The outbreak of the antibiotic-resistant bacteria known as Klebsiella pneumoniae was not made public until Wednesday, when NIH researchers published a scientific paper describing the advanced genetic technology they deployed to trace the outbreak.
This was “the proverbial superbug that we’ve all worried about for a long time,” said Tara Palmore, an infection control specialist at the Bethesda hospital.
With some 99,000 U.S. deaths attributed to hospital-borne infections annually, the NIH outbreak provides a stark case study of the dangers of the latest wave of hospital-bred bacteria and the extreme measures hospitals must adopt to stem the rising superbug tide.
The NIH Clinical Center now screens every patient transferring from another facility for superbugs, tests every patient in the intensive care unit twice a week and screens every patient monthly.
“This was our introduction to [antibiotic-resistant] Klebsiella,” Palmore said. “We hoped we would never see it.”
Clinical Center spokeswoman Maggie McGuire said the hospital did not alert the public earlier because Klebsiella infections do not trigger mandated reports to the Centers for Disease Control and Prevention like other infectious diseases do, such as HIV.
She also downplayed such outbreaks as too common to be newsworthy.
“There are . . . hospital-
acquired infections in almost every hospital in the country,” she said. “It’s happening everywhere.”
Nationwide, about 6 percent of hospitals are battling outbreaks of the class of superbugs known as carbapenem-resistant bacteria, which includes Klebsiella, said Alexander Kallen of the CDC. These bacteria usually live harmlessly in our intestinal tracts, and they pose little or no threat to patients with healthy immune systems. But in patients with compromised immune systems, the bacteria can turn dangerous, gaining an enzyme that defeats even the most powerful antibiotics. That’s what happened at NIH.
The six patients who died of bloodstream Klebsiella infections had immune systems weakened by cancer, anti-rejection drugs given after organ transplants, and genetic disorders.
The CDC detected this type of antibiotic-resistant bacteria in 2000. “Since then, we’ve seen it spread across the country,” Kallen said, to 41 states.
Later this year, the CDC is launching a program in 10 cities, including Baltimore, to watch for hospital-borne outbreaks of Klebsiella and related superbugs. CDC staff will review hospital records, Kallen said, and hospital labs will be asked to report any antibiotic-resistant bacteria to the CDC.