← Disease Detectives
0/4 sections complete done☰ All chapters
Stopping the Spread/Chapter 4
04

Strategies of Prevention

The scope and levels of prevention, mapped onto the natural history of disease

Prevention isn't one single action. It's a whole spectrum of interventions, each aimed at a different point along the natural history of disease you learned about in Topic 1. Lining the levels up against that timeline shows exactly what each one is trying to stop.

👆 Tap any segment below to reveal a real-world example of that level in action.

Before risk exists
Primordial Prevention

Change the underlying physical or social environment before risk factors even develop

Before disease
Primary Prevention

Stop disease before it starts: block exposure, or make people less likely to get sick (vaccines)

Early disease, no symptoms yet
Secondary Prevention

Screen and treat early, before symptoms appear, to stop progression

Clinical disease
Tertiary Prevention

Treat symptomatic illness to arrest, slow, or reverse its progress

Any stage
Quaternary Prevention

Protect patients from unneeded tests and treatment at any stage (not part of CDC's main list)

Tap a segment above to see a real-world example.

🚰 Try It: Matching Prevention to Level

A town discovers its well water is contaminated with bacteria that cause severe diarrhea. Which level of prevention does each response represent? Tap one to check yourself.

Notice how the same outbreak can be attacked at several levels at once. A permanent treatment plant and a temporary boil-water notice are both primary prevention, because each one stops people from being exposed to the bacteria. Primordial prevention works even earlier, on the conditions that create risk factors in the first place.

✓ Check Yourself

Q1A country limits salt and trans fats in packaged foods, so fewer people ever develop high blood pressure or high cholesterol. What level of prevention is this?

Q2Primary, secondary or tertiary prevention?