Deadly gut bacteria cause half a million infections every year

Nearly half a million cases of the difficult-to-treat and sometimes deadly infection called "C. diff" now occur yearly in the United States, according to a new report from the Centers for Disease Control and Prevention.

Researchers found that in 2011, Americans had an estimated 453,000 infections with the bacteria Clostridium difficile, or C. difficile, which can cause severe diarrhea, and frequently comes back after treatment.

About two-thirds of these cases occurred among people in hospitals, the report found. About 1 in 5 people who acquired the bacteria in a hospital experienced a reoccurrence of their disease, and about 29,000 of all the people who contracted C. difficile died within a month of their diagnosis.

"This is a very severe illness that causes tremendous suffering, and death," Dr. Michael Bell, deputy director of the CDC's Division of Healthcare Quality Promotion, said in a news conference.

Infections from C. difficile have been on the rise in recent years, and a strain of the bacteria that causes more severe disease has become more common, Bell said. The bacteria produce a powerful toxin that can damage the colon, and cause leakage from the colon into the bloodstream, which can be life-threatening, Bell said.

Most cases of C. difficile occur after people take antibiotics, which disturb the normal balance of gut bacteria, and "increase the opportunity for C. difficile to take over," Bell said.

Although most cases of C. difficile are acquired in hospitals, the study found that in only about 25 percent of cases did patients actually start showing symptoms while in the hospital — the rest began while a patient was in their home, often after they were released from the hospital.

In addition, nearly 160,000 cases occurred in people who had not been hospitalized. Previous studies have found that most of these cases happen when a person visits their doctor or dentist and is prescribed antibiotics, Bell said. For this reason, it's important that people who get symptoms of diarrhea after using antibiotics take it "very seriously," he said.

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