Genome sequencing halts superbug outbreak

By Kate Kelland ReutersResearchers have used DNA sequencing for the first time to identify, analyze and put a halt to an infectious disease outbreak in a hospital.

The success of the technique, which used fast genome sequencing technology to control an outbreak of the MRSA superbug on a baby ward, suggests it could be used to control hospital bugs, salmonella and E.coli infections and diseases like tuberculosis, scientists said.

"What we have glimpsed through this pioneering study is a future in which new sequencing methods will help us to identify, manage and stop hospital outbreaks," said Nick Brown, an infection control doctor at Addenbrooke's Hospital Cambridge, who co-led the study and presented the findings at a briefing.

MRSA, or methicillin-resistant staphylococcus aureus, is a drug-resistant bacterial infection, or superbug, and a serious public health problem. When outbreaks occur in hospitals it can lead to the closure of whole wards with many people infected.

The bug kills an estimated 19,000 people in the United States per year. Although rates of MRSA infection have come down significantly in Britain in recent years, it still presents a major threat with several hundred deaths a year and high hospital costs involved in managing infected patients.

Julian Parkhill from Britain's Sanger Institute, who also worked on the study, said there is a "real health and cost burden from hospital outbreaks" which could be significantly reduced or eliminated if they were contained swiftly.

In the study, staff at Addenbrooke's hospital using routine screening over a six month period found 12 patients carrying MRSA. Because they were only using standard tests, which provide limited information, the infection control team was not able to tell if the 12 were part of an outbreak, or were unconnected cases that did not present a threat.

MRSA is a bug present in around one percent of the population at any time, and does not always cause infection.

Parkhill and Brown's team analyzed MRSA samples from the 12 patients with DNA sequencing technology and found that all the MRSA bacteria were closely related, confirming an outbreak.

By tracing relatives and other people who had recent links to the hospital, they also found the outbreak was more extensive than previously thought, with twice as many people carrying or infected with the MRSA strain.

Excerpt from:
Genome sequencing halts superbug outbreak