Professor Mary-Louise McLaws, who helped guide Australians through the COVID-19 epidemic, had died at the age of 70.

The world-renowned epidemiologist, who became a fixture in Australian media with her calm and reassuring health advice in a time of great uncertainty, had been suffering from a brain tumour.

The University of New South Wales Professor reportedly died peacefully in her sleep on Saturday night – about 18 months after being diagnosed with a brain tumour.

Professor McLaws was appointed an Officer of the Order of Australia (AO) in the 2022 Queen’s Birthday honours list for ‘‘distinguished service to medical research, particularly to epidemiology and infection prevention, to tertiary education, and to health administration’’.

Professor McLaws became an adviser for the World Health Organisation in 2002 when helping control the spread of SARS in Hong Kong and in Malaysia, before becoming a member of WHO’s Infection Prevention and Control Global Unit.

She was appointed to the WHO experts advisory panel for infection control for COVID-19 in 2020.

Deputy chief medical officer Professor George Rubin led a long list of tributes, saying Professor McLaws was ‘‘the most trusted voice in Australia’’.

Former Australian Medical Association vice-president Stephen Parnis echoed the sentiment, tweeting “We grieve a great loss, but honour such a singular & powerful contribution to Australian Public Health’’.

Tweet from @SParnis

Professor Adrian Esterman, a fellow epidemiologist from the University of South Australia, lamented the loss of ‘‘an esteemed colleague and a voice of reason’’.

Dr Monique Ryan, who is now the federal Member for Kooyong but was previous head of paediatric neurology at Royal Melbourne Hospital, tweeted ‘‘Such a sad loss for this country’’.

Professor McLaws is survived by her husband Richard and her children Zia and Zachary.