The novel coronavirus can live for up to 28 days on banknotes, glass, and stainless steel in a very controlled climate, even longer than the flu virus, Australian researchers said on Monday, emphasizing the need for cleaning and handwashing to fight the virus.

The findings of the research undertaken by CSIRO, Australia's national science agency, were published in the Virology Journal.

CSIRO researchers observed that on smooth surfaces such as plastic banknotes and glass observed on cell phone displays, the SARS-COV-2 virus remained contagious for 28 days at 68 degrees Fahrenheit. By contrast, it was observed that the Influenza A virus lived on surfaces for 17 days.

"It really reinforces the importance of washing hands and sanitizing where possible and certainly wiping down surfaces that may be in contact with the virus," said the study's lead researcher Shane Riddell.

The study involved drying the virus in artificial mucus at concentrations close to COVID-19 patient samples on a number of surfaces and then recovering the virus for a month.

The virus lived longer at colder temperatures, longer on flat surfaces than on complex surfaces such as cotton, and longer on paper banknotes than on plastic banknotes, according to experiments performed at different temperatures. The study was also performed in the dark to reduce the effects of UV radiation, as testing has shown that direct sunlight will easily inactivate the virus.

According to the team, although it is still necessary to determine the specific function of surface transmission, the degree of surface contact, and the amount of virus required for infection, understanding how long this virus stays viable on surfaces is crucial for high-contact areas to develop risk reduction strategies.

Professor Trevor Drew, Director of the U.K's Advisory Committee on Dangerous Pathogens, said that many viruses remained viable outside their host surfaces. And their analysis can help understand the apparent longevity and dissemination of the virus in cool environments such as meat-packing plants, provided that proteins and fats in body fluids may also sharply improve virus survival periods.

In combating COVID-19, Australia has fared much better than most other wealthy nations, with a total of about 27,000 infections and 898 deaths in a population of 25 million.

On Monday, Victoria state, the epicenter of the country's second wave of infection, reported 15 new cases, well shy of a target of less than five that the government has set for the easing of a hard lockdown in Melbourne, the state capital. The most populous state, New South Wales, reported six new cases on Monday, five of which were returned to quarantine travelers.