The incident at the Australian Taxation Office in Parramatta coincides with union calls for federal employers to explain their plans to prevent the illness from spreading in their workforces.

An ATO employee taped off the desk of a colleague who was away, after it was wrongly believed he had been a patient of a doctor with the coronavirus.

The Tax Office, which did not authorise the employee taping off the desk, investigated and learnt the public servant did not have symptoms of the virus.

He had been told by his hospital he was not at risk and would not need testing.

A Tax Office spokesman said it was monitoring the COVID-19 outbreak and would take advice from health authorities.

The Australian Services Union representing tax officials has proposed measures to the ATO to prevent the virus spreading.

Defence bureaucrats have to notify their department ahead of any business or personal travel overseas as the major Commonwealth employer ramps up its preparations in the face of the COVID-19 outbreak.

A Defence Department spokesperson said its secretary Greg Moriarty and Defence Force chief Angus Campbell were updating staff about the impact of the virus on the department, as well as hygiene measures and social responsibilities aimed at minimising community transmission.

Other measures to prevent infections included health alerts, a specific COVID-19 intranet page and advisory posters.

Defence is working with ACT and NSW health authorities to isolate and trace contacts in cases where Australian Defence Force personnel have tested positive for the virus.

"Defence personnel assessed as close contacts in accordance with Department of Health guidelines are directed to self-isolate," a spokesperson said.

"ADF members who develop symptoms are required to seek a medical assessment from their Defence Health facility.

"Civilian staff are instructed to contact their GP or a state-provided testing facility. These individuals will then be tested and managed under the direction of the public health unit with Defence providing support to staff and authorities as required."

Defence's public service employees and ADF members are able to work from home if they show symptoms or contract COVID-19.

"If this is not practical or there is no facility for working remotely, other paid leave options are available for the quarantine period."

The main public sector union said it was discussing risks of COVID-19 exposure with government agencies.

Community and Public Sector Union national secretary Melissa Donnelly said the public service commission overseeing bureaucrats had advised they would have access to paid leave, including paid miscellaneous leave or work from home arrangements, if quarantined.

"But we are increasingly concerned that the government is refusing to provide clarity if casuals, contractors and labour hire workers will be covered by this arrangement," she said.

"The CPSU is calling on the government to ensure that no worker is worse off and are provided with paid leave. This is not just a matter of equity, it is about the essential public health response."

READ MORE:

Professionals Australia, representing Commonwealth scientists, pharmacists, translators, interpreters and engineers, said safety must be the primary concern.

The union's ACT branch director Dale Beasley said the unavoidable consequence of measures like home-based quarantine would be limitations to delivering business as usual.

"We need open and transparent dialogue between agencies, their employees, industry and the community about the impacts so that we can all make the necessary plans," he said.

"We know that agencies are developing contingency procedures like work-from-home arrangements, we also know that some agencies are restricting international and interstate travel, but detail is patchy.

"We need clarity on how these steps are going to impact service delivery and the functioning of workplaces.

"How is an aviation safety inspector, a biosecurity officer, a transport safety inspector, or a trade measurement officer meant to deliver their particular public service with restrictions like these in place?

"The impacted industries need answers to those questions, and so do the impacted employees."

Government departments flagged that they had "business continuity plans" prepared in case large numbers of staff are forced to self-isolate or, in extreme, the government orders a lockdown similar to that in place in Italy.

One of the most critical agencies is Services Australia, which is responsible for Centrelink, Medicare, child support payments and, most recently, bushfire recovery assistance.

Services Australia spokesman Hank Jongen said the organisation had "plans in place to ensure our staff are well supported, and to ensure we continue to deliver services to our customers in the case of an escalation in the incidence of COVID-19".

There are concerns that a virus outbreak could result in severe disruptions, putting many vulnerable people dependent on government support payments at risk.

But Mr Jongen tried to provide reassurance.

"Customers will be given clear direction if our business is disrupted in any way, ensuring they have options to continue accessing our services," he said, adding the agency was working closely with other departments and agencies to ensure a coordinated approach to the delivery of essential services.

The Health Department said it had a continuity management team monitoring the situation and assessing risks, and was following the advice of the Australian Health Protection Principal Committee.

"Like with the recent national bushfires, the team have (sic) plans in place if parts of our workforce become affected to ensure core business processes continue," a department spokesman said.

The department said its business continuity plan included arrangements to allow staff to work from home if necessary.

"Staff can work from home when in isolation. If work from home is not possible, miscellaneous leave with pay will be provided," a spokesman said.

Other departments including Prime Minister and Cabinet and Finance said they had plans in place to ensure the continuity of their operations in a range of situations, including a possible pandemic, but did not provide details.

All departments contacted said they were closely following the advice of the Chief Medical Officer Dr Brendan Murphy.

Comment was sought from the Department of Foreign Affairs and Trade and the Department of Home Affairs.

We have removed our paywall from our stories about the coronavirus. This is a rapidly changing situation and we to make sure our readers are as informed as possible. If you would like to support our journalists you can subscribe here.