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Saturday, May 3, 2008

Watch what you touch: A bad germ gets worse

Scientists cultured the imprint of a health care worker's gloved hand after examining a patient infected with Clostridium difficile, known as C. diff. The larger yellow colonies outlining the fingers are clusters of the potentially deadly bacteria responsible for at least 300,000 infections a year in U.S. hospitals. The patient had showered an hour before the specimen was collected, say researchers.
Courtesy Dr. Curtis Donskey, Clinical Infectious Diseases, February 2008.

Amy Warren had never heard of the germ that made her so miserable.

In January 2005, weeks after giving birth to her daughter, the Ohio mother of two knew only that she was in pain, suffering cramping so severe she felt like she was still in labor. Then came the diarrhea, uncontrollable bouts up to 50 times a day, which left Warren weak and raw and stranded in her Maineville home.

"I was so sick; I thought I had colon cancer and was dying," Warren recalled.

Three tests failed to detect the source of her intestinal trouble. A fourth, however, confirmed Warren as part of a toxic trend: She was among growing numbers of people sickened by an especially virulent form of the bacterial infection Clostridium difficile, known as C. diff.

Doctors told Warren she’d contracted the NAP1 type of the bacteria, a mutated version that produces roughly 20 times the toxins responsible for illnesses ranging from simple diarrhea to blood poisoning — and death.

“It’s like a science fiction disease,” said Warren, who struggled for six months through three relapses before controlling the infection. “That’s what scared me. People die from this.”

C. diff has long been a common, usually benign bug associated with simple, easily treated diarrhea in older patients in hospitals and nursing homes. About 3 percent of healthy adults harbor the bacteria with no problem. But overuse of antibiotics has allowed the germ to develop resistance in recent years, doctors said, creating the toxic new type that stumps traditional treatment.

"This is the one we're scared of," said Dr. Brian Koll, chief of infection control at Beth Israel Medical Center in New York.

C. diff produces anaerobic spores transmitted through feces that are able to survive for months on most surfaces. People are infected when they ingest the bacteria, typically by touching contaminated surfaces and then touching their mouths, or by eating contaminated food.

Overall infections caused by C. diff more than doubled between 2000 and 2005, according to the latest government figures. In 2005, the year of Warren’s illness, 301,200 cases of C. difficile-associated disease (CDAD) were logged in discharge records kept by the nation’s hospitals. Some 28,600 people who had the infection died.

That's only hospitals, however. Counting nursing homes and other care centers, the number of cases nationally is likely closer to 500,000, experts estimate.

Contaminated health care settings remain the main source of C. diff infections, primarily because they treat so many people with serious diarrheal illness. The NAP1 strain has been found in other sites and populations in recent years, infecting young adults and pregnant women with no history of antibiotic use, according to federal sources.

Despite the concern, scientists don't know how many people contract NAP1 infections, or how many die from them. C. diff infection is not a reportable condition in most states, although a rare pilot project that mandated reporting in Ohio in 2006 found more than 14,000 cases in hospitals and nursing homes that year, according to the state health department.

Mutant strain detected in 38 states
What is clear is that the most toxic strain is taking hold, according to the federal Centers for Disease Control and Prevention.

In February 2007, 23 states told the CDC they'd seen cases of the NAP1 strain; by November, that number had grown to 38. Officials in the remaining states and territories contacted by msnbc.com said they hadn't detected the virulent bug, but most also said they don't look for it.

Better data about the scope of the C. diff problem may be available by this fall, when the Association for Professionals in Infection Control (APIC) presents the results of a prevalence study being conducted this month.

Last year, APIC was among the first agencies to note that rates of Methicillin-resistant Staphylococcus aureus, known as MRSA, were about 10 times previous estimates. The so-called superbug claimed headlines last year when researchers linked it to more than 94,000 infections and nearly 19,000 deaths in the U.S. in 2005.

States with  NAP1 strains of C. difficile, November 2007

Health officials now rank C. diff on par with MRSA as one of the top two infections acquired in hospitals.

“In light of how frequently it is already occurring as well as the trajectory of its recent increase, it is an infection that definitely deserves our respect and attention,” said Dr. L. Clifford McDonald, chief of prevention and response for a division of the CDC.

Attention must also be paid, scientists say, because the infection that mostly affects older, sicker people with long histories of antibiotic use now appears to be showing up in younger, healthier patients like Warren.

Warren’s not sure how she contracted the infection, which is caused when normal flora in the gut is disturbed, typically by antibiotics. About 90 percent of CDAD cases occur in patients who've used antibiotics recently, especially fluroquinolines such as the popular drug Cipro.

The resistance allows the C. diff bacteria to take over and flourish. Consequences can range from severe diarrhea to colitis and toxic megacolon, a condition that can lead to shock and death.

Image: Amy, C. diff victim, with her children
Courtesy Amy Warren
Amy Warren of Maineville, Ohio, smiled despite her illness in a 2005 photograph with her children, Shane and Celeste. Warren was 37 when she contracted a toxic strain of C. difficile after her baby's birth.

Warren, now 39, may have gotten the infection from her daughter, Celeste, who had a mild C. diff infection shortly after birth. Infants often harbor C. diff harmlessly in their intestines for about the first year of life, before more mature flora take over, experts said.

It's also possible Warren may have acquired the bacteria the previous fall, when she was briefly hospitalized and wound up sharing a room with a woman with severe diarrhea.

“I was sharing a bathroom with her,” Warren said.

‘Filthy’ hospitals perpetuate problem
There's no question that the rise of C. diff is tied to the cleanliness of the nation's hospitals, say researchers and health care advocates lobbying for better infection control.

"Outbreaks highlight the fact that standard infection control procedures in hospitals are not as good as they could be," said Dr. Curtis Donskey, director of infection control at the Louis Stokes Veterans Affairs Medical Center in Cleveland, Ohio.

Even after cleaning, studies show that C. diff spores linger on virtually every hospital surface, including bedrails, telephones, call buttons and toilets.

C. diff spores cling to patient skin, and not only in expected areas, such as the groin, according to a small-but-telling study published by Donskey and colleagues in the February issue of the journal Clinical Infectious Disease. Nearly 40 percent of patients diagnosed with CDAD infections tested positive for C. diff on their hands, and nearly 20 percent had the bacteria on their forearms, researchers found. About 60 percent had C. diff detected on their chest and abdomen.

Typical hospital germicides and alcohol hand sanitizers don’t kill C. diff, experts said. Instead, it takes bleach to eliminate it from surfaces and the friction of soap and water to remove it from hands.

But many hospitals have failed to make controlling C. diff a priority, critics contend.

“The biggest problem in our hospitals is that they are filthy dirty,” said Dr. Alfonso Torress-Cook, an epidemiologist who says he adopted practices that cut C. diff infections by 90 percent at his acute rehabilitation center in Orange County, Calif.

"If we start cleaning the environment, the infection will take care of itself," he added.

Interventions can range from ultra-violet light targeted to kill C. diff germs to silver-infused flooring and antimicrobial curtains aimed at resisting the bugs.

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