Norovirus alert despite official end of outbreak

The norovirus outbreak that hit six Northland rest homes and was linked to the deaths of two elderly residents is now officially over.
The outbreak of the highly infectious disease affected 288 people in six Northland rest homes since starting at Jane Mander Retirement Village in late April.
Puriri Court Rest Home and Hospital, Parahaki Court Rest Home, Kamo Home and Village, Radius Baycare Home and Hospital and Shalom Aged Care were also affected by the bug, but Northland Medical Officer of Health Jonathan Jarman says all are now free of norovirus.
Dr Jarman said the two rest home resident deaths had norovirus listed as an antecedent cause of death - that is, it was not the cause of death but it was linked to the cause of death.
But while the outbreak is officially over in the rest homes, high traces of norovirus have been found in the upper Whangarei Harbour, which has been closed for shellfish gathering until the end of the month.
Health officials are concerned that people eating contaminated shellfish from the harbour, upstream of a line from the Onerahi yacht Club to Portland, could become infected with norovirus.
"High levels of norovirus are to be expected in sewage during community-wide outbreaks of the disease," Dr Jarman said.
He suspects the harbour infection occurred through sewage overflows during heavy rains on May 2.
The rest home deaths - which were the result of outbreaks of the bug in the community - had nothing to do with the norovirus found in the harbour, Dr Jarman said.
Norovirus is a mild to moderate illness, but the elderly and the very young can be affected more seriously. The most usual ways of catching it are contact with infected people, eating contaminated food (especially shellfish), or drinking untreated water.
Meanwhile, Whangarei District Council infrastructure and services manager Simon Weston has reinforced that no one has become ill or died because of harbour pollution.
"On May 2 we had very heavy rain and waste water overflowed into the harbour, raising levels of the virus in the upper harbour in the days following the spill," Mr Weston said.
"The notion that people caught the disease from the harbour water is incorrect, as pointed out by the medical officer of health.
"This mix-up has been upsetting and distressing for the community and has caused significant concern, so I am very glad the medical officer of health has clarified that point - the disease was in the community and was introduced into the wastewater system, and then into the harbour during the heavy rain. It didn't go from the harbour into the community.
"A new Hatea pump station storage and treatment tank is being constructed right now. In future rainfall events of a similar size to the May 2 storm it will have the capacity to store or treat the volume of waste water that overflowed from the station on May 2."