A multidrug-resistant superbug that first appeared in 2007 spread through a Rhode Island hospital this year, infecting two patients and bringing the overall number of U.S. cases to 13, according to a new CDC report.
The superbug—carbapenem-resistant Enterobacteriaceae (CRE) containing New Delhi metallobeta-lactamase (NDM-1)—is sometimes called the "Indian superbug" and was first reported in a patient hospitalized in New Delhi in 2007.
Although transmission of NDM-1 was first linked to travel in south Asia, it has more recently become a problem across Europe, according to "Superbug" author and journalist Maryn McKenna.
The Rhode Island cases
In the new report, CDC details how two patients in Rhode Island were found to have a Klebsiella pneumoniae isolate containing NDM.
Last year, a Rhode Island resident travelled to Asia, where she was hospitalized in Vietnam in late December with spinal cord compression. Only a week later, on Jan. 6, she was hospitalized in Rhode Island, diagnosed with lymphoma, and began inpatient chemotherapy.
By February, she was exhibiting signs of highly resistant bacteria in her bladder. During that time, she was permitted limited movement outside of her room and was catherized. A CDC test on March 4 found that she was carrying CRE containing NDM-1, at which point the hospital isolated her in her room.
On March 30, CDC confirmed that a second patient treated in the same hematology/oncology unit as the first patient had the same strain of NDM-1.
According to the report, the two patients were not treated by the same physicians or nurse practitioners. In addition, they did not stay in the same room, either concurrently or subsequently.
CDC: A 'robust infection control effort is needed'
Marc Siegel, an infectious disease expert at NYU Langone Medical Center in New York City, told HealthDay that "this is not an epidemic, but it is eyebrow-raising." He adds that patients will likely import the bacteria from abroad and warns "we are going to be seeing more cases."
According to McKenna, the NDM-1 cases in Rhode Island are "probably predictable" but "very much not good." She notes that the bacterial species in which NDM-1 was identified survives on hard surfaces in hospital rooms, such as IV poles, bed rails, and computer keyboards. She also notes that NDM-1 is generally susceptible only to an older, toxic drug named colistin and a less-effective drug named tigecycline.
CDC notes that physicians treating CRE have "few, if any, therapeutic options." In an editorial note included with the report, the agency called for "a robust infection control effort… to limit or slow the spread of all CRE, including NDM-1, at the local, national, and international levels." Specifically, it stressed the importance of hand hygiene, contact precautions, and minimizing the use of invasive devices and antibiotics (CDC report, 6/22; McKenna, WiRED, 6/21; Reinberg, HealthDay, 6/21).