Cases of potentially deadly diarrheal infections jumped by more than 200 percent in the nation’s hospitals between 2000 and 2005, fueling new worries about the next bad bug.
Some 301,200 people contracted Clostridium difficile-associated disease — known as CDAD — in 2005, more than twice as many as previously counted, and 28,600 people died from the infection that year, according to a new report by the federal Agency for Healthcare Research and Quality.
That sharp spike follows a 74 percent increase in the number of CDAD cases recorded between 1993 and 2000. Overall, more than 2 million patients contracted the serious intestinal infection between 1993 and 2005, the report showed.
“It is the next major germ threat,” said Betsy McCaughey, the former lieutenant governor of New York state who now heads the Committee to Reduce Infection Deaths — RID — an agency that focuses on improving infection control in hospitals and health care settings.
The bacterium, commonly referred to as C. diff, is as worrisome as Methicillin-resistant Staphylococcus aureus, or MRSA, a drug-resistant infection linked to more than 94,000 infections and nearly 19,000 deaths in the U.S. in 2005, McCaughey said.
C. diff can cause infections that range from mild diarrhea to an often deadly illness that can be treated only by completely removing a patient’s colon. It develops when the normal flora in the human gut is disturbed, typically by previous use of antimicrobial drugs, followed by exposure to the C. diff bacteria.
The infection frequently targets elderly people: two out of three patients who contracted C. diff in 2005 were older than 65, the AHRQ report showed. The death rate among CDAD patients was 9.5 percent, compared to about 2 percent overall.
C. diff spores linger on surfaces
C. diff produces spores that can linger on surfaces such as bedpans, toilet seats or floors for weeks. It’s spread by touch, often by patients who acquire the fecal bacteria from improperly cleaned hospital rooms.
“It’s on every surface,” McCaughey said. “They get the spores on their hands and their food arrives and they ingest the spores with their dinner rolls.”
Alcohol sanitizers are ineffective against the spores, which must be killed with bleach, she added.
It’s not clear how much of the spike in CDAD cases was caused by more complete reporting of the hospital discharge data, said Dr. Michael Jhung, an epidemiologist with the federal Centers for Disease Control and Prevention who analyzed the data.
What is clear, however, is that CDAD was more frequently listed as the primary or secondary condition at discharge, he added. Researchers used statistics from the Nationwide Inpatient Sample, a database of hospital stays that include about 90 percent of all U.S. discharges.
Virulent strain is 20 times more toxic
The data didn’t include specific information about a new, virulent strain of C. diff estimated to be about 20 times more toxic than previously known strains. The North American Phenotype 1/027 strain has been responsible for deadly outbreaks of the infection in Europe, Canada and the U.S. during the past several years.
“We do suspect that the virulent strain is increasing,” Jhung said.
CDAD can be resistant to many frontline antibiotics, forcing use of the stronger vancomycin. But some infections are resistant to that drug as well, making them difficult or impossible to cure.
The best treatment is prevention, McCaughey said. Hospitals must improve their hygiene practices and patients must be vigilant about not touching surfaces and keeping their hands out of their mouths.
“This is a killer bacterium and we can’t be lazy about it,” she said.