Source of 1,600 Victorian healthcare workers' Covid-19 infections still unknown despite premier's claims

The Victorian government does not know where almost 1,600 Covid-19 infections among healthcare workers – almost 85% of such cases – were acquired, according to an email seen by Guardian Australia.

A message sent to health workers by the peak Victorian authority for safety improvement in healthcare says it is still examining the source of the majority of infections, calling into question claims from the state’s premier, Daniel Andrews, and health minister, Jenny Mikakos, that most workers were infected in the community.

The email sent by the chief medical officer of Safer Care Victoria, Prof Andrew Wilson, says as of 8 August, 1,835 healthcare workers had been infected with the virus.

The figure includes healthcare workers with active infections and those who have recovered from the virus. Of those infected, 50 were confirmed to have acquired the virus in a healthcare setting, Wilson said, including 12 doctors, 29 nurses and nine other health practitioners such as paramedics and allied health workers.

Related: Victorian doctors disturbed at patchy supply of PPE for Covid health workers

Wilson, who also chairs the Victoria PPE (personal protective equipment) taskforce, said in an email: “Healthcare acquisition remains under investigation for 1,598 healthcare workers.”

It calls into question statements from the health minister, Jenny Mikakos, before the parliamentary inquiry into the Victorian government’s response to Covid-19 that up to 15% of those with active infections had been infected at work. The source of many cases are still under investigation. She said Wilson would be investigating how health workers were becoming infected.

“We’ll be engaging with organisations to drill down to the heart of these issues and what more we could do to protect our dedicated healthcare workers in their important work,” Mikakos said on Tuesday.

Asked by Guardian Australia to clarify Mikakos’s comments, a spokesman for the Victorian Department of Health and Human Services said while “early” analysis of public health data was showing that the majority of healthcare workers are acquiring coronavirus outside of work, “further detailed analysis is under way to better understand the nature of transmission for the smaller proportion of cases that are acquired in the workplace”.

“It is important to understand if this is occurring between colleagues, on a break for example or from patient to doctor, even with PPE,” he said. “Healthcare workers also cover a range of settings so it is also important to break this down into aged care, primary care and hospital settings so we have a clear picture of what is happening. This further analysis is under way and we should be able to share the results early next week.”

Related: Victoria's coronavirus death toll climbs to 246 as senior officials grilled at inquiry

The premier, Daniel Andrews, told reporters on Wednesday “the majority of healthcare workers are acquiring coronavirus outside of the workplace”. “I’m not making any judgments about that, that is what the data is telling us,” Andrews said. But he did not say most infections were still under investigation.

A doctor working at a major public hospital in Melbourne told Guardian Australia she was angered that politicians were not being publicly transparent. “The work itself is not a problem when we feel the appropriate safety practices are in place,” she said. “It’s seeing the massive numbers of healthcare worker infections – the denial of the significance of those infections, that is the greatest source of anxiety.

“No one would begrudge the government openly stating they don’t know [the source of infections] but they’re working hard to figure it out. The hospital I work at was hit hard – 136 staff infected, at least 460 more furloughed since early July. But they showed real leadership and openly admitted many cases were acquired at work, upgraded their safety policy, and there was transparency of reporting and a commitment to focus on safety. As a result morale is surprisingly high. I would like this to be across the board, with many hospitals still are not transparent about the number of workplace infections.”

She said he suspected the 50 confirmed workplace infections would prove to be much higher. “There would be more than 50 at my hospital alone,” she said.

The email from Wilson said the PPE taskforce had endorsed the needs-based allocation of N95/P2 respirators, and allocations for each health service would be based on the size of the workforce, with weighting towards use in intensive care, emergency departments and Covid-19 wards, especially “when undertaking emergency surgery and aerosol-generating procedures”.

“The allocation model is designed to over-allocate rather than under-allocate,” the email said. “As such, the usage assumptions driving the model are slightly above the current advice on the appropriate use of PPE. Health services should adhere to current PPE advice, rather than the usage assumptions in the model.”