A norovirus outbreak has hit Rotorua Hospital and medical authorities are investigating whether the infection has spread to a rest home.
Lakes District Health Board infection control nurse Waverley Newson said three patients and 13 staff at Rotorua Hospital had been infected with the highly contagious illness during the outbreak between September 18 and 21.
The patients with diarrhoea and vomiting were cared for in a single room with an en suite, where available, and unwell staff were sent home. The hospital would not say which wards were affected.
Staff wore gloves and gowns and washed their hands regularly to prevent spreading the disease to other patients and environments.
Unwell staff were required to stay off work until 48 hours after their symptoms had gone.
"Although there is not an ongoing outbreak within Rotorua Hospital we are aware that a few staff have had diarrhoea and vomiting and this is expected due to the presence of norovirus in the wider community," Mrs Newson said.
Affected staff had described nausea, stomach cramps, vomiting and diarrhoea that lasted for one to two days.
One patient was admitted with dehydration because of the illness.
Norovirus outbreaks have also been reported in recent weeks in Tauranga, Gisborne, Auckland and Northland.
Mrs Newson said Rotorua staff were watching closely for anyone with symptoms.
Meanwhile, Bay of Plenty medical officer of health Dr Phil Shoemack said five residents had fallen ill at Cantabria Rest Home and Hospital since last week, four with diarrhoea and one with vomiting.
Medical authorities were still to confirm whether the residents had norovirus and a specimen had been sent away for testing.
The results of those tests were not expected to be available for at least a week.
However, there had been no more cases reported in the past 48 hours.
"Norovirus is so infectious we wouldn't expect an outbreak in a rest home to be so contained.
"I wouldn't be surprised if it's something less infectious."
Dr Shoemack said there were standard procedures for healthcare facilities to follow to contain such illnesses, which including keeping those infected in the same area away from those not infected and restricting visitors.
Cantabria Rest Home and Hospital manager Ruth Johnston did not want to comment.
Symptoms of norovirus included diarrhoea and vomiting, abdominal cramps, headaches, lethargy and fever, which can last 12 to 36 hours, but typically 24 hours.
Anyone with symptoms should contact their GP as every effort needed to be made to keep people away from general hospitals to avoid the spread of the illness.