Stella Nayiga clutches her mobile phone as she describes the messages that she received punctually every morning and evening for over a year, reminding her to take her antiretroviral (ARV) drugs regularly.

"The text messages would come twice a day and were saying things like 'Dear friend, please take care of yourself' and when you got them you knew it was time to take your medicine," Nayiga, 28, told AFP.

"As a human being you can always forget to take the drugs -- maybe not for the whole day but sometimes for some hours -- but this service really helps you to remember."

An HIV-positive health worker in the Kampala suburb of Kawempe, Nayiga was part of an innovative scheme that used mobile phones to help remind around 400 patients diagnosed with the virus to take their ARVs regularly.

A collaborative project between a local clinic and a Dutch-run non-governmental organisation, the programme is part of an attempt in Uganda to harness the power of mobile technology to help fight HIV.

Those involved say that it soon became clear that receiving the daily messages was a big help for the people taking the drugs.

"We saw that because of the mobile messaging there was a really tremendous improvement in adherence," said Samuel Guma, director of Kawempe Home Care, which runs the clinic involved.

ARVs -- taken twice daily -- require a minimum adherence rate of around 95 percent to be truly effective and the SMS scheme saw the number of people taking the drugs correctly rise from 75 percent to over 90 percent.

Sitting in an office in an upscale suburb of Kampala, Bas Hoefman, founder of the Dutch-run NGO Text to Change, the organisation behind the text messaging programme, lists the different ways mobile phones can be used to fight HIV.

Starting off in Uganda five years ago, Text to Change used SMS quizzes to try and educate people about HIV issues and encourage them to go for testing -- sometimes offering incentives such as phone credit.

Since then the organisation has run over 30 HIV-related projects using mobile phones across Africa, such as promoting medical male circumcision in neighbouring Tanzania -- and has reached an estimated 1 million people in Uganda alone.

"There was a fatigue for people receiving the old messages via traditional media -- mobile phones are now so commonly used, especially among the youth, that we realised it was time to repackage the information," Hoefman said.

With mobile phones used for everything from sending money to a rural relative to paying electricity bills, the number of subscribers in Uganda has boomed and now reaches over 40 percent of the population.

But while using mobiles may be an effective way to deal with HIV issues, the projects are dependent on foreign donors, and with aid budgets dwindling that means alternative ways of financing the projects need to be found.

"We are looking for business models of how we can combine sending out health messages with other messages that people are maybe willing to pay for," Hoefman said, citing market research and advertising as two possibilities.

Uganda has been widely praised for its groundbreaking AIDS policy, which saw condom use promoted and disease rates slashed from over 15 percent in the early nineties to around six percent.

In recent years, however, the HIV rate has started creeping up again as the government, influenced by US evangelists, has placed greater emphasis on policies such as abstinence.

While mobile technology in Uganda can be a useful tool to fight the spread of disease and target vulnerable groups, it cannot mask deeper government failures, health experts say.

"Uganda has a crisis -- it is not speeding up treatment coverage fast enough ... and it is not investing sufficiently in all of the prevention interventions communities need to protect themselves," said Asia Russell, international policy director at Health Gap, an AIDS advocacy group working in Uganda.

"More important is a clear commitment, along with a costed, implemented national plan to end AIDS in Uganda through dramatically scaled up prevention and treatment services."

As for those involved in the ARV text programme, they are searching for new financing to allow them to continue the programme after US government funding for parts of it -- including the ARV alerts -- stopped late last year.

"It can seem like an expensive venture in the short run, but in the long run it turns out to be very cheap," clinic director Guma said.

"But if more people take their medication regularly they become much less infectious, and then in turn we could start to see a drop in the rate of new infections."