HONG KONG, Feb. 11 (Xinhua) -- Four Hong Kong sisters, aged between two to 17 years old, have tested positive for type-A influenza, said a spokesman of Princess Margaret Hospital Wednesday.

    All of the four girls are in stable conditions now, he said.

    The four girls, having symptoms of fever, runny noses, and coughing were admitted to Princess Margaret Hospital Wednesday and they were put into in the isolation wards immediately. They received rapid influenza-A tests and SARS tests afterwards.

    The results of SARS (Severe Acute Respiratory Syndrome) tests will come out later, said the spokesman of the hospital.

    A Hospital Authority spokeswoman said samples had been sent tothe Department of Health for further tests on whether the four girls had the deadly H5N1 bird flu that is sweeping Asia.

    The four girls did not have any contacts with poultry, the maintransmission ways of the wide-spread bird flu in a number of Asiancountries and regions.

    In a related development, 10 patients with fever in Prince of Whales Hospital tested negative for SARS and H5N1 bird flu Tuesdayand Wednesday.

    Medical experts said Type-A influenza has 15 varieties ranging from H1 to H15. The widespread bird flu in some Asian countries and regions is described as H5N1. Enditem