Aged care staff are worried they will infect residents with COVID-19 amid rising case numbers as the sector manages hundreds of outbreaks nationwide.

As of January 5 there were 411 active outbreaks in aged care facilities across Australia, according to the federal Health Department.

Facilities that record a positive infection are given a case manager to assist with support, extra PPE and a "surge workforce", but the union says more needs to be done as the highly infectious Omicron variant spreads rapidly.

"It's a huge emotional burden (on staff), thinking that they might be the ones who bring the strain into the facility," United Workers Union aged care director Carolyn Smith says.

Evidence suggests the variant causes comparatively milder symptoms among healthy people, which can make it harder to detect, Ms Smith said.

And it can still be "incredibly dangerous" for nursing home residents, she says.

"They're in nursing homes because they're very unwell. They're very frail. Often they have multiple kinds of medical and physical issues."

The Health Department says resident care is "the number one priority", and its surge provisions include dedicated nursing staff and agency workers "as well as agreements with private hospitals to provide support if states seek to utilise this resource".

"It remains the case that each state, through their public health unit, provides advice on the furloughing of staff when a (residential aged care facility) is impacted by COVID," a department spokesperson said.

But having managed shortages that existed before the pandemic began, and were exacerbated when the borders shut, the sector is at a "crisis point" as high case numbers force more people into isolation, the union says.

"We are hearing stories of one person caring for 30 residents ... you cannot even do basic care with that sort of ratio," Ms Smith said.

"The government has talked about ... a surge workforce. Now is the time to start actually doing some real workforce planning and getting extra staff into aged care."

The next report into COVID-19 outbreaks in residential aged care facilities is due to be released on Friday.