A gastroenteritis outbreak in the Western Bay has seen an influx of people seeking medical treatment at Tauranga Hospital emergency department.
The ED has dealt with 100 gastroenteritis cases since Christmas Eve, clinical director Derek Sage said.
Gastroenteritis is an inflammation of the stomach and intestines from bacterial toxins or viral infection, often resulting in vomiting and diarrhoea.
About 10 per cent of people, mostly elderly, required intravenous fluids due to dehydration and 1 per cent, mostly children, were admitted to hospital.
However, most cases that arrived in the emergency department did not require hospital-level care and could have been managed by a GP or after-hours primary care, Dr Sage said.
He said the number of cases was not unusual for the time of year.
Dr Sage said that despite the hospital's infection control measures, gastroenteritis sufferers represented a potential infection threat to the hospital and the staff, so it was ideal to keep such cases out of the ED unless they were dehydrated and needing intravenous fluids.
Bethlehem Pharmacy's Mark Arundel said while there were plenty of people seeking their help for gastroenteritis problems over the New Year period, there had only been a couple this week.
"If anything, our perception is that it's moving through."
Mr Arundel said children and the elderly were most vulnerable to dehydration from gastroenteritis and needed to seek medical help quickly.
If people were sick for longer than two to three days, they should visit their doctor to ensure they did not have a more serious or reportable illness like giardia or salmonella poisoning, he said.
Mr Arundel said typical fix-it remedies such as drinking a glass of flat lemonade actually did more damage than good because it overloaded the person's already fatigued system with sugar, which caused further dehydration.
He recommended sachets that were specifically designed to replace fluids and electrolytes when diluted with water.
"The important message for people is if they do get sick, stay away from other people, hand washing is key, and rehydrate.
"The most common causes of gastroenteritis cases are actually from fecal bacteria, from poor hygiene. In other areas, gastroenteritis can be spread by coughing and touching.
"These things seem to be a bit more violent than when we were kids, when they were 24-hour bugs. Now they seem to be 72 hours."
A 24-year-old Mount Maunganui woman who still has the bug after 11 days said she initially thought it was heat stroke because it started with a fever and cold sweats. But then painful stomach cramps, diarrhoea and vomiting kicked in.
"It got so bad that I was waking up four to five times a night, having to rush to the toilet," she said.
Her only relief was lying in a fetal position. She was unable to eat or drink for three days and the illness ruined her out-of-town New Year celebrations because she spent most of her days in bed, she said.
"The doctor said there was a bug spreading around at the moment. I was prescribed painkillers and medication to ease my stomach cramps."
The woman said her flatmate was suffering the same symptoms.
A Toi Te Ora Public Health Service spokeswoman said they had received notifications of gastroenteritis and said if people were concerned, to contact their GP or call the Healthline number 0800 611 116.
However, if there were a cluster of people who had become ill after an event or gathering, they were asked to contact the Public Health Protection officer on 0800 221 555 and choose option 7 in case of potential norovirus or salmonella incidences.