Uganda's First Lady has called for a census of the sexual habits of the country's younger generation as part of the fight against HIV/Aids.
A Ugandan poster encouraging abstinence
"We need to find out the percentage of the youth who never had sex, those who have reverted to secondary abstinence," said Janet Museveni.
Uganda is often held up as a model of how to fight Aids.
In the early 1990s, some 15% of adults were HIV positive but after a vigorous campaign, this has fallen to 5%.
Mrs Museveni has backed a campaign for young Ugandans to pledge abstinence until marriage and next week will host a party for some 70,000 virgins.
They are due to march through the streets of the capital, Kampala, on their way to the event, reports the New Vision newspaper.
Abstinence has always been part of the Ugandan government's campaign against HIV/Aids but condoms have also been well promoted.
In September, South Africa's Deputy President Jacob Zuma called for girls to take virginity tests to help reduce the spread of Aids.
This was countered by human rights groups, who said that virginity tests were a human rights violation.
Speaking on World Aids Day, Mrs Museveni said she feared that Uganda's early success against Aids was not being kept up.
"The fact that prevalence rates of HIV/Aids have not continued to drop as in the late 1990s, in my opinion, it means this country did not keep up the momentum of the campaign that yielded significant results," she was quoted as saying by the Monitor newspaper.