Northland District Health Board is defending itself against claims it kept quiet for six months rather than warn the public about a potentially super-strain of meningococcal disease.

Since an in-house memo was sent to hospital staff warning them to be vigilant as fatal meningitis cases could start to come in, three Northland people have died.

The memo - sent out by the board's microbiologist David Hammer in May - went as far as warning staff to get their own young children immunised with one of the newer vaccines.

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But no general health messages were made, enabling the public to also prepare against a killer disease that could be knocking on Northland's door.

The memo told medical staff that in one week two patients in unrelated cases had what was thought to be the virulent meningococcal strain called MenW or W ST-11.

There had been a ''significant rise'' in meningococcus W ST-11 cases across New Zealand, the memo said.

''As meningococcal disease peaks in the winter, I suspect that we will be seeing a whole lot more cases soon.''

Hammer's memo noted doctor-patient conduct carried a low risk of infection, but the disease tended to ''spread rapidly through areas where younger people congregate, such as schools, hostels, army barracks and university campuses''.

It wasn't until media coverage of the death of 16-year-old Kerikeri youth Dion Hodder, who died in Auckland City Hospital in October, the public became aware meningitis was doing the rounds. To date, there have been seven cases of MenW in Northland, including the three deaths.

On Tuesday this week, the Ministry of Health (MoH) issued warnings to GPs, health clinics, hospitals and the general public about MenW (W ST-11), with advice on what signs to watch for. The MoH said Northland had been worst affected to date.

The NDHB released its own public message on the same day. But the board has now hit back over criticism about it not having warned the public back in May.


The board said it had not wanted to alarm people, nor was it certain at the time if the cases were the MenW strain.

''It is truly tragic that three people in Northland have lost their lives to this dangerous disease, however we question the assertions that we should have warned the public earlier,'' a spokesperson said in a press release issued yesterday.

''In May we had two unrelated adult cases of MenW which warranted close monitoring. Without definite information it was not appropriate to alarm the community. This is a new strain of meningococcus that can present looking like any form of infection and appears randomly for no apparent reason.''

The spokesperson said, ''Dr Hammer proactively raised awareness amongst both GPs and secondary care clinicians asking them to be vigilant because the presentation of meningococcus tends to be more atypical than that of other strains.

''We have continued surveillance and monitored the disease incidence [and] we are in the process of reviewing some historical epidemiological data on invasive meningococcal disease in the hope that this will inform future decisions about our response.''

Despite the board's cautionary statement that MenW can have atypical symptoms, according to other public health information sources including MoH the medical wisdom and advice to parents or anyone else is ''take no chances - and act quickly''.

Meningococcal disease mimics flu-like symptoms although can include a rash, but worsens very quickly. Urgent medical attention is advised, and patients usually respond well to antibiotic treatments.