'Superbugs' That Strike the Sickest Patients

....While they don't cause disease in healthy people, infections by gram-negative bacteria can be devastating for those with weak immune systems: wounded soldiers, burn victims, cancer and AIDS patients, the elderly, premature infants and those with severe injuries or illnesses. The gram-negative bugs that pose the biggest threat include acinetobacter baumannii, enterobacter aerogenes, and pseudomonas aeruginosa, which can attack through wounds, surgical incisions, central lines, respirators and catheters.

Most worrisome, says Centers for Disease Control and Prevention epidemiologist Arjun Srinivasan, is that bacteria like acinetobacter are becoming resistant to the class of drugs known as carbapenems, considered a last line of defense for gram-negative organisms.

....Hospitals are struggling to determine how best to detect the presence of different types of bacteria and identify patients on admission who might carry them on their skin or in their intestinal tract. Such screening programs can be costly, and it isn't clear who will pay for them. "You can't culture every patient in every bed for every possible resistant organism," says Gina Pugliese, vice president of the safety institute at Premier Inc., a large hospital purchasing cooperative.

Hospitals are launching myriad new efforts to combat the bugs: They are sterilizing equipment with techniques including vaporized hydrogen peroxide that can decontaminate equipment without harm, discarding contaminated devices, bathing ICU patients with a chemical antiseptic and closing down units for decontamination. They are also requiring hospital workers to wear protective equipment when caring for infected patients or those considered at risk for infection, draping patients from head to toe during procedures and isolating infected patients.

The measures can be hard on patients and families, especially those placed in isolation, says Pat Rosenbaum, a nurse who is authoring new guidelines from the Association of Professionals in Infection Control and Epidemiology for the prevention of acinetobacter infections, to be released next year. "We don't take lightly putting people into these kind of precautions, but we also don't want to take a risk that they might infect others," she says.

....Infectious-disease experts say the most worrisome of the gram-negative bacteria may be acinetobacter, which is commonly found in soil and water, and may be carried by up to 40% of people on their skin. Over the past several years, a virulent strain has developed increasing resistance to antibiotics. This strain survives in hospitals for long periods and targets severely ill patients through the skin and airways, causing pneumonia and infections in the skin, tissue, central nervous system and bones. There have been a growing number of infections in wounded military personnel returning from Iraq and Afghanistan, where the bacteria thrive in the soil of the hot, humid climates.

Johns Hopkins learned the hard way how quickly acinetobacter can spread....

...."We seem to be out of bullets for these multi-drug-resistant organisms, so we have to find ways to control and prevent these infections, because once your family starts down that path it is a black hole," says Mr. Nahum.

An Emerging Threat

Gram-negative bacteria, harmless to the healthy, are fast developing resistance to antibiotics and infecting the sickest patients.