"Genomic data can identify unexpected modes of transmission," Dr. Segre said. "Though the transmission path is difficult to detect, the genomic data is indisputable."
When combined with the traditional epidemiology tracking data, the genome sequence results showed that Patient 1 transmitted the bacteria to other patients on two separate occasions from infections on different parts of her body, creating two major clusters of infected patients.
Even as the epidemiologic and genomic investigation proceeded, the infection-control team in the NIH Clinical Center employed increasingly intensive strategies to stop the infection from spreading. For example, they used a vapor of hydrogen peroxide to sanitize rooms and removed sinks and drains where K. pneumoniae had been detected. They also limited the activities of hospital staff and the use of equipment exposed to infected patients so the microbe could not spread to uninfected patients.
In addition, the NIH doctors treated the first patient's infection with colistin, an older, toxic antibiotic considered a drug of last resort. Fortunately, the treatment worked and the patient recovered.
The infection-control interventions proved successful, and by the end of the year, no new cases arose in the Clinical Center, stemming the outbreak.
"Genome sequencing and analysis is our best hope for anticipating and outpacing the pathogenic evolution of infectious agents," said Dr. Segre. "Though our practice of genomics did not change the way patients were treated in this outbreak, it did change the way the hospital practiced infection control."
"This study makes it clear that genome sequencing, as it becomes more affordable and rapid, will become a critical tool for health
|Contact: Raymond MacDougall|
NIH/National Human Genome Research Institute