The Victorian Department of Health and Human Services was notified of an outbreak at Bentley's Aged Care about December 11.

City of Greater Bendigo staff are believed to have been informed and to have attended about the same time.

It is not yet known how many residents at the 57-room home on Harpin Street have had gastro.

The Department of Health and Human Services has been notified of about 330 outbreaks in care facilities so far this year.

Facilities are not legally required to notify the department of viral gastro outbreaks, though a spokesperson said it was 'strongly recommended'.

They said the department had been working with Bentley's Aged Care and the City of Greater Bendigo to manage the outbreak.

Symptoms of gastro include diarrhoea and vomiting.

A sign at the home's entrance said it was closed to all visitors until further notice because of gastro.

"An outbreak is considered over when the facility has been symptom-free for 48 hours," a department spokesperson said.

"Due to the nature of the virus, sometimes these outbreaks can last for a few weeks."

They said viral gastro was usually brought into care centres by visitors.

"Gastro is transmitted via person-to-person [contact] or by coming in contact with contaminated surfaces," the department spokesperson said.

With more people coming and going through the home during of the holiday season, a City of Greater Bendigo spokesperson said it was not unusual for a virus like gastro to last as long as it had.

"We have been very pleased with the facility's swift response and all the measures it has put in place to control the spread of the virus," they said.

Guidelines for the Investigation of Gastroenteritis recommend facilities managing a gastro outbreak limit visitors and restrict visitation to one resident only.

Honeysuckle Regional Health, which manages the home, has been contacted for comment.