Your blood is bad means you have syphilis" poster
The pattern
This still is filed under Public health warning.
Define
A warning designed to change a health behavior (stop, screen, stay home), not to sell a brand.
Mechanism
Fear with a next step. The threat is specific. The action is doable today. Fear without an action is cruelty.
Verdict
The risk is real and the action is clear. Official or civic voices help.
Why it works
It directly confronts a common euphemism ('bad blood') with the harsh medical reality (syphilis). The stark, clinical visual of the test tube reinforces the seriousness and medical nature of the condition.
Steal this when
You need to cut through jargon or euphemisms to deliver a critical, potentially uncomfortable truth.