Victorian parents have been urged to keep their sick kids at home due to a spike in contagious gastroenteritis cases at childcare centres.

There have been 246 gastro outbreaks at childcare centres this year, which according to the Health Department, is more than four times higher than the five-year average.

Victoria's executive director for communicable disease Bruce Bolam said the bug is highly infectious, with symptoms including nausea, vomiting, diarrhoea, abdominal pain, fever and muscle aches.

Anyone who is sick, but particularly children, should stay home for at least 48 hours after symptoms subside.

Those living in a household with someone who has gastro should also avoiding visiting high-risk facilities such as hospitals, aged care facilities and childcare centres.

"Gastroenteritis can spread quickly through settings such as childcare centres, where children play and interact closely with each other and can readily spread their bugs," Dr Bolam said in a statement on Wednesday.

He some illnesses such as gastro had been relatively dormant over the last year but had increased in prevalence as restrictions eased.

NSW and the ACT have also issued public health alerts due to gastro outbreaks in recent months.

"Handwashing with soap and water is still the best personal hygiene method to minimise the chance of spreading the virus," Dr Bolam said.

He noted that alcohol-based sanitisers are not very effective against bugs such as norovirus, which is the predominant cause of the current childcare outbreaks.