September 26, 2013
Less Reliance On Antibiotics Can Prevent Dangerous Superbug Illness
Brett Smith for redOrbit.com - Your Universe Online
Public health officials have been calling for the more judicious use of antibiotics for years and a new study from UK researchers has indicated that using fewer antibiotics can help prevent illness from an antibiotic-resistant ‘superbug’ known as Clostridium difficile.
One of the more feared superbugs, known to spread in a hospital environment, C. difficile causes severe diarrhea, cramps and could lead to life-threatening complications. A vigorous cleansing campaign among UK hospitals has only been met with limited success and a new strategy to combat the bacteria is necessary, according to the authors' paper, which was recently published in the New England Journal of Medicine.
For over three years, study researchers tracked every known case of C. difficile in Oxfordshire, a county located northwest of London. The team’s analysis found that less than a fifth of cases had been spread between hospital patients. The researchers also found that the number of cases fell over the course of the study, from 2008 to 2011.
"This is a landmark study in understanding how patients with C. diff are linked,” said study author Mark Wilcox, a microbiology expert at the University of Leeds. "The results have an important message for infection teams. Continuing on the same path to controlling C.diff will not ensure that all preventable cases are avoided. New measures are needed to prevent this bug spreading and being provoked to cause infection."
“We must be clear, good infection control measures have helped minimize transmission rates in hospitals,” added study author Tim Peto, a professor of infectious diseases at the University of Oxford. "However, what our study has shown is the vast majority of cases were not caught from other hospital cases, and the total number of cases has fallen, so other factors, in addition to hospital infection control, must be at work."
He added that the antibiotic nature of C. difficile is the “key” to its proliferation.
"People usually become ill with C. diff after taking antibiotics, because antibiotics don't just kill "bad" bugs but also "good" bugs in the gut, allowing the resistant C. diff to take over,” explained co-author David Eyre, a microbiologist at the University of Oxford. “One explanation for all types of C. diff going down is that using antibiotics more carefully can prevent people becoming ill with C. diff even if they are exposed to it.”
"Our study indicates that restricting the use of antibiotics may be more effective in reducing the number people who fall ill with C.diff than lowering transmission rates through infection control measures,” he added.
After performing a genetic comparison between C. difficile cases, the researchers revealed those cases that were matched and therefore most likely connected. Using hospital records and the community movements related to each case, the scientists determined whether transmission was likely to have happened due to hospital or patient contact.
They discovered that 35 percent of cases were so close genetically, they were probably caused by direct transmission. Out of that group, 55 percent were connected by hospital contact. In total, only 19 percent of all cases could be connected to hospital transmission from other sick patients with C. difficile.
"Additionally, 45 per cent of all cases were so different that they could not have come from another sick C.diff patient in Oxfordshire,” Peto said. “These results suggest that there is a large, unknown reservoir of C.diff bugs that can cause infection and more work needs to be done to identify these sources.”