Hong Kong recorded 33 new Covid-19 cases on Tuesday, the lowest daily total in nearly a month, as four more elderly patients died. The news came as a top infectious disease expert said he believed a cluster of infections in Kwong Wah Hospital in Yau Ma Tei, involving six patients, began when one of them failed to wear a mask properly. Among the new cases, of which there were fewer than 100 for the ninth day in a row, all but one were locally transmitted, including 15 without a known source. The imported case involved a seafarer from India. “I think there’s [a bit of] an overall decreasing trend, but the daily numbers may fluctuate,” Dr Chuang Shuk-kwan, head of the communicable disease branch of the Centre for Health Protection, said at the daily Covid-19 press conference. “I hope the trend will continue, with all the effort from the community as well as from the government, but there are still a lot of unknown cases in the city.” Among the new cases was a 40-year-old foreign domestic worker. The Indonesian national helped take care of an elderly woman in Shau Kei Wan from July 16 to 23, and stayed in a dormitory in Cheung Hing Mansion in Mong Kok with about 10 other helpers between July 23 and August 3. When we remove our mask and speak loudly, many tiny droplets are produced. If a patient is a carrier of the virus, those droplets pass the virus to other patients Infectious disease expert Professor Yuen Kwok-yung She recently began working for a new employer and tended to two elderly people living at the Chung Yuen Building in Tai Kok Tsui. After feeling unwell, she was tested and stayed at the Chung Kin Building while awaiting her results. Meanwhile, a 33-year-old man linked to Kwai Chung Container Terminal, where 10 cases had earlier been reported, was confirmed as infected. Three other people linked to the facility also tested preliminary positive. A 60-year-old man who sold chilled meat at the Yeung Uk Road Market in Tsuen Wan was also confirmed as infected. The Food and Environmental Hygiene Department closed the market early for deep cleaning and disinfection. Separately, a male nurse at Kwong Wah Hospital tested preliminary positive, though was believed unconnected to a Covid-19 cluster recently identified at the hospital. He most recently worked on Monday. His wife also works at the hospital and is being treated as a close contact. Professor Yuen Kwok-yung, an infectious disease expert from the University of Hong Kong, said he believed the cluster, which involved six people and three wards, possibly began when one of the patients did not wear a mask all the time. “The first patient was not cooperative. He often removed his mask and spoke loudly or shouted at people,” Yuen said after a visit to the hospital on Tuesday afternoon. “When we remove our mask and speak loudly, many tiny droplets are produced. If a patient is a carrier of the virus, those droplets pass the virus to other patients.” He said the transmission initially began with a 69-year-old male who infected another patient, who then spread the virus to three more people. One of those three then infected another patient. The spread among the other patients, Yuen said, could also possibly be attributed to instances when multiple people removed their masks at similar times, such as when taking meals or medication. In the case of the infected nurse, Yuen said he likely contracted the virus from a family member, who developed symptoms at similar time. Meanwhile, four more Covid-19 patients – aged 75 to 87 – have died, bringing the number of fatalities to 59. A 79-year-old man, who was being treated in Tseung Kwan O Hospital, died there on Monday at 11.19pm. The other three were an 87-year-old woman, who died at United Christian Hospital in Kwun Tong on Tuesday at 12.28pm, an 80-year-old man who died at Pamela Youde Nethersole Eastern Hospital in Chai Wan at 1.20pm the same day, and a 75-year-old man who died in Kwong Wah Hospital at 12.46pm. Medical experts have said that the elderly, who have weaker immune systems, are more prone to serious complications or even death after becoming infected by the coronavirus. Meanwhile, viral genetic sequencing from patients initially believed to have contracted Covid-19 during stays at Pamela Youde Nethersole Eastern Hospital showed the infections were from “different sources”, said Dr Sara Ho Yuen-ha, a chief manager at the Hospital Authority, suggesting transmission among them was unlikely. She added that results from other public hospitals with Covid-19 outbreaks, including Kwong Wah Hospital and Caritas Medical Centre in Cheung Sha Wan were still pending. Separately, the Hospital Authority announced that 400 more isolation beds in Exhibition Hall 2 of the AsiaWorld-Expo, located near the airport, would be ready for use as soon as later this week. Five hundred beds are already available in the first exhibition hall, while the city’s leader last week unveiled plans to place another 1,000 in the centre’s remaining halls, and up to 1,000 in a makeshift hospital near the site that will be ready in months. The new Covid-19 beds will increase the city’s total capacity by 2,400, to 4,950. The authority on Tuesday said the makeshift hospital will be two storeys high, and include such basic facilities as pharmacies and X-ray machines.