Perth, Nov 17 : The Department of Health in Western Australia (WA) confirmed on Friday that the mask-wearing requirement would be strengthened across the state's public hospitals in response to rising Covid-19 cases. According to a statement by WA Health, from November 20, staff and patients must wear surgical masks in high-risk clinical areas, including hematology, oncology, organ transplant, and renal dialysis, and around vulnerable patients in critical care settings like intensive care units, reports Xinhua news agency. The latest figures showed that in the week of November 6 to 12, there were 531 Covid-19 cases reported in WA, 14 per cent higher than the previous week. The state's Chief Health Officer Andy Robertson observed that Covid-19 cases had been rising since early September, primarily driven by the Omicron XBB variant EG.5. "It's an expected part of the ongoing evolution of Covid-19 in the community as people's immunity wanes over time," he said. Apart from WA, other Australian states were also on high alert for Covid-19 infections. As Australia's most populated state, New South Wales recently saw a "moderate to high" spread of the disease, with the local health authority encouraging people to keep up to date with their vaccinations. The Victorian Department of Health issued a warning in late October, reporting that the community transmission of Covid-19 is increasing statewide. "After a period of slow increases from July, recent weeks have seen increases to levels not observed since May," the Department said. /IANS