Documents obtained by the Herald on Sunday under the Official Information Act reveal the outbreak was believed to have illustrated a flaw in the Ministry of Health's National Health Emergency Plans' focus on single major health events, but not situations that evolved over time, such the CRO incident.
"The incidence of CRO has highlighted a weakness in the Emergency Plan which focuses on mass casualty disaster, not a 'slow creep' disaster which is currently being experienced," minutes from meetings between the Ministry and Counties Manukau DHB state.
National Health Emergency Plans are documents prepared by the Ministry that provide DHBs and other health and disability organisations with information about how to prepare for and respond to health-related emergencies such as a pandemic.
Read more: Spike in drug-resistant infections forces National Burns Centre at Middlemore to limit admissions
Internal documents and communications between Counties Manukau DHB and the Ministry of Health also said the source of the CRO outbreak was still unclear and may never be known.
However, more cases of CRO would certainly occur in New Zealand and the system needed to be prepared to cope with future infections.
"They are becoming more common across our community which means there may be patients in many parts of the hospital with CRO whose health is not compromised," Middlemore Hospital chief executive Dr Gloria Johnson wrote in a letter to all staff on February 6.
"Their CRO colonisation may be known at the time of admission, discovered subsequently, or not discovered at all, as only selected patients are tested for CRO colonisation."
Dr Stewart Jessamine, Ministry of Health director of protection, regulation and assurance, said the Ministry was reviewing the Multi-complex Burn Action Plan as part of an ongoing review of the National Health Emergency Plans.
"Initial discussions have begun and the review is expected to be completed in the 2018/19 year. The Ministry will continue to discuss any wider related issues with DHBs."
Dr Joshua Freeman, clinical director of microbiology at Canterbury DHB and an expert on CRO, told the Herald on Sunday New Zealand needed a screening system in hospitals similar to biosecurity at our borders.
"[CRO are] like a dangerous introduced pest. Just like we'd be concerned about economic impacts and MPI would be concerned, so the MOH would be concerned about the health impacts of this as it makes incursions in our hospitals," he said.
"The real concern is about these getting into the specialised units because if they get into our intensive care units, if they get into our cancer units like our haematology units, they'd just bring those units to their knees."
To prevent the spread of CRO, healthy carriers needed to be identified when they arrived at a hospital.
"If we identify those people then we can put in place additional special precautions to prevent it spreading further to the people. We can also help those people who are colonised to make sure they are treated appropriately," said Freeman.
Infections caused by CRO were becoming more prevalent overseas and could not be controlled, but restricting their spread could give New Zealand more time during which more preventative technologies might become available.
"Our planning for it should be a little bit like planning for the influenza pandemic. It is essentially a pandemic in slow motion."
What are CRO?
• Carbapenem resistant organisms (CRO) are bacteria, usually found in the gut, that have become resistant to antibiotics.
• They aren't usually dangerous to healthy people but can kill people who are vulnerable to infection.
• They can also infect healthy carriers if that person gets sick or has surgery.
• They are common overseas, particularly in India, but are rare in New Zealand.
• CRO often spread "silently" and are difficult to trace because carriers don't have any symptoms.