Aspirin does not carry the stigma associated with other anti-HIV drugs.
An affordable, globally available drug - low-dose aspirin - could help prevent HIV transmission, scientists say.
HIV infection rates remain unacceptably high, especially among young African women.
Researchers including those from University of Manitoba in Canada tested the effect of acetylsalicylic acid (ASA or aspirin) and other anti-inflammatory drugs on HIV target cells in a group of Kenyan women who were at low risk for HIV.
The pilot study, published in the Journal of the International AIDS Society, built on existing knowledge about the role of inflammation in HIV transmission.
Transmission of the virus requires a susceptible target cell in the human host. Activated immune cells are more susceptible to HIV infection than resting cells. It is known that inflammation brings activated HIV target cells to the female genital tract.
The researchers found that Aspirin was the most effective anti-inflammatory drug. It reduced the number of HIV target cells in the female genital tract by 35 per cent.
The reduced number of HIV target cells in the women who took aspirin approached the level found in Kenyan women at high risk of HIV contraction who have remained uninfected for many years.
"Further research is needed to confirm our results with aspirin and test whether this level of target cell reduction will actually prevent HIV infections," said Keith R Fowke from University of Manitoba.
"If so, this could be a strategy for HIV prevention that is not only inexpensive, but easily accessed globally. People living in poverty are disproportionately at risk of acquiring HIV. We need prevention approaches that are affordable and immediately available," said Fowke.
The goal is to provide a new tool in the HIV prevention arsenal that would be used together with other approaches to reduce HIV transmission in high-risk populations, Fowke said.
Study participants were given the same daily low dose of aspirin that is commonly used for long-term prevention of cardiovascular disease.
Participants said they liked that aspirin does not carry the stigma associated with other anti-HIV drugs, which could mean it is more likely to be used regularly.