11 December 2018

Your gut may be to blame for your bloodstream infection picked up in hospital

Researchers have found that bloodstream infections mostly start in patients' own bodies – often in the large intestine.

Bloodstream infections contracted during a hospital stay are usually caused by a patient's own digestive tract, not a doctor's dirty hands or another patient's cough, a small new study suggests.

Stanford University researchers used new computer software to quickly identify the source of bloodstream infections among 30 patients. The findings showed that the infections mostly started in patients' own bodies – often in the large intestine.

Treating the source of the infection

Being able to trace these infections to their source, rather than guessing, is a big step toward addressing the risk factors, said Dr Ami Bhatt, an assistant professor of haematology and genetics at Stanford.

"Until now, we couldn't pinpoint those sources with high confidence," Bhatt said in a university news release. "That's a problem because when a patient has a bloodstream infection, it's not enough simply to administer broad-spectrum antibiotics. You need to treat the source, or the infection will come back."

The new programme could help doctors rapidly learn if the germ responsible for a bloodstream infection came from a break in the skin, leaked through the intestinal wall, or was on the surface of a catheter or bed rail. This, in turn, would mean better steps toward eradicating the infection, she said.

Bhatt's team focused on the gut for the study because it's the home of 1 000 to 2 000 different germs.

These bugs usually don't cause any problem, Bhatt said. "They're perfectly well-behaved in the gut. It's only when they show up in the wrong place – due, for example, to leaking through a disrupted intestinal barrier into the bloodstream – that they cause trouble," she explained.

Infections not 'passed around' as much

In the study, the researchers analysed blood and stool samples from patients who developed bloodstream infections when they had bone-marrow transplants between October 2015 and June 2017 at Stanford Hospital. In addition, each patient's entire gene sequence was also analysed.

The researchers didn't find much evidence that any patient's bloodstream germ matched strains in other patients' blood or stool.

"I don't think we're passing around active infections among one another as often as has been assumed," Bhatt said.

The report was published online in the journal Nature Medicine.

Image credit: iStock


Live healthier

Lifestyle »

E-cigarettes: Here are five things to know

E-cigarettes have become hugely popular in the past decade, but a rash of vaping-linked deaths and illnesses in the US is feeding caution about a product that's already banned in some places.

Allergy »

Ditch the itch: Researchers find new drug to fight hives

A new drug works by targeting an immune system antibody called immunoglobulin E, which is responsible for the allergic reaction that causes hives.