A trial on the effectiveness of anti-retroviral drugs,commonly used in treating HIV in preventing sexual transmission of the virus to young unmarried women have shown that the drugs do not work.
The research, Vaginal and Oral Interventions to Control the Epidemic (VOICE) began in September 2009 and is set to to have its last phase ending in August this year.
It involves 5 029 participants, 630 of them Zimbabweans.
The drugs were being administered as either vaginal gel or an oral tablet.
Announcing the results on Monday, VOICE project director Dr Nyaradzo Mgodi said the reason why the three test products namely, tenofovir gel, oral tenofovir and oral truvada proved to be ineffective was the lack of adherence.
"All the results were not statistically significant. All the products did not work to prevent HIV in the population because the women were not using the study product.
"We found out that less than 40 percent were using the study product and that less than a third had indications of the drugs on their hair, blood or vaginal area," she said.
"An analysis of blood samples from a subset of 773 participants (including women who acquired HIV) found adherence to product use was low across all groups, drug was detected in 29 percent of blood samples from women in the Truvada group, 28 percent of samples in the oral tenofovir group and 23 percent among those in the tenofovir gel group.
"In sharp contrast, adherence to the product use was calculated to be about 90 percent based on what the participants themselves had reported to trial staff and on monthly counts of unused gel applicators and leftover pills," the report stated.
Dr Mgodi said what was most shocking was that relatively older married women were better in using the product than young single women who were at higher risk of contracting the disease.
"We are now considering looking at psycho-social problems that the women might have encountered because for some reason they did not use the product.
"In the Zimbabwean context 60 percent of the women had completed their secondary education which suggests higher levels of literacy hence there is a need to engage women to help us as scientists to address the situation," Dr Mgodi said.
Previous researches, on the use of Tenofovir in South Africa's KwaZulu Natal Province had found that it reduced the risk of HIV by 39 percent.
According to the report, seven Zimbabweans became infected with HIV during the study, nearly twice the rate that investigators had envisaged when the trial was designed.
HIV incidence, which reflects the number of women who became infected for every 100 participants in a given year, ranged from 0,8 in Zimbabwe, 2,1 percent in Uganda to seven percent in South Africa.
Condom use is one of the readily used and recommended ways of preventing HIV but women have over the years been faced with the challenge of negotiating for their use with their partners.
It was hoped that if the drugs became successful, women who account for 60 percent of adults with HIV in Sub-Saharan Africa, would have a more convenient strategy of protecting themselves.