A new drug for treating Human Immunodeficiency Virus could help reduce the chances of the disease being transmitted through sexual activity, one of the four ways in which it can spread (the others being through blood, through breast milk and infected syringes)

Researchers from the Bellvitge Biomedical Research Institute, Barcelona, evaluated the speed at which the new antiretroviral drug, Dolutegravir, is able to reduce the viral load, or the amount of HIV in semen.

Semen is considered to be a reservoir of the virus and drugs so far have not be able to access it easily, said the press release issued by the Insitute.

The study was published in the Journal of Infectious Diseases. An editorial published in the same issue of the journal said that of the estimated 2.1 million new HIV infections worldwide in 2015, an overwhelming majority were sexually transmitted, most often through semen.

The researchers measured the viral load in the blood and semen before starting treatment, then at three days, seven days, 14 days, one month, three months and then six months. They found out that the viral load drop goes down quickly in the first few day and a weeks.

The current treatment is able to decrease blood viral load within six to nine months but still 5%-25% of the patients maintain detectable levels of virus in their semen.

Therefore, in case of couples where one is HIV positive, the person who is HIV negative is advised to take anti-HIV drugs as a preventive measure, along with using condoms. This research may help arrive at better prevention options for such couples.

The authors of the study were Dr Daniel Podzamczer, Dr Jordi Niubó from Bellvitge Biomedical Research Institute, Dr Angela D Kashuba of the University of North Carolina’s Center for AIDS Research and Dr Javier Martínez-Picado of IrsiCaixa AIDS Research Institute, Barcelona.