Health workers in Gejiu offer tests for H.I.V. and dispense methadone to drug users, as well as counseling and support for anyone with H.I.V. or AIDS. One group in the city has opened a drop-in center for parents of drug users to exchange information about how to prevent H.I.V. The city’s more than 1,000 prostitutes now can receive free condoms, tests for H.I.V. or advice on how to avoid becoming infected. Gejiu is emerging as a model of how China is trying to reverse its once abysmal record on AIDS. Recently, Chineseleaders have made AIDS a national priority and introduced a host of policies, while not too long ago China denied it had an AIDS problem and tried to cover up a tainted blood-selling program that infected untold thousands of farmers. Meanwhile, the police in some cities still arrest and harass advocates for AIDS patients or try to conceal the presence of the disease.