New HIV diagnoses in the UK have fallen to their lowest level since 2000, figures show.
There was a 17% drop in the number of new diagnoses last year, declining from 5,280 in 2016 to 4,363 in 2017, Public Health England (PHE) said.
Numbers have reduced by more than a quarter (28%) since 2015 and are at their lowest since 2000, when there were 3,989.
The number of new diagnoses among gay and bisexual men dropped by 31% between 2015 and 2017, from 3,390 to 2,330, the figures show.
Professor Noel Gill, head of the STI and HIV department at PHE, said UK prevention measures are having a “significant impact”.
Uptake of HIV testing among men most at risk is high, PHE said, and uptake of anti-retroviral therapy (ART) has also increased.
The drugs keep the level of HIV in the body low and prevent it being passed on.
Ian Green, chief executive of Terrence Higgins Trust, said: “HIV treatment has undoubtedly played a role in this decline.
“Now, when someone is diagnosed, they are encouraged to immediately start treatment.
“This enables them to more quickly achieve an undetectable viral load, which means HIV can’t be passed on.”
He added: “Today’s drop in new HIV diagnoses among some communities in the UK clearly shows we have the tools to end the HIV epidemic in this country.
“But, rather than patting ourselves on the back, we need to redouble our efforts, work harder and get to zero HIV transmissions.”
Overall, 42% of people were diagnosed at a late stage of infection, which is linked with a 10-fold increased risk of dying within a year, the figures show.
Mr Green said the figure remains “worryingly high”.
Professor Gill said: “The most common way of getting HIV in the UK is through having sex without a condom – so consistent and correct condom use with new and casual partners stops you getting or transmitting HIV and other STIs.
“If you think you have been exposed to HIV it is easy to get tested so, if positive, you can start treatment as soon as possible.”
Steve Brine, public health minister, said: “HIV is a devastating and life-altering disease.
“Today’s figures mean we are well on our way to eradicating it once and for all but we have not an ounce of complacency.
“Our commitment to prevention has led to more people getting tested and almost every person with a diagnosis is now in treatment – meaning they are unlikely to pass the virus on to someone else.
“I am committed to ensuring that we deliver on our promise to reduce the number of people contracting HIV even further.”