Photo of K. pneumoniae via Vee Dunn/Flickr
America's antibiotic-resistant bacteria problem–a deadly bug known as K. pneumoniae, which ravaged National Institutes of Health Facilities last year, especially–is worse than the Centers for Disease Control estimates, particularly in hospitals and nursing homes, according to a new study published in a journal of the American Society for Microbiology.
Resistance rates for K. pneumoniae in hospitals were 15 percent according to a 2008 CDC report. Researchers at the Los Angeles Biomedical Research Institute now put them between 20 and 27 percent. E. coli resistance to last-ditch effort antibiotics in the CDC study was 5 percent, it's now between 8 and 11 percent; for A. baumaannii–a disease that emerged in military settings and causes pneumonia and blood infections–the rate has increased from 11 percent in the CDC estimate to more than 50 percent in the LA Biomedical estimate.
That development means "the carbapenems [a last line antibiotic] are already obsolete."
Brad Spellberg, one of the authors of the report, says the numbers aren't surprising and the CDC isn't trying to underestimate the problem: Researchers know that the antibiotic resistance will continue to worsen without the development of new drugs with different mechanisms of action.
"We're going to continue to have increasing deaths caused by untreatable infections. It's not rocket science," Spellberg said. "One of the nice things about Darwinian evolution is it's predictable. When you apply selective pressure with antibiotics, some of the bacteria adapt and then you've got resistance."
Last year, 18 people at the NIH's Clinical Center in Maryland contracted K. pneumoniae, seven of them died, and four others died of the illness they were being originally treated for. Tara Palmore, an epidemiologist at NIH, told the Washington Post that "no antibiotic worked."
Untreatable illnesses are most prevalent in hospitals and nursing homes, which makes lots of sense if you think about it. Many of them are overcrowded, patients there already have compromised immune systems, and catheters and IVs provide additional avenues for bugs to be transmitted.
In a way, antibiotics are victims of their own success. Misapplication of antibiotics–applying them when they aren't necessary–allows for mutations and evolution to take placem and has wide-reaching implications. Antimicrobial restitance even has implications for America's factory farms, where antibiotics are genorously given to livestock, but the global concern is for the future of health care. According to the World Health Organization, "a high percentage of hospital-acquired infections are caused by highly resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) or multidrug-resistant Gram-negative bacteria." The WHO warns that antimicrobial resitance puts modern medicine in danger of regressing to a "pre-antibiotic era," rendering centers for healing anything but.
"It's exactly what you think would happen–when you dump antibiotics into these people, you're going to breed out resistant bacteria," Spellberg said. "That's why hospitals are the epicenter for the pan-resistant stuff."
While America hasn't had to deal with a severe outbreak of anything untreatable on a community-wide scale, Spellberg says it's only a matter of time before one of these bugs gets out of the hospital and causes a crisis. In countries like South Africa and North Korea, tuberculosis is quickly becoming untreatable. There have also been cases of completely antibiotic-resistant gonorrhea.
"In communities, we're commonly seeing prostate, kidney, and abdominal infections where there's only a couple IV treatments left. We've lost all oral options," he said. "We don't know why K. pneumoniae is restricted to nursing homes and hospitals, and we don't know when it's going to stop. We're all waiting with bated breath to see when this is going to happen. There's no theoretical reason why it won't spread outside hospitals."
Besides standard evolution, there's a couple other reasons why antibiotic resistance has become such an urgent problem with no real solution in sight. The Food and Drug Administration has made it increasingly hard to get new antibiotics approved, a problem it recognized last year when the agency announced it would "reboot" how it goes about approving the drugs. Under those rules, getting a clinical trial approved was "infeasible or absurd" according to Spellberg, who wrote Rising Plague: The Global Threat from Deadly Bacteria and Our Dwindling Arsenal to Fight Them. Under those trials, patients weren't allowed to be enrolled until after hours of questioning.
"If you have a sick patient, you can't sit them there for six hours while you try to get them into a trial," he said. "Some of these trials were completely unenrollable."
In the early '80s, the FDA was approving a few new antibacterial agents each year. Between 2008 and 2012, it approved just three total. Besides the difficulty in getting a drug approved, it's also not economically beneficial for pharmaceutical companies to develop one. The most obvious antibiotics have already been developed, and the ones that remain cost millions of dollars of research and years to get approved.
"All the low hanging fruit has been plucked," he said. "The stuff that's easy to find has been found." The whole picture, it seems, continues to worsen.