CALLERS to a new AIDS hotline are nearly nine times more interested in finding out how to use a condom than in learning about the risk of catching AIDS through sharing needles, Health Department statistics have revealed. Since the new bilingual computerised system was launched on April 27, interest has increased twenty-fold, with more than 25,000 people dialling 780 2211 for AIDS information. That compares with the average of 1,300 a month who called the previous number. The message about how to use and remove a condom was the most popular, with 6,459 callers, while 717 callers opted for information about AIDS risk from intravenous drug use. Others chose to hear about the HIV antibody test, a general recording about AIDS and a recording about women and AIDS. About 4,000 people wanted to get through to one of the nursing counsellors. ''This is encouraging,'' said Department of Health consultant Dr Lee Shui-shan. The message tells callers to use condoms whenever they have any doubt about whether their sexual partners might have venereal disease. The recorded message on the risk of catching AIDS through intravenous drug use was designed more for general information, with people in high-risk groups encouraged to get more individual help, Dr Lee said. ''Many people used to find they could not get through before, while in the past month 87.5 per cent of calls have been answered,'' he said. Latest government AIDS statistics show that four people were found HIV-positive during April, bringing the total number of recorded cases in Hongkong to 359. All four were male: two were heterosexual, two did not declare their sexual preference. Three of them were Chinese. ''This continues a general trend where new HIV cases are more likely to be heterosexual than homosexual, and where more Chinese people are catching the virus,'' Dr Lee said.