A new strain of the norovirus stomach bug that has hit New Zealand has been linked to a death in Northland.
The Sydney 2012 norovirus strain, identified in Sydney last year, is a combination of two strains that originated in Holland and Japan in about 2007. Northland Medical Officer of Health Dr Jonathan Jarman said it was a new, highly infectious strain that could cause epidemics.
It had health officials around the world concerned, and 17 cases of the new strain had already been identified in New Zealand. One of those victims had died.
Dr Jarman said the new strain had replaced the New Orleans strain that had been around since 2009. All five confirmed Sydney strain norovirus cases reported in Northland between September and December were in rest homes, affecting residents and staff. The deceased had been a rest home patient.
There were 84 outbreaks of the new strain nationally between October and December, and a total of 177 norovirus cases in Northland last year. The UK reported more than a million cases of the new strain last year.
"The feedback I have received from rest home nurses is that the Sydney 2012 strain is similar to the New Orleans strain but perhaps causes more vomiting," Dr Jarman said.
It was likely that many more people had been affected than just those who had been confirmed, however, because those who were otherwise healthy suffered only a couple of days' illness, and would not be tested.
There had been two deaths in Northland in 2011 that were associated with outbreaks caused of the New Orleans 2009 strain, so one death from the new strain was not out of the ordinary.
"Norovirus gastroenteritis is normally only a mild to moderate illness, but the elderly and the very young can have more serious disease," Dr Jarman added.
"In 2011 we had a large outbreak of norovirus in Northland rest homes. The final number of affected people with confirmed or suspected norovirus gastroenteritis was 288, with two associated deaths."
One of the unique features of norovirus was that it could spread through the air as well as the usual ways of tummy bugs. It had been described as the Ferrari of the virus world because it was so infectious and could spread so quickly.
"I take my hat off to any rest home that can control an outbreak of norovirus," he said.
The main symptoms were vomiting and diarrhoea, stomach pains, aching muscles, feeling off-colour and a headache that usually lasted for a couple of days. Anyone with such symptoms was advised to stay away from other people and see a doctor if the symptoms were severe or the illness did not ease after two days.
There was no treatment for norovirus other than to let it take its course and stay hydrated by drinking regularly. The best means of preventing its spread was thorough hand hygiene after going to the toilet and before preparing food.