Threat of fatal superbug grows worse every year

Photo / Sarah Ivey

The threat of a potentially fatal superbug is growing, and infection control officials cannot see any let-up.

Incidences of ESBLs, which include E.coli, are increasing by nearly half every year, with northern and southern Auckland areas the worst affected.

ESBLs typically "colonise" the bowel, harmlessly, but can cause difficult infections that are costly to treat when they cross into the urinary tract.

They destroy many common oral antibiotics and often must be treated with expensive ones given intravenously. This can add seven days to a hospital stay.

ESBLs - E.coli and klebsiella are the commonest species - can also cause infections in joints, wounds and the bloodstream. Occasionally they are fatal.

Middlemore Hospital, run by the Counties Manukau District Health Board, is recovering from an 11-month ESBL outbreak in its ward number 33.

North Shore Hospital, run by the Waitemata DHB, has struggled to control ESBLs since 2007, but officials believe they are winning.

"It's ongoing," said Waitemata's nursing director Jocelyn Peach, "but we've now got it down to the point where it's no longer a big issue.

"We're about to say we haven't got an outbreak any more."

New Zealand's rate of new ESBL cases rose by 43 per cent in 2009 - the latest estimate - after rising by a similar percentage each year since mid-decade.

Dr Peach and colleagues at Middlemore said there was no reason to expect the increase last year was any smaller.

She said problems with multi-resistant hospital superbugs were now permanent.

"We just have to get really clever in how we manage prevention - hand hygiene and so on - and deal with outbreaks."

Waitemata had 1635 patients last year who tested positive for ESBL. Most of the cases were at North Shore Hospital, but a few were at Waitakere Hospital.

Fifty-seven per cent acquired the bug in hospital, down from 70 per cent in 2009.

From April to August 2009, five elderly North Shore Hospital patients who had a variety of illnesses died with ESBL, although it was not the cause of their deaths.

It is estimated that more than 10 per cent of the affected patients last year became sick with an ESBL infection. None died.

Waitemata screens virtually all hospital patients for ESBL and puts those with the bug in the same ward.

At Middlemore mainly only high-risk patients are screened. During its January-to-November outbreak last year, staff screened patients admitted to or discharged from ward 33.

Middlemore recorded 541 ESBL-positive patients during the outbreak period who had been "colonised" in the community, and 80 who picked up the bug while on ward 33, plus a few others who also acquired the bacteria in the hospital.

Only one patient had an infection - of the urinary tract - and that person was successfully treated.

North Shore and Middlemore have made big efforts to improve hygiene - such as putting alcohol-based hand gel on or near every bed, running campaigns to encourage staff to improve their hand hygiene, and introducing special cleaning regimes.

North Shore reports that the percentage of staff cleaning their hands every time they should has increased from 40-50 per cent, to 65 per cent now, while Middlemore says its latest formal check shows its rate has slipped to 73 per cent from 77.

WHAT ARE ESBLs?

Extended-spectrum beta lactamase-producing bacteria (ESBLs) are a group of bacteria that include E.coli.

INFECTION RATES PER 100,000 POPULATION:

* Waitemata DHB area - 533.7
* Counties Manukau - 513.2
* Auckland - 245.9
* Hawkes Bay - around 170
* All others were far lower.