Life expectancy for people with HIV has increased by an average of 13 years since the late 1990s thanks to better HIV treatment, a study says.
Researchers said it meant HIV was now effectively a chronic condition such as diabetes, rather than a fatal disease, the Lancet reported.
The team, involving Bristol University staff, looked at over 43,000 patients.
The study found a person now diagnosed at 20 years old could expect to live for another 49 years.
But the Anti-retroviral Therapy Cohort Collaboration, which includes scientists from across Europe and Northern America, warned this was still short of the life expectancy for the wider population which stands at about 80.
Anti-retroviral treatment for HIV consists of drugs which work against the infection itself by slowing down the replication of the virus in the body. This method of therapy was introduced in the 1990s, but has since become more effective and better tolerated.
The researchers looked at life expectancy during three time periods after the introduction of the drugs - 1996-9, 2000-2 and 2003-5 - in high income countries.
Just over 2,000 patients died during the study periods. They found that while patients aged 20 diagnosed in the 1990s could expect to live another 36 years, that had increased by 13 years by 2003-5. During the middle time period, life expectancy stood at an extra 41 years.
Lead researcher Professor Jonathan Sterne said: "These advances have transformed HIV from being a fatal disease, which was the reality for patients before the advent of combination treatment, into a long-term chronic condition."
He added the development was a "testament" to the success of the anti-HIV drugs.
However, researchers warned those diagnosed later in the course of the infection had a much shorter life expectancy.