A perspective in PLOS Medicine suggests that people with HIV who achieve viral suppression with antiretroviral therapy can avoid sexual transmission of HIV without using condoms, a significant study that lends hope that the "treatment as prevention" method can stop the spread of the HIV infection.

"This research embodies the idea that what is undetectable is untransmissible -; the new paradigm of U=U," said Jeanne Marrazzo, lead author of the perspective. "This is great news for the study of HIV transmission and warrants further research as they continue to seek a way to control and arrest the HIV epidemic."

Research shows that people who use TDF-FTC as a preventive measure can avoid HIV infection, a method that is becoming more popular in the U.S. and is increasingly being rolled out in countries with major HIV epidemics. This gives researchers hope that this prevention modality will yield long-term control in the spread of HIV, even where condom use rates are low.

However, while HIV transmission is unlikely when antiretroviral therapy sustains viral suppression, a new challenge is at hand: the increasing rate of sexually transmitted infections that are accompanying the decline in condom use. These STIs include chlamydia, gonorrhea, and syphilis, and all have increased markedly, particularly among men.

Marrazzo stresses that the idea is to confront this reality and have a dialogue about what it means and to discuss alignment of research and funding priorities to ensure that both HIV and STI rates decline. She explains that it is critical that progress is made to halt the spread of any and all sexually transmitted infections, in real-world settings, and there is a need to develop effective solutions to do so.

"Based on this research, a new conversation about the alignment and prioritization of HIV research funding and public health policy needs to take place, with an emphasis on community engagement through the promotion of sexual health and the development of comprehensive approaches to studies in STIs moving forward," Marrazzo said.

"We need to engage in dialogue in communities to ensure that it is understood how HIV and STIs are spread and managed, and what we can continue to do to make sure rates decline. That's how we will ultimately beat this epidemic." Marrazzo also notes that education about HIV needs to continue, as anxiety about contracting HIV has lessened.