Increasingly at risk from a nightmare bacteria
Federal health officials warned last week that the nation’s hospitals and nursing homes are increasingly at risk from deadly new strains of drug-resistant bacteria that can’t be treated with even the strongest antibiotics. So far, the infections have been confined to a small number of the sickest patients in hospital wards, but authorities at the Centers for Disease Control and Prevention say there is only a “limited window of opportunity” to halt the spread of these “nightmare bacteria” into the wider population.
That would represent a medical and public health catastrophe. In 2011, an outbreak of one drug-resistant “superbug,” a type of bacteria that lives in the gut called Klebsiella, infected 18 patients at the National Institutes of Health hospital in Bethesda, Md., one of the nation’s premier medical research institutions. Six of the patients died that year; a seventh succumbed in 2012. The CDC says the organism is particularly dangerous because it can transfer its drug-resistant properties to other bacteria, making them immune to treatment as well. And it kills up to half the patients it infects.
The NIH outbreak put area hospitals on notice to be on the lookout for drug-resistant organisms among the patients they serve, and what they found was not encouraging. A survey by health officials in Maryland found that 80 percent of acute care hospitals in the state had at least one patient who was either carrying or infected with a drug-resistant strain of bacteria similar to the one found in the NIH victims. Those data were particularly disturbing because they seemed to suggest that the normal safeguards recommended by the CDC to prevent transmission of infectious agents may not be sufficient to confine the bacteria.
Even before the NIH outbreak, officials had been aware of the danger posed by drug-resistant organisms that are passed among patients by hospital personnel and equipment. At the Johns Hopkins Hospital, for example, physicians are instructed to thoroughly wash their hands before and after touching every patient, and the hospital goes to great lengths to ensure not only that patients’ rooms are cleaned and disinfected when they leave but that every medical device and piece of equipment used in their care is sterilized before coming into contact with another patient. The list includes everything from ventilator machines to surgical instruments to the blood pressure cuffs and oxygen monitors at patients’ bedsides.
Staff epidemiologists also scrutinize the vectors along which infectious agents are transmitted, such as the surfaces in examination rooms and offices. Many emerging drug-resistant bacteria are inherently hardy and have adapted to survive for long periods if they establish themselves in some favorable environmental niche. At the NIH, organisms hiding in the plumbing system forced officials to replace dozens of sinks and drains. Hopkins recently began using pairs of mechanical robots that clean patients’ rooms by misting them with concentrated hydrogen peroxide, then releasing a catalyst that turns the chemical into water and bathes all the exposed surfaces with disinfectant.
Hospitals are also limiting the use of antibiotics. Using only the right antibiotic at the right time and in the right dose can help prevent the emergence of new strains of drug-resistant germs. Otherwise, the bacteria adapt by developing resistance to the drugs, which is how we got into a situation where there are no good treatment options for some kinds of infections. Similarly, hospitals are trying to limit the duration of invasive procedures and devices, like ventilators or catheters, that put patients at high risk of infection.
The precautions hospitals have been taking before and since the 2011 outbreak of Klebsiella at the NIH are essential if we are to avoid a much more dangerous public health crisis, and they must be strengthened as drug-resistant strains of bacteria continue to evolve. It will take an extra level of vigilance to keep these highly lethal agents from spreading outside the hospitals where they are now mostly confined among the sickest patients, and it may be that the most officials can do is slow the process down.
We still need to develop more effective new antibiotics and treatments to keep up with the emergence of resistance, and even if we do everything right the battle between humans and bacteria is likely to remain an ongoing concern. But our future will be a lot scarier if we fail to heed the danger before lethal microbes become more common and spread to people with routine illnesses.