Patients in intensive care wards at most risk from hospital superbugs

Patients in intensive care wards are particularly at risk of infection from so-called superbugs, a study has found.

Patients in intensive care wards are particularly at risk of infection from so-called superbugs, a study has found.

Scientists in Sweden warned of an "unexpectedly high" level of transmission of bacteria between intensive care patients. Many of the bugs were resistant to several antibiotics. Often it appeared to be ventilation equipment itself that was spreading the bacteria.

The researchers found that 70 per cent of those they studied were colonised with bugs caught from other patients in their unit. They wrote in the journal Critical Care: "Although transmission of bacteria does not necessarily lead to infection, it is nevertheless an indication that infection control measures can be improved."

The study focused on 20 intensive care patients at Huddinge University Hospital, in Stockholm. All had required mechanical ventilation for at least three days. A team led by Professor Charlotta Edlund, from the Karolinska Institute, took swabs from the patients' airways and analysed the genetic fingerprints of bacteria grown from them. By seeing which patients had harboured the same strains it was possible to trace the transmissionpatterns.

The scientists investigated the transmission of several strains of Staphylococcus bacteria, called CoNS. These are the third most common cause of hospital infections.

Seventeen of the patients were colonised by CoNS during their hospital stay. In six cases, the bacteria had colonised the lower airways after the patient was ventilated - suggesting that the procedure itself had introduced the bacteria. A total of 14 individuals had either passed on a bacterial strain to another patient, or received one from another patient. In one case, bacteria appeared to have passed from one patient to another who was only admitted after the first was discharged. This implied that the bugs had survived in the ward either on staff or other patients.

Many of the bacteria were resistant to a variety of antibiotics. A total of 21 per cent of the strains were resistant to six antibiotics, 34 per cent to at least five, and 59 per cent to at least four.Of the antibiotics, 95 per cent of bacteria were resistant to penicillin, but none was resistant to vancomycin, the "last resort" antibiotic used to treat the superbug MRSA.

"Guidelines for antibiotic use, close co-operation with infectious diseases specialists and restrictions with invasive treatment are strategies that can improve infection control and lower the incidence of hospital infections. Hand hygiene among staff is also an important factor," the scientists said in the report.