The survey had been intended to determine the prevalence of AIDS infection.
But the real incidence of AIDS infection among this group probably is 10 per 100,000.
Researchers call it the most valuable research project on AIDS infection and disease.
The young women had a slightly lower rate of AIDS infection - 5.4 percent.
The results showed that those who did not cooperate the first time were indeed at higher risk for AIDS infection.
None of them tested positive for the AIDS infection, a city health department official said later.
The need to control AIDS infection among addicts has been rising.
However, the body does not produce the antibodies during the first few weeks of an AIDS infection.
In both countries, the incidence of AIDS infection is now rising.
Drug use is not a significant source of AIDS infection in Africa.