SYDNEY, Dec 17 (Reuters) - Australian authorities on Friday rushed to track down hundreds who attended a Taylor Swift album party in Sydney last week that has become a super-spreading event as cases in the country hit a new pandemic high for the second straight day. COVID-19 infections, including the new, more transmissible Omicron variant, have been spreading in pubs and nightclubs as social distancing curbs ease after higher vaccination levels. Despite the surge in cases, Prime Minister Scott Morrison said Australia had entered "a different phase of the pandemic" and ruled out lockdowns to contain the spread of the virus. "Case numbers are no longer the metric ... the real measure is what does it mean for serious illness, (intensive care), hospitalisation, pressures on the hospital system," Morrison said during a media briefing on Friday. He said initial signs suggest the Omicron variant could be less severe than other variants. At least 97 cases, including some potential Omicron ones, have been detected among people who attended the Taylor Swift theme party. More than 600 people who checked in at the venue must test and self-isolate but officials flagged there could have been more guests. A record 3,820 cases were reported in Australia on Friday, with the bulk in its most populous states of New South Wales (NSW) and Victoria, exceeding the previous high of around 3,400 a day earlier. NSW authorities have warned daily cases could hit 25,000 in the state by the end of January with authorities looking to accelerate the rollout of booster vaccine shots to ward off the threat from the Omicron strain. Health officials blamed gatherings at pubs and clubs for the "rapid rise" in cases. "Some of these have led to super-spreading events," NSW health official Jeremy McAnulty said. Neighbouring Victoria, meanwhile, is on alert after an Omicron-infected person attended a busy pub and hotel in Melbourne. Australia has reported around 243,000 cases and 2,134 deaths since the pandemic began.