Risk factors

People who are at increased risk of catching diphtheria include:

• Children and adults who don't have up-to-date vaccinations
• People living in crowded or unsanitary conditions
• Anyone who travels to an area where diphtheria infections are more common

Diphtheria rarely occurs in the United States and Western Europe, where children have been vaccinated against the condition for decades. However, diphtheria is still common in developing countries where vaccination rates are low.

In areas where diphtheria vaccination is standard, the disease is mainly a threat to unvaccinated or inadequately vaccinated people who travel internationally or have contact with people from less-developed countries.