The KPC Killer
In 2011, patients at the National Institutes of Health's Clinical Center began testing positive for a deadly organism. Even as it began claiming its first victims, two female scientists were on a desperate search to track it down.
Dr. Tara Palmore, deputy epidemiologist at the National Institutes of Health’s Clinical Center, remembers the apprehension she felt on June 13, 2011.
A 43-year-old lung transplant patient from New York had just arrived at the Bethesda hospital to take part in a research study on lung disease. Only hours earlier, a nurse reading her file noticed that the woman had tested positive for an organism called Klebsiella pneumoniae carbapenemase (KPC) and alerted Palmore. As a specialist in infectious diseases, Palmore knew what a nasty bug it was.
KPC, which first showed up in a North Carolina hospital about a decade ago, belongs to a class of germs that has adapted and evolved to resist pretty much every existing antibiotic. Once the organism gets into the bloodstream, it causes fever, chills, a bloody cough and, eventually, the shutdown of the body’s organs. The mortality rate is about 50 percent.
The NIH’s 243-bed hospital had experience with difficult-to-treat germs. It only admits patients who are participating in NIH studies, and some of them are among the sickest and most vulnerable to illness. But the NIH had never had a patient with KPC.
“We had read about how quickly and easily it had spread in [other] hospitals,” says Palmore, a petite, University of Virginia-educated physician with an earnest demeanor. “We put the staff on notice.”
Coincidentally, Julie Segre was thinking about antibiotic-resistant bacteria right about the time that Palmore was dealing with it. A Bethesda resident, Segre is a senior investigator with the National Human Genome Research Institute who works on the NIH’s Human Microbiome Project, which is studying the population of bacteria that live in and on our bodies and their role in human health. A tall, slender woman with a direct, warm manner, Segre specializes in the skin and genomics, which studies the DNA sequences of organisms and their traits, and she works out of a sun-filled office in a red brick building catty-corner to the NIH hospital.
Recently, her work had become personal.
A month earlier, Segre’s 4-year-old niece was in a West Coast hospital being treated for a chronic condition when she tested positive for methicillin-resistant staphylococcus aureus, the antibiotic-resistant bacteria commonly known as MRSA that has presented a threat in hospitals nationwide. Segre’s sister had to stay home from work, sanitize her house, separate her daughter from her siblings and treat her child with heavy doses of drugs. The child recovered. But Segre recalls her sister’s concern “that my niece had gotten this from the hospital.”
Because MRSA can be carried harmlessly on the skin, the hospital treating Segre’s niece declined to take responsibility for causing her illness. Segre, herself the mother of two daughters, was disturbed by the social implications of her niece’s experience.
“Hospital-acquired infections are eroding public confidence in hospitals,” she says. “I remember thinking that I could do something. …I could distinguish between a [bacteria] circulating around the hospital” and MRSA that was naturally occurring on the skin.
Palmore and Segre didn’t know it then, but they’d soon meet and become stars of a drama straight out of CBS’s CSI as they worked to stop a biological assassin on the loose at NIH. Not long after it arrived, KPC would quietly spread through the intensive care unit (ICU) and then elsewhere in the hospital, infecting 18 patients over 13 months. Twelve would die—seven from a bloodstream infection caused by the disease, and five from underlying conditions.
Palmore would play the gumshoe “detective” hot on the trail of a killer. Segre would be the laboratory specialist sifting through DNA evidence to provide her partner with clues.
Their story of scientific breakthroughs and a hospital-borne illness would end up on the front pages of newspapers, on television and radio programs, and in blogs across the country in August and September 2012.
“We had no idea what a big deal our work would be,” Segre says.
Almost as soon as antibiotics were introduced in the 1940s, bacteria developed the ability to become resistant to drugs. Thanks to the overuse of antibiotics worldwide, an increasing number of these resistant bacteria exist today. About 1 million people contract an infection at a hospital each year and 99,000 die as a result, according to the Centers for Disease Control and Prevention in Atlanta.
“Modern health care is inflicting an environment that is catering to these bugs,” says Dr. John Gallin, director of the NIH Clinical Center. “In other words, in order to make people better, we have to knock down their immune systems to do things like a bone marrow transplant, and that creates a whole community of patients who have compromised immune systems where these bugs can start taking over.”
For a while, drug companies invested in new drugs to stay ahead of the changing strains, but industry economics has shifted to favor drugs for chronic diseases such as diabetes, rather than pharmaceuticals that cure a disease in a few days or weeks. The Food and Drug Administration approved just three antibiotics between 2008 and 2011, compared with 16 between 1983 and 1987.
Only one drug, colistin, is known to treat KPC successfully, but it can be toxic to the kidneys. For that reason, it isn’t widely used. Also for that reason, KPC has yet to become resistant to the antibiotic, though there are signs that’s changing.
Currently, 6 percent of hospitals in the U.S. have treated a patient with a bug like KPC, but that number could grow, says Alexander Kallen, an epidemiologist at the CDC.
“We are approaching a post-antibiotic era,” says Dr. Eli Perencevich, an infectious disease specialist at University of Iowa Health Care and co-author of the widely read industry blog “Controversies in Hospital Infection Prevention.”
“We are literally, in some cases, out of antibiotics to treat [people],” he says.