It could takes weeks or months to control a superbug outbreak at Christchurch Hospital

One ward has two outbreaks of Vancomycin-resistant enterococci - or VRE.

One has confirmed links to a larger Auckland cluster.

Health NZ's Dr Sarah Berger says the bacteria was first detected in Christchurch late September.

She says all current cases are linked - with confidence they're being brought under control.

She's expecting more frequent incursions of VRE in New Zealand, as it becomes more prevalent overseas.