U=U stands for
Undetectable = Untransmittable, a message based on more than two decades of accumulated evidence that a person living with HIV who has
undetectable viral load does not transmit HIV to their partners.
Over the past year, hundreds have joined the growing list of health experts and organizations around the world to endorse the
Undetectable Equals Untransmittable Consensus Statement.
Based on analysis of more than 16,000 people who reached an
undetectable viral load * with antiretroviral therapy (below 50 copies), researchers in the United Kingdom (Great Britain) estimate that the rebound rate (chance of a later detectable viral load) falls close to 1% per year after 7 years of viral control.
HIV patients with
undetectable viral levels like Sheen who regularly take their medication "cannot actively transmit HIV, and we should not treat them that way," Dr.
If there is not enough time to attain an
undetectable viral load, however, it is reasonable for the patient to be on HAART for as long as possible before amniocentesis.
However, the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF) remains hopeful that the scientific breakthrough that allowed the child's HIV levels to remain
undetectable for more than two years will continue to help researchers understand how to control HIV and ultimately develop a cure.
When Congress first approved the
Undetectable Firearms Act in 1988, lawmakers could not foresee that a quarter century later anyone with access to a 3-D printer that can be purchased for less than $1,000, an Internet connection and some cheap, readily available materials can make a fully functional plastic handgun that can fire multiple shots.
For patients with chronic hepatitis C virus infection, achieving an
undetectable viral load cut the risk of death by 45% and the risk of liver-related adverse events by 27%, in a large study.
The data showed that 78% of treatment-naive patients and 76% of patients who had responded inadequately to or relapsed after prior treatment with P/R had
undetectable virus at week 12 (cEVR) while receiving setrobuvir plus P/R, compared to 56% and 44%, respectively, for patients who received placebo plus P/R.
This has made it possible to suppress the viral infection to
undetectable levels in some people, giving years of life.
In early 2008 Swiss doctors issued a statement that in certain circumstances, people taking HIV treatment with an
undetectable viral load are not infectious to sexual partners.
This study focuses on characterization of
undetectable bridging faults applied to induced wired-AND/wired-OR fault model.
undetectable - not easily seen 
undetectable - barely able to be perceived; "the transition was almost indiscernible"; "an almost insensible change"