"I nearly died. I felt dizzy, was disorientated and when I got to the hospital they told me my life was in danger and I had lost a lot of blood. I only felt better after I was given a blood transfusion," said Modibedi, now 31.

Modibedi was lucky. In Botswana, which until recently had the world's highest rate of HIV/AIDS, contaminated blood can easily turn a life-saving transfusion into a death sentence.

The World Health Organization (WHO) says up to 10 percent of HIV/AIDS infections worldwide are caused by contaminated blood transfusions or blood products.

A new project called "Pledge 25" recruits young people to supply Botswana's hospitals with safe blood and educates them on how to stay free of the HIV virus that causes AIDS.

"The project targets in-school and out-of-school youth," said Dr Mukendi Kaembe, a National Blood Transfusion Service pathologist at the Princess Marina Hospital in the capital Gaborone.

"This is because most of them are not yet sexually active, which means they are still free from HIV. The project aims at making donors pledge to donate blood 25 times in their lifetime -- hence young people," Kaembe said.

The U.S.-based Safe Blood for Africa Foundation has helped Botswana's health ministry with Pledge 25 and other programmes to improve the quality and supply of blood.

Pledge 25 is based on a model which originated in neighbouring Zimbabwe and has been copied as far away as Malawi and Uganda, Haiti and India, according to WHO.

In Botswana, the programme is being piloted in a handful of places but given its success, it is now due to go nationwide.

LIVING HIV-FREE

The Foundation says projects like this have helped double Botswana's supply of safe blood in the past two years as well as halving the amount of HIV-infected blood donated through better screening of donors and counselling.

"We've added an element to the programme which basically counsels the kids to have an HIV-free lifestyle ... It's not just about donations," said Jeff Busch, a U.S. investment banker who founded Safe Blood for Africa after witnessing the problems that clinics around Africa face finding safe blood.

Botswana's life-prolonging HIV/AIDS treatment programme, funded by diamond dollars and U.S. aid, is already a model for other African countries at the epicentre of the AIDS pandemic, and now its safe blood donor scheme could also lead the way.

Building on its Botswana experience, Safe Blood for Africa has already started a similar pilot called "Club 25" in Nigeria, which is re-launching its blood transfusion service from scratch after years of neglect under military rule left people dependent on unregulated suppliers, increasing the risk of infection.

It is impossible to be 100 percent sure that donated blood is HIV-free due to a "window period" of several weeks after a person contracts the virus, during which it does not show on tests but is nevertheless infectious.

That makes donor counselling and screening vital, to make sure people who may have contracted HIV through unsafe sex during the preceding weeks do not give blood.

"You can not have 100 percent HIV-free blood (but) if you do it properly with repeat donors and questioning of donors, you can be above 99.9 percent HIV-free," Busch said.

Safe Blood for Africa has hired and trained blood collection experts, donor recruitment specialists and scientists to screen donors and test blood to ensure donations are free of HIV, hepatitis, syphilis and other sexually transmitted diseases.

SAVING LIVES

The group is also educating donors on how to avoid HIV.

"The most assuring thing that showed us that the project was working tremendously is the fact that the percentage of discarded blood has come down dramatically. This convinced me that people are keeping themselves clean and free of HIV," the National Blood Transfusion Service's Kaembe said.

Thato Leetile, 18, donates blood three times a year and says Pledge 25 has helped her stay healthy.

"I've been donating since 2003. This has helped me maintain my HIV status because we have been taught safe sex practices," says Leetile, a lively university student in the second year of a business administration course in Gaborone.

As well as improving their own chance of surviving an epidemic that has infected nearly two in five adults here, young donors are encouraged by knowing they are helping saving lives -- like that of Modibedi.

Sitting in her house in a middle-class neighbourhood of Botswana's capital Gaborone, her baby daughter Maduo asleep in a cot nearby, Modibedi praises the Pledge 25 volunteers.

"I believe it's very good that other people can donate blood because I nearly died."

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