One in 10 patients who recover from Sars might suffer long-term lung damage, Hong Kong health chiefs revealed yesterday. But they refused to say if the damage was caused by the anti-viral treatment or the disease itself. Officials announced that all public hospitals had adopted a new treatment protocol in which the use of steroids on Sars patients had been delayed and cut. Secretary for Health, Welfare and Food Yeoh Eng-kiong said: 'We are now seeing a small group of about 10 per cent [of the patients] showing X-ray changes and they do not clear completely. We do not have sufficient experience to know what will be the outcome. But there may be some long-term consequences on their respiratory systems.' Up to yesterday, a total of 1,035 people had recovered from Sars. Seven people were added to the patients' list, taking the toll to 1,674. No medical workers were infected yesterday. A man, 79, and a woman, 73, both chronic patients, died yesterday, which was the lowest daily death toll in more than a month. Dr Yeoh said the Hospital Authority would launch a rehabilitation programme at Wong Tai Sin Hospital for patients suffering from lung damage after recovery. But he did not say how long patients would take to recover or whether they might suffer lung problems for life. Yu Wai-cho, a consultant with the department of medicine and geriatrics at Princess Margaret Hospital, refused to say whether the lung damage was caused by the treatment. The 10 per cent of patients were from different age groups, but most belonged to the group of more severe cases. Dr Yu said the remaining 90 per cent of patients had fully regained their health. He said only 80 per cent of patients responded to the antiviral treatment - a combination of steroids and ribavirin - instead of the 90 per cent at the beginning of the outbreak. A possible mutation of the virus or different channels of transmission, such as sewage pipes, could make the disease more virulent, which was why patients did not respond to the antiviral treatment as effectively as at beginning of the outbreak. Under the new treatment protocol, all public hospitals have started using steroids in the second week of the treatment instead of the first week. The aim is to minimise the use of steroids which could have serious side-effects, including increasing blood pressure. More new drugs, including Kaletra, pentaglobin, convalescent plasma and different immunosuppressants such as Azathioprine, have been added to the treatment protocol. Dr Yeoh rejected claims that patients had been overdosed with the drugs or the treatment had been wrong in the past. But he said doctors had changed their protocol after gaining clinical experience over the past two months. patsy.