U.S.-led research in Cameroon on a drug which inhibits HIV has recently run into controversy, with activists saying tested prostitutes are being victimized.
Dozens of HIV positive patients wait in a military hospital in the capital Yaounde for a free dose of anti-retroviral drugs.
This program run by Doctors Without Borders has run without any problems.
But another program, to test the effectiveness of the drug Tenofovir in preventing HIV infection, is causing what Cameroonian journalist Roger Taakam says some activists are calling a "humanitarian catastrophe."
He says the scandal erupted last week when a French-produced program aired on African television, alleging Cameroonian prostitutes were being used to put their lives at risk for the benefit of the trial.
A Yaounde-based activist for a non-governmental organization dealing with ethics and AIDS, Calice Talom, says everything started badly when participants were rushed to sign a consent form in English most of them probably didn't understand.
"We are not sure that someone who wants to give his informed consent who wouldn't understand or read English could do so because the fact that we are bilingual doesn't mean all Cameroonians can speak and understand French and English," said Calice Talom.
Activists also say the 400 participants in the trial - all of them sexually active HIV negative young women with multiple partners - aren't being given proper condoms or counseling during the trial, and too little care if they get infected. Half of them are being given a placebo instead of the drug, which has also caused concern.
The drug, sold under the name Viread by the U.S.-based company Gilead, is already widely used in developed countries as part of HIV treatment.
The trial's coordinator in Cameroon, Anderson Doh, says it has proven highly effective in preventing infection of a virus that is similar to HIV in animals.
"Animal experiments, especially the monkeys, have proven conclusively that this drug is quite efficient in protecting animals, even 24 hours after they get pricked or injected by the virus," said Mr. Doh.
This trial is being run to see if it can prevent transmission of the virus that causes AIDS in humans.
Mr. Doh says it's normal to have half the participants using a placebo, and that they need to be a high-risk population.
He also disputes comments that economic reasons pushed Gilead to use African prostitutes.
"This is not true because right in the [United] States, in Atlanta and San Francisco, similar studies using the same drugs are being carried out. So we want a high-risk group and at the end of the day anyway it is the same group, if tomorrow the results are conclusive, who will benefit most from the drug," he said.
The Cameroonian government is now reviewing whether the trial has respected ethical norms as agreed to when it started in June 2004.
Similar studies, all being run by a U.S.-based group called Family Health International and funded by the Bill and Melinda Gates Foundation, are taking place in nearby Nigeria and Ghana, but so far without controversy.
In a recent report, the United Nations said Africans accounted for more than 25 million of the nearly 40 million people worldwide with HIV-AIDS.