Finally CDC announced that if someone is HIV positive, has undetectable viral load and is taking ART (Antiretroviral Therapy) the person is unable to stransmit the virus to a HIV negative one. Basically they said that the change is somewhere between negligible and zero for more than 2500 exposures. Negligible means that the chance is so low there is no need to worry about it.
According to the official statistics if someone has high viral load the changes for infection to uninfected partner are 2500:1. However the majority of medical providers do have old and outdated information. Unfortunately most of the campaigns and messages about the HIV transmission risk are based on outdated research with old information.
It’s very important to keep in mind that in order to have undetectable viral load, a HIV positive person needs to take ART as prescribed. A lot of infected people can’t reach undetectable load, because of a limited treatment access. ART takes care of the active (replicating) HIV and the virus puts itself to a latent mode in which it is hiding and waiting. It’s also very important to keep in mind that if someone has reached undetectable load and stops taking ART the virus will start replicating again.
Understanding that successful ART treatment can reduce the risk and transmission rate is very important for finding a cure or at least reducing the new infections. Recent publications suggest that we might be only a step away from finding a cure, but the research is still in early stages.