thumb
A tuberculosis case in a crowded shelter: priority is case finding, isolation, contact tracing, and treatment adherence. Rule of thumb: for communicable disease, interrupt the chain at the most feasible link; for NCDs, modify risk factors and screen early.
Key teaching points
Chain of infection guides control. Surveillance and reporting are legal duties. NCD control targets shared risk factors.