Health officials have warned Covid-19 infections are rising in Hong Kong as new cases once again surpassed 500, with the increase stemming largely from snowballing outbreaks at bars in a popular entertainment district in Central. The city on Sunday confirmed 515 new infections, the most since April 23 when 523 cases were recorded. Of the latest cases, 41 were imported, while four more deaths were logged. The tally included 379 infections discovered by residents using a rapid antigen test (RAT), but health officials have previously warned of a recent increase in the number of outdated RAT results as some people had tried to report a past infection to satisfy the three-dose requirement of the vaccine pass. Dr Chuang Shuk-kwan, head of the communicable disease branch of the Centre for Health Protection, attributed the recent increase in infections to several factors, including relaxed social-distancing measures and a discrepancy between actual infections and reported ones, while also noting the upwards trend was in line with the findings of a study. “The infection numbers have tended to be high in the past few days,” Chuang said. “It is consistent with the findings of a University of Hong Kong [HKU] study, which shows chances of an upwards trend.” Chuang noted that 44 cases reported on June 2, or 14 per cent of the total, turned out to be wrong after double-checking, higher than the roughly 20 per cent on average for last week. She noted that HKU’s estimate of the “effective reproductive number” of the virus was 1.353 on May 28, slightly higher than one. But Chuang said authorities had not observed changes in the number of severe cases or an increase in rates of hospital admittance. Covid-19 clusters linked to clubs in popular Hong Kong nightlife area worsen No new bar clusters were reported on Sunday, but an outbreak linked to Shuffle nightclub in Lan Kwai Fong expanded by 27 cases, taking the total to 69, while 13 more infections were connected to Linq bar, bringing the number to 78. Two more cases were tied to Zentral, taking the total to 37, and another three cases were discovered in connection with the Iron Fairies nightspot, raising its total to 56. Officials took 21 environmental samples at Shuffle, 20 of which came back negative. One sample from a toilet doorknob remained unconfirmed. “People involved in the club clusters are mainly quite young. Most of them have mild symptoms including sore throat, fever and runny nose,” Chuang said. The residents who were infected at the bars were most likely to be carrying the predominant BA2.2 strain, although further genome sequencing was needed for confirmation, she said. Chuang urged patrons who had visited any of the affected bars around the time the first cases emerged to undergo mandatory tests or risk legal action. Meanwhile, three doctors working in the intensive care unit at North District Hospital in Sheung Shui tested positive. Their last day of work was Thursday and they had no contact with patients confirmed to have Covid-19 in the last 14 days. They also wore protective equipment when working. No patients were currently listed as close contacts, but the hospital has arranged disinfection and testing for all patients and staff members. Hong Kong’s Covid-19 tally stood at 1,215,153, with the death toll at 9,386.