A scientific study says there has been a significant drop in the number of Aids cases in Uganda.
UNAids has urged African leaders to speak publicly about the disease
The study in the journal, Science, attributes the decrease to a successful public education campaign.
This has led to a reduction in the number of people having casual sex, as well as the willingness of Ugandans to openly discuss HIV issues.
The scientists called for the Ugandan approach to Aids prevention to be adopted in other countries.
HIV cases in Uganda dropped by 70% in the 1990s.
The government's message clearly stated that Aids was deadly and that it spread through sexual activity.
Because of this, HIV is now openly discussed amongst friends and family.
This led to a fall of 60% of people reporting they had casual sex.
Other African countries studied have similar levels of condom use as Uganda, but little reduction in the number of sexual partners.
According to the scientists, only a vaccine - as yet undeveloped - that worked in 80% of all cases would have a similar effect.