Superbug infection risk increases with length of hospital stay

Date: Sep-08-2014Superbugs - bacteria that do not respond to many of the drugs designed to treat them - are an increasing problem, particularly in hospitals. Now, a new study presented at a meeting in

the US suggests if a patient develops an infection while staying in a hospital, the chances of

that infection becoming drug-resistant increase with each extra day spent in the

hospital.

Researchers at the Medical University of South Carolina (MUSC) analyzed historical data from

their academic medical center of 949 cases of patients who had acquired gram-negative infections

during hospitalization.

They found if a patient acquires a gram-negative infection while staying in the hospital, the

chances of that infection being multidrug-resistant goes up by 1% for each day of

hospitalization.

The team presented their findings at the 54th Interscience Conference on Antimicrobial Agents

and Chemotherapy (ICAAC) that is being held in Washington, DC, from September 5-9, 2014.

Gram-negative bacteria becoming increasingly resistant to antibiotics

According to the US Centers for Disease Control and Prevention (CDC), gram-negative bacteria

are a particular problem in acute health care - they cause wound or surgical site infections,

pneumonia, blood infections, meningitis and other serious conditions. They are resistant to

several drugs and are becoming increasingly resistant to most available antibiotics.

The chances of a patient's gram-negative infection becoming multidrug-resistant goes up by 1% for each day of hospitalization, according to the latest study.

Gram-negative bacteria are able to adapt and find new ways to be drug-resistant; they can

swap genetic material with each other, thus passing on drug-resistance to other bacteria.

Hospital-acquired infections are responsible for a large proportion of hospital-related

deaths, and rates are rising, say the MUSC researchers.

On any given day, they note, about 1 in 25 patients in hospitals have at least one hospital-acquired infection, of which around 1 in 3 is caused by gram-negative bacteria.

But there is currently not enough information on how many infections and deaths are due to

gram-negative bacteria. The CDC

estimate that in the US in 2011, approximately 75,000 deaths occurred in around 722,000 patients

with hospital-acquired infections. More than half of the deaths occurred outside of the

intensive care unit.

Risk of gram-negative infection being drug-resistant increases by 1% for each day in

hospital

In their study, the MUSC researchers found in the first few days of hospitalization, about

20% of infections are associated with multidrug-resistant gram-negative bacteria. This proportion

rises steadily for the first 4 or 5 days, and then jumps dramatically to over 35% at 10

days.

Looking at the data statistically, the team suggests this means the risk of a gram-negative

infection becoming drug-resistant during a hospital stay increases by about 1% for each day in

the hospital.

John Bosso, one of the study authors and professor in pharmacy at MUSC, says:

"Our findings emphasize one of the risks of being in the hospital, acquiring a multidrug-resistant infection. At the very least, this observation argues against both unnecessary

hospitalization and unnecessarily long hospitalization."

He and his team also discovered that the chances of acquiring a drug-resistant infection in

the hospital appears to vary from superbug to superbug. This information could be important for

doctors and clinicians hoping to reduce rates of hospital-acquired infections, says Prof.

Bosso.

Meanwhile, in June 2014, Medical News Today learned how a group of UK researchers

discovered a possible way to stop drug resistance in

bacteria. The team hopes the study, which explores how superbugs build their defenses, may

lead to new drugs that the bacteria cannot become resistant to.

Written by Catharine Paddock PhD

View all articles written by Catharine, or follow her on:

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.