Risk factors

Although people who have no known risk factors have gotten sick from C. difficile, certain factors increase the risk.

Taking antibiotics or other medications

Your intestines contain about 100 trillion bacterial cells and between 500 to 2,000 different kinds of bacteria, many of which help protect your body from infection. When you take antibiotics to treat an infection, these drugs tend to destroy some of the helpful bacteria in your body in addition to the bacteria causing the infection.

Without enough helpful bacteria to keep it in check, C. difficile can quickly grow out of control. While any antibiotic can be implicated, the antibiotics that most often lead to C. difficile infection include:

• Clindamycin
• Cephalosporins
• Penicillins
• Fluoroquinolones

Proton pump inhibitors, a type of medicine used to reduce stomach acid, also may increase your risk of C. difficile infection.

Staying in a health care facility

The majority of C. difficile infections occur in people who are or who have recently been in a health care setting — including hospitals, nursing homes and long-term care facilities — where germs spread easily, antibiotic use is common and people are especially vulnerable to infection. In hospitals and nursing homes, C. difficile spreads on:

• Hands
• Cart handles
• Bedrails
• Bedside tables
• Toilets and sinks
• Stethoscopes, thermometers or other devices
• Telephones
• Remote controls

Having a serious illness or medical procedure

Certain medical conditions or procedures may make you more susceptible to a C. difficile infection, including:

• Inflammatory bowel disease
• Weakened immune system from a medical condition or treatment (such as chemotherapy)
• Chronic kidney disease
• Gastrointestinal procedure
• Other abdominal surgery

Other risk factors

Older age is a risk factor. In one study, the risk of becoming infected with C. difficile was 10 times greater for people age 65 and older compared with younger people.

Having one C. difficile infection increases your chance of having another one, and the risk continues to increase with each infection.

Women are more likely than men to have C. difficile infection, for reasons that are not clearly understood.