A SEVERE bout of gastro is making its way through several Tamworth schools and workplaces, and health experts are urging people with symptoms to avoid aged and childcare facilities.
Hunter New England Health public health physician David Durrheim said the outbreak of gastro was most likely due to norovirus.
"That's usually the cause of winter-spring gastro," Dr Durrheim said.
"This is the season for it, and often that virus does cause a seasonal peak in cases.
"As we get into summer, other bacteria and often food-borne ones are the cause."
Dr Durrheim said norovirus was "highly infectious".
"It is one cause of diarrhoea and vomiting that can be caught by breathing in a contaminated confined space, like a toilet," he said.
"However, the most common way to catch it is by not washing your hands, and coming into contact with contaminated food or other people's hands.
"That's the way it is generally transmitted and you only need a small number of viruses to spread."
The symptoms include "quite dramatic" vomiting and diarrhoea, which can "rapidly lead to dehydration".
"The concern is around little children and the elderly, who have a more difficult time dealing with the effects of dehydration," Dr Durrheim said.
"That's why it's extremely important that, if you have any signs of symptoms, not to visit high-risk groups like hospitals, aged cares or childcares.
"Outbreaks in these environments can more readily occur, with devastating consequences."
Symptoms of viral gastro usually last between one and three days, but sometimes longer. Any baby less than six months old who has gastro should be taken to a GP or local emergency department immediately.
"It's also important not to prepare food or go swimming for at least 48 hours after symptoms disappear," Dr Durrheim said.