Tetanus: What Causes It and How People Get It

Tetanus is caused by Clostridium tetani. Its spores are common in the environment — in soil, dust and manure — and turn into active bacteria once they get inside the body.

How the spores get in

The spores enter through broken skin, usually from an injury. Some wounds are more likely to become infected than others:

• wounds contaminated with dirt, feces or saliva;
• puncture wounds, made by an object such as a nail or needle;
• injuries with dead tissue, such as burns, crush injuries and frostbite. Dead tissue is a particular concern because it can help the bacteria grow.

Less often, the spores get in through:

• chronic sores and infections;
• dental infections;
• insect bites;
• intravenous (IV) drug use;
• surgery.

Not contagious

Tetanus does not spread from one person to another.

It can happen twice

Having had tetanus before may not leave enough immunity to prevent another infection.

Prevention

The best protection is to stay up to date with recommended tetanus vaccinations and to get appropriate care after a wound.

Sources

• Centers for Disease Control and Prevention: "Tetanus: Causes and How It Spreads."