Dangerous bug spreads fast at local hospitals

A dangerous intestinal bug that is on the upswing across the country has also become more prevalent in Washington.

The bacterium, which most frequently strikes people in hospitals and nursing homes, contributed to 4,100 hospitalizations in the state in 2006, more than twice the number in 2000. That mirrors a nationwide trend, which saw infection rates double at the same time a deadlier strain of the germ emerged.

"We're all seeing more cases," said Marcia Patrick, director of infection prevention and control at MultiCare Health System in Tacoma. "It's something we need to be very, very careful about."

The pathogen, called Clostridium difficile, or C-diff for short, is responsible for more deaths in the United States than all other intestinal infections combined.

The bug lives in the colon, where it is normally kept in check by other bacteria. But treatment with some types of antibiotics wipes out beneficial bacteria, allowing C-diff to proliferate out of control. The disease causes diarrhea and can lead to colitis, a more serious condition that can require surgery to remove damaged bowel segments.

A "hypervirulent" strain that became more common around 2000 produces up to 20 times more toxin than the ordinary form of C-diff and may also be harder to kill with antibiotics.

The infection spreads by spores in feces. "The spores are like the M&Ms of the germ world, with a hard shell," Patrick said. "It's very hard to kill them."

The spores also can linger in the digestive tract and cause recurrent bouts of diarrhea.

At least one case of the more virulent strain has been reported in Washington, from the Veterans Affairs Medical Center in Seattle. The hospital experienced a small outbreak of disease in 2006, which officials said may have contributed to the death of one patient.

Nationally, the number of people hospitalized with C-diff infections has been growing by more than 10,000 cases a year, according to a study in the June issue of Emerging Infectious Diseases, a publication of the Centers for Disease Control and Prevention.

Emergence of the virulent strain certainly plays a role in the increase, said Marya Zilberberg, a University of Massachusetts researcher and lead author of the study. "Also, our population is aging and we have more chronic disease, which certainly predisposes you to this disease," she said. Though the infection can strike at any age, it is most common in people age 65 and older. Overuse of antibiotics has also contributed to the disease's spread, Zilberberg said.

She and her colleagues based much of their analysis on a sample of hospital data reported to the federal government.

The researchers concluded that 2.2 percent of the cases in 2004 were fatal — about 5,500 deaths. That was nearly double the percentage of C-diff-related cases that ended in death in 2000.

Many of the people who died had other health problems. The study did not try to determine whether Clostridium difficile was the main cause of death in each case, Zilberberg said.

In Washington, 259 people infected with C-diff died in 2006 — though the infection may not have been the primary cause of death.

After watching the number of cases soar over the past several years, hospitals across the state have beefed up their infection-control programs, said Dr. Tim Dellit, medical director of infection control at Harborview Medical Center in Seattle.

Patients with C-diff are kept in single rooms. Workers now use dilute bleach — which can kill spores — to mop floors in some areas. And use of antibiotics has been scaled back, Dellit said.

As a result, the number of cases began dropping last year, he said.

And while some call C-diff a "superbug," most infections can be cured by the right type of antibiotic treatment in most cases, said Lynne McFarland, an expert on the disease at the VA Medical Center in Seattle.

"I would call it a serious bug, not a superbug," she said.

The U.S. West Coast has yet to see the types of acute outbreaks that have swept through Canada, where more than 250 recent deaths in Ontario hospitals were blamed on the disease. More than 1,000 deaths in Quebec also were linked to the bacterium.

"I was wringing my hands back then, but the good news is that it's not sweeping across the U.S.," McFarland said. "But we have to remain vigilant."

Seattle Times reporter Michael Berens and The Associated Press contributed to this report.

Sandi Doughton: 206-464-2491 or sdoughton@seattletimes.com