A doctor and nurse at Tuen Mun Hospital may have caught Sars because their protective gear fitted poorly, court hears A doctor and nurse who caught Sars while working at Tuen Mun Hospital could have inhaled the virus when they wore their masks improperly, a medical expert told the Coroner's Court yesterday. Wong Tze-wai, a community medicine professor at Chinese University, said the N95 masks used at the hospital would not be effective protection against Sars unless a test was done to ensure they fitted snugly. 'Since both deceased were gowned and had gloves, the possibility that the infectious material reached [them] by touch is more remote, compared with the likelihood of breathing in the infectious material,' he said. Colleagues of nurse Lau Wing-kai had previously testified that they saw his mask and goggles slip out of place while he worked at the Sars ward of Tuen Mun Hospital last year. Joanna Tse Yuen-man, a doctor, was wearing a medium-size N95 mask while she resuscitated a Sars patient on March 28 last year. Since both she and Lau came down with fever around the same time, Professor Wong said yesterday it was likely they had contracted the disease while manually pumping air for the same patient that day. The coroner had invited Professor Wong to study how six medical workers had contracted Sars at their workplaces, before dying from the disease last year. The inquest began its third week of hearings yesterday. It is expected to end on Monday, when the jury will give its verdict as to whether the six died of natural disease, misadventure or other causes. Professor Wong referred to four other medical workers who contracted Sars and said he could not point to a specific incident in which they were infected. He said health-care assistants Tang Heung-may and Lau Kam-yung had close contact with patients who later turned out to have Sars at United Christian Hospital. Wong Kang-tai, an assistant at Prince of Wales Hospital, probably caught the disease while caring for the index patient - who eventually infected about 50 medical workers in the Sha Tin hospital, he said. As for Kate Cheng Ha-yan, a doctor at Tai Po Hospital, Professor Wong said she was well acquainted with the risks of infection. Still, she probably caught Sars through direct contact with patients or from hospital air contaminated by coughing and sneezing patients. He recommended that the Hospital Authority abandon the policy of reusing N95 masks and disposable gowns. He also recommended a review of the hospitals' ventilation systems and that staff be properly trained in the use of personal protective equipment. Sars is transmitted a short distance by respiratory droplets or through direct contact with patients, according to the World Health Organisation and the health department. Professor Wong said he belonged to a minority that believed the virus could be transmitted through air conditioning.