The UK’s largest sexual health clinic saw a 40% drop in new HIV infections this year

PrEP and immediate treatment probably both contributing, doctors say; at least one other clinic has seen a similar fall
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The clinic at 56 Dean Street in Soho, central London, the largest sexual health clinic in the UK, saw an unprecedented 40% drop in new HIV diagnoses this year.

A press release from the Chelsea and Westminster Hospital, which runs Dean Street, said that in the period between January and November 2016, the clinic diagnosed 373 new HIV infections. In the same period in 2015, they diagnosed 626 – a fall of 40.4%.

The day afterwards, another clinic, the Mortimer Market Centre, a mile away from Dean Street, said it had seen an even bigger fall – see STOP PRESS below.



In relation to medicines, a drug manufactured and sold without a brand name, in situations where the original manufacturer’s patent has expired or is not enforced. Generic drugs contain the same active ingredients as branded drugs, and have comparable strength, safety, efficacy and quality.


A healthcare professional’s recommendation that a person sees another medical specialist or service.


A sexually transmitted infection caused by the bacterium Treponema pallidum. Transmission can occur by direct contact with a syphilis sore during vaginal, anal, or oral sex. Sores may be found around the penis, vagina, or anus, or in the rectum, on the lips, or in the mouth, but syphilis is often asymptomatic. It can spread from an infected mother to her unborn baby.

risky behaviour

In HIV, refers to any behaviour or action that increases an individual’s probability of acquiring or transmitting HIV, such as having unprotected sex, having multiple partners or sharing drug injection equipment.


A doctor, nurse or other healthcare professional who is active in looking after patients.

The Dean Street clinic accounts for one in nine HIV diagnoses in the UK and one in two diagnoses in men who have sex with men in London.

The fall in diagnoses appears to be real. Dean Street has carried out approximately the same number of HIV tests (in the region of 6250-7500 a month) from January 2015 till now, so this is not due to fewer tests being done.

It also does not appear to be due to declines in risk behaviour or to the clinic attracting more people at lower risk of HIV. Dr Sheena McCormack, Principal Investigator of the PROUD study, who works at Dean Street, told “The decline has been quite significant. Last year we were seeing between 40 and 60 diagnoses every month. This year it has been more like 25 to 40.

“We wondered if the increased publicity about PrEP had resulted in more people coming along who were at lower risk. But if this was the case you’d expect to see fewer other sexually transmitted infections too, and they have not declined.”

Dr Alan McOwan, Dean Street’s Lead Clinician, confirmed this. He told “Syphilis cases have essentially flatlined this year. We saw just over 1000 cases in 2015 at Dean Street and the same number this year.”

This appears then to be a genuine decrease in HIV infections in a population of men who have sex with men at very high risk of HIV. Is this due to improved testing and treatment – or is it at least partly due to pre-exposure prophylaxis (PrEP)?

Sheena McCormack commented: “I think it must be at least partly due to PrEP as we instituted a policy of immediate treatment on diagnosis back in 2012. As a result, 50% of the gay men we diagnose are now themselves in early infection, as incidence assays show, and have less time to pass on HIV. But we didn’t see anything like this happening in 2012.”

Alan McOwan said one practice change Dean Street has made in the last year may have contributed. “In July we instituted the San Francisco model, which means that people walk out of the clinic with their first prescription of antiretroviral therapy (ART) the day they are diagnosed, and now 75% of our HIV-positive clients start treatment at their first HIV appointment.” However, he added, “this started too recently to explain the fact that the drop in infections started a year ago.”

It therefore looks very possible that PrEP may have been a significant contributor to the drop in diagnoses, despite the fact that it is still not generally available in the UK.

On 19 October last year, the website, which informs people about how to buy cheap generic PrEP online, referred its first user to Dean Street in an arrangement whereby the clinic offered HIV and kidney monitoring tests for PrEP buyers (they also offered to test drug levels to see if people were buying genuine PrEP: some results from this scheme were presented in October at the HIV Glasgow conference). This arrangement opened formally this February.

Sheena McCormack commented: “In February we only had about 100 PrEP buyers coming to us. By June we were able to report at the BASHH conference that we had about 400 people in the scheme. We now have about 500 regular attenders. We also have about 75 people attending Dean Street still in the PROUD study out of the 350 or so still remaining.”

Alan McOwan gave a slightly lower estimate of about 350 regular generic PrEP users attending Dean Street but speculated that other people who attend for STIs might be buying PrEP but not telling the clinic. He commented that “the important thing is whether awareness and usage of PrEP is reaching the right people. We now have saturation coverage of it in the clinic: we did a series of YouTube videos of consultants and health advisors talking about PrEP which now play in rotation with other videos on clinic screens. If the ‘nodal’ gay men who have a lot of partners and who would have previously been at the centre of a cluster of infections are now not becoming infected, they are not passing it on to anyone else.”

Greg Owen, who runs I Want PrEP Now, said that his site currently gets about 10,000 unique visitors a month. This was translating into about 500 to 600 personal consultations which had ended up with a referral to Dean Street, or one of the other London clinics with similar arrangements. He said: “Although this is a complete finger-in-the-air estimate, I think about 1800-2000 people are regularly accessing PrEP by buying it online in the UK."

He said that the publicity about PrEP this year, including NHS England’s refusal to provide it in March, and the subsequent successful court action against this decision by the National AIDS Trust, had definitely increased awareness of PrEP among gay men in the UK.

“Up to July this year, we were averaging about 6000 unique visitors a month. In August, we had 12,000, and half of those were on the day that the High Court ruled that the NHS had the power to fund PrEP.

“I think we’ve had good luck, in a way,” he added. “The way that the story has developed in the UK means that it could not have been better designed to catch the attention of the people that most clearly would be targeted by a PrEP awareness campaign anyway.”

Dean Street is not the only London clinic that has seen a fall in HIV diagnoses this year. Dr Ian Williams of Mortimer Market Centre confirmed that they had also seen a fall, and the clinic at St Thomas’ Hospital has seen at least a stabilisation in new diagnoses. More figures will be included on if they become available.

One interesting question this fall in diagnoses brings up is whether it will cause changes to the proposed implementation study of PrEP in England, which aims to enrol a minimum of 10,000 people to start PrEP in the next three years.

Sheena McCormack comments: “These figures may be telling us that targeting PrEP at those most likely to acquire and pass on HIV may have a more dramatic effect than computer models showed – as some of us suspected.

“This implies that the implementation study could also have a more dramatic effect. If so, this raises questions about whether it really needs to continue for three years and whether PrEP should be made generally available sooner.

“This in turn will be dependent on getting it off the ground as soon as possible – and that depends on two things: firstly, that the bureaucracy of running it as a study does not in itself consume too much of the cost, and secondly, that they manage to negotiate a really good price with drug suppliers.”

STOP PRESS: another London clinic sees an even bigger fall in diagnoses

The day after Dean Street's announcement, the Mortimer Market Centre, a mile away from Dean Street (part of the Central and North West London NHS Foundation Trust), announced that its raw data show a more than 50% drop in diagnoses from January to September 2016 when compared with the same time period in 2015. This is despite more HIV tests being performed, and a comparable rate of bacterial STI diagnoses.

Dr Mags Portman, GUM Lead at Mortimer Market, said: “We made a decision to actively support those buying PrEP online early in 2016. This approach has been embraced by all staff from nurses to health advisors to doctors. We ensure that our patients at higher risk of HIV are fully informed about the use of PrEP and have access to safe monitoring alongside good sexual health advice and regular STI screening.

“We remain vigilant for a potential rise in STIs, which has been reported elsewhere, but so far the rate of bacterial STIs in our clinics are comparable to the same timepoint last year. This is very encouraging. Given that the lion's share of HIV is transmitted by people who are recently infected themselves, and who are often untested, we are convinced that PrEP is responsible for the large decreases in new diagnoses being seen.”


I Want PrEP Now:


Dean Street:

Mortimer Market Centre: