THE piercing siren of the ambulance sent a chill through the mother as she watched it heading towards the hospital where she had just left her son. Just then, she had a premonition and instead of returning home, ran up the steep hill to the hospital's accident and emergency department. Her worst fears were confirmed. The ambulance was rushing her second son in for treatment. In one day, both her haemophiliac children had suffered falls that could prove fatal. A decade on, as she reflected on that ill-fated afternoon, the mother of seven lives in fear of the day when the brothers - one of them blind and crippled - develop full-blown AIDS. She had already lost one child to haemophilia 30 years ago, when treatment was not available. The advent of Factor VIII concentrate, prepared from blood plasma, had given her hope for her two other sons suffering from the disease. But what then seemed a blessing could prove to be the killer blow. It was about the time they were admitted for their falls, if not the same afternoon, that they were unwittingly administered Factor VIII, contaminated with HIV, the deadly virus that causes AIDS. ''I have already prepared myself for the day when they develop AIDS,'' said the mother, who wishes to be called Mrs To. ''I have even thought up some lies. When my neighbours see my sons losing weight they are bound to ask questions and I will tell them they have had cancer - both of them. ''This is my life, the tragic life of a mother who gave birth to three haemophiliac children.'' A total of 61 Hongkong haemophiliacs have contracted the AIDS virus through tainted blood products administered to them in Government hospitals. But while thousands who shared their plight across the world have received compensation, victims in Hongkong are left to suffer silently, and live in the shadow of the stigmatised disease. The Hongkong Government recently agreed to reply to the haemophiliacs and their families' plea for compassion by early March, following the launch of the Sunday Morning Post campaign, but until then Mrs To is left to fend for herself. Looking back, she has to admit the worst that has happened to her was not the death of her first son. That was terrible but it was over quickly. ''The worst thing was to see my sons suffer, especially Ah-wing, who is blind and crippled,'' she said. Ah-wing was diagnosed as a haemophiliac when he was one-year-old. ''He was a healthy boy apart from the genetic blood disease,'' she said. ''He could see and he could walk.'' Bad luck struck when the boy turned three. It was just before Chinese New Year 20 years ago, when he fell from his bed. ''It was not a nasty fall,'' Mrs To said. ''He did not vomit or bleed. The doctor thought he was fine. ''Then his health started to deteriorate. I took him to another doctor. About 10 days later . . . and an in-depth examination revealed he needed to be admitted to hospital, with suspected bleeding in the brain. ''When we checked him in he was still conscious. He was asking me for a bottle of milk. ''But two days later he fell into a coma. The doctor said he needed brain surgery right away. When he came out of the operating theatre the surgeons had drilled two holes in his brain.'' For 40 days or more Ah-wing remained unconscious. When he finally woke up, Mrs To thought he had pulled through. ''He looked fine to me, he was eating all right,'' she said. ''Then one day it suddenly occurred to me he might not be well after all - when I fed him he would not open his mouth until he felt the spoon on his lips. ''It was as if he could not see. When the nurse finally told me he could go home I was shocked. I told the nurse of my suspicion - that my son could not see. ''A nurse later confirmed my son needed to consult an eye specialist. She also recommended a physiotherapist because Ah-wing could not use one of his hands and his legs. ''Twice a week, for several years, he had to have physiotherapy until he was old enough for the school for the blind.'' Mrs To said it was after the surgery that Ah-wing's health took a serious turn for the worse. ''The surgery was not a success,'' she said. ''Since then Ah-wing has spent very little time with us. Most of his childhood was spent either in hospital or in the school where he boarded until he was 17.'' Then, learning to use the stairs in school, he had another fall that cost him his school place. ''He was not very good at school,'' Mrs To said. ''His sense of touch was not as good as many of his schoolmates. I think that was because he was not born blind. ''But school gave him company. He always enjoyed it until he was forced to leave.'' Recalling the events of a decade earlier, Mrs To said she was taking her youngest son to hospital, also after a fall at school. ''I left him in hospital,'' she said. ''I was waiting for the bus when I saw this ambulance. I had a very nasty feeling. I ran all the way to casualty and there was Ah-wing. ''He went into a coma and needed brain surgery. I waited for him for hours - it was eight hours or more before he was wheeled into intensive care. ''I was on my own. I knew no hunger - only fear. Ah-wing was in a very bad state. I remember he had this huge machine by his bedside. His thigh had swollen. He was bleeding. I THOUGHT he had suffered enough and I told his doctor to let him die. I could not bear the sight of him suffering anymore. ''But the doctor said he would do his best to save him. He said Ah-wing wanted to live. On the fifth day he woke up from his coma, but had to be hospitalised for three months. ''My whole life revolved around him. There were only two visiting periods at the hospital, with a one-hour gap in between. I wanted to be there when my son woke up, so every day for three months I had to kill this one hour by walking around Sheung Wan. It was either that or sitting in hospital watching and hearing people in pain. ''At the end of that three months I started to take tram trips to kill time. It was a waste of money but I felt too tired to walk. ''I needed to spend more time with him. Unlike other children he could not bathe or feed himself. When he was finally discharged he was like a skeleton. ''There was nothing left of him but skin and bones. It was a tragic sight. ''Why didn't he die? Why did he have to suffer so much? ''When he finally recovered the school said they did not want him back. They said they didn't have enough people to look after him. ''Since then he has spent all his time at home. ''He has had brain surgery three times. There were three or four times he nearly died. There were 10 to 20 times when he had to be rushed to hospital.'' But the worst was to come, three years ago, Mrs To learned both Ah-wing and his younger brother, 18-year-old Ah-keung, had contracted the AIDS virus. ''It was a nurse who broke the news to me,'' she said. ''There was no counselling. I was only told to go home and buy him disposable plates and cups. I was also told to throw away everything he had touched - his clothes, his bed sheets. ''I was not upset about his disease, but what the misinformed nurse had told me. I was really scared. ''I remember I went home feeling very upset. I took what I had been told seriously until I could stand it no more - how could I afford to throw away clothes and blankets and bed sheets like that? ''I was already spending a lot on needles, on bandages and cotton balls because I have two sons who are haemophiliacs. ''I sought advice from a private doctor who has helped to calm my nerves. But I have had no counselling from the authorities. Until now, there has been no counselling. Nobody tells me how or what to do. ''My second son is also a carrier but because he is not handicapped, he can manage relatively well. When he is in hospital he can buy his own food. With Ah-wing it is different, he cannot see and he cannot walk.'' Mrs To said she had never thought of complaining to the authorities about the treatment in hospitals. ''It is no use complaining because I have got two sons who are ill all the time,'' she said. ''Today you complain about one doctor, tomorrow you have to go back to him for help. It is always better to keep quiet. ''There was one time - after we had just been told Ah-wing was HIV infected - I visited him in hospital. Every other person in the ward was having their meals but him. There was no water either. When I asked for some I was scolded by a nurse. ''It is never easy. Since then I have always made sure he gets his share of food in hospital.'' But both her sons have tried their best to avoid hospital. ''They never like the hospital and will not go in unless it is absolutely necessary, especially when privacy simply does not exist for HIV-carriers,'' she said. ''Ah-keung thinks it is humiliating to be given disposable bowls and have the word HIV written at his bedside.'' He is still in school but nobody knows he is a carrier - not even his closest friends. But the teenager has found living a lie a dilemma. ''When he is in hospital, he asks me to lie for him, to tell classmates who ring up that he is staying with a relative,'' Mrs To said. ''He does not want his classmates to visit him in hospital and find out about his disease just by standing at his bedside.'' The 51-year-old mother was in tears when she recalled another episode at the hospital. ''I am illiterate,'' she said. ''When I had difficulty signing my sons in, I was scolded by the nurse. She was screaming at me for not knowing how to write my name. ''I suffer so much humiliation in hospital. I am crying now not because I want you to pity me, but because when I start recalling how I suffer in hospitals I am so angry that I can no longer hold back my tears.'' But Mrs To said the cruellest thing that had happened to her was having two sons with the HIV virus. ''I have always accepted fate but I am beginning to worry for Ah-wing,'' she said. ''He cannot take care of himself. He cannot even pour his own water. All day he either sits in his bed or in the wheelchair. ''The only thing he can manage on his own is to eat and listen to music. He can barely use the cassette, even pressing the buttons is a task. It is extremely frustrating for him. ''Ah-wing sometimes asks me what I would do if I were rich. I tell him I would like to travel. ''I have never been anywhere all my life, except my hometown in China.'' But leaving Ah-wing presents too many problems. ''I would have to get help from one of my daughters, who would have to take time off work to tend to Ah-wing while I was away,'' she said. ''He cannot be left alone at home.'' Mrs To said her other worry was Ah-keung, who unlike Ah-wing, was fully aware of the implications of the disease. ''He has never indicated to me how he feels,'' she said. ''He ignores me when I bring the subject up. But I am worried. He is 18 and girls always ring up for him.'' Mrs To said there should be counselling, not only for patients who had developed full-blown AIDS but also for HIV-carriers and their families. On the issue of compensation, she said: ''I have seven children and I have always managed. I have accepted fate. But I am old now. It is not like the old days when I could rush him to hospital, running up and down the stairs with him on my back. ''I cannot carry him any more. Since he has stopped his physiotherapy he has lost his ability to walk. He has to be helped to the toilet. ''I need help because now I am too old even to wheel him to the park for some fresh air. ''If I had money I would hire somebody, such as a Filipina maid, to look after Ah-wing so I can have some breathing space.'' What if compensation were not forthcoming? ''If I die, Ah-wing will have to come with me,'' she said. ''It will be so sad for him if I leave this world on my own, especially now he is an HIV-carrier. There will be no institution which will take care of him. ''In Hongkong even those who are severely handicapped have problems being accepted by the community. His father loves him but he is over 60, he won't be much help. ''I dread the time when he develops full-blown AIDS - when both of my sons become AIDS patients. I am beginning to feel the pressure.''