NZ at 'the very beginning' of superbug epidemic

The number of Kiwis carrying drug-resistant superbugs is set to double this year.

There have already been 34 cases of people with carbapenem-resistant organism (CRO) in 2018, compared to just 33 for all of 2017, according to figures from the Institute of Environmental Science and Research (ESR).

A decade ago, there were only on average six a year, and microbiologist Siouxsie Wiles says things are likely to get worse.

"We're just at the very beginning of it popping up here... the worry is that there have been 30 people already, and we're only in August."

CROs are a family of bacteria which have developed resistance to all but the strongest antibiotics currently available. They produce carbapenemase, which disables carbapenem antibiotics. If those drugs don't work, then doctors are required to use even stronger antibiotics.

"We call them the antibiotics of last resort, because they're really quite toxic. They're not very nice drugs at all," says Dr Wiles.

The AM Show Siouxsee Wiles
Siouxsee Wiles. Photo credit: The AM Show

The bugs are generally picked up overseas, usually in India, southeast Asia or the Pacific Islands. So far, none of the cases have resulted in untreatable infections.

"Most of the cases here are in people who pick up this bacteria overseas - generally if they've been hospitalised overseas they'll pick it up, and then they'll come in. A lot of the people who we found have it in New Zealand... they just are colonised with this bacteria. They don't have an infection, but [have the potential] to pass it on to somebody who's very sick."

The bugs can survive in "colonised" people's guts, throats and nose without causing any problems. But if drug-resistant bacteria end up in the bloodstream or the lungs, or anywhere else they're not meant to be, that's an infection and with present medicine, death usually follows.

Dr Wiles says there is a woeful lack of funding going towards antibiotic research, and we're about 30 years behind where we need to be.

"The thing that's frightening about them is they are able to share these resistant genes between them. When one of them becomes resistant to antibiotics, it can share that resistance around."

The ESR data backs that up. Some people screened were found to be carrying four or five different CROs - likely the result of horizontal gene transfer.

She says hospitals themselves become inoperable if it becomes an epidemic, as sick people are far more vulnerable to bacterial infection than the healthy.

Around 600 patients may have come into contact with a carrier at Middlemore Hospital earlier this year, and need to be tested to see if they picked anything up, according to Counties Manukau DHB.

While there have been a number of reported breakthroughs in treating hardy CROs, Dr Wiles says it can take years before drugs get out of the lab and into people.

She also says drug companies have little profit motive, because bacteria are likely to evolve resistance to whatever they come up with, rendering it useless.