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Safer sex in the treatment era

Published: 01 March 2011

There is mounting evidence that reducing viral load through HIV treatment may be one of the most effective ways of stopping onward transmission of HIV. But how should this influence what we tell patients about prevention?  Dr Dan Clutterbuck, sexual health consultant in Lothian and the Borders in Scotland and chair of the writing group for the new BHIVA/BASHH safer sex guidelines, explains what they say. 

Draft national guidelines on safer sex advice, produced by the British Association for Sexual Health and HIV (BASHH) and the British HIV Association (BHIVA), will be released for general consultation this month.1

Advising on safer sex is a routine part of sexual health services, an expected part of encounters between patient and healthcare worker, whether the patient is having a routine check-up for sexually transmitted infections (STIs) or has just been told they have HIV. 

The content and format of that advice, though – what to say and how to say it - is much less clearly defined than other aspects of clinical care for people living with, or at risk of, HIV and other STIs.

What to say was simple in the early days of the HIV epidemic: “use a condom”. Short of avoiding sex altogether, nothing else worked. Then the UK cut the transmission rate from mothers to babies tenfold between 1993 and 1998 by giving HIV-positive pregnant women antiretrovirals (ARVs).

From then on, it was clear that ARVs would play a big role in prevention. How to integrate information on treatment, viral load and infectiousness into more traditional safer-sex advice has been complex ever since, for professionals and patients.

The new guidelines provide advice to healthcare workers on the ways in which this topic might be introduced and managed with clinic attendees and those at risk of HIV infection, formalising the content of advice on avoiding STI and HIV transmission. There is a section providing advice specifically for people with HIV, in a more concise format than existing guidelines.2 We hope the guidelines will help to ensure consistent advice is given in non-specialist settings as well as in HIV clinics, and to people regardless of HIV status.

Safer-sex advice works

Let’s not forget that traditional safer-sex advice works. A review of 18 meta-analyses,3 each one synthesising results from many studies, found an average increase in condom use of 34% in all the groups studied and a decrease of about 13% in partner numbers. This resulted in an average reduction of 26% in STIs – a spread of different interventions stopped one-in-four STI infections.4

It’s harder to measure reduction in HIV infections directly: it’s a fairly rare event and you need large studies. But one intensive course of intervention in gay men reduced their chances of getting HIV by about one-sixth.5

This may be less than you were expecting, though with more intensive support, quite dramatic reductions in risk behaviour have been noted. In the recent iPrEx trial6 of the antiretroviral drug Truvada as a preventive measure against HIV (known as pre-exposure prophylaxis, or PrEP) in men who have sex with men (MSM), for instance, the average number of sexual partners men had in the previous three months went down from 18 at screening, to seven at the start of the study, to just two while on it. Similar results were found in a previous study of PrEP in women.7

Safer-sex interventions are an essential element of any HIV prevention strategy, whether in addition to ARVs or in isolation. We don’t know, however, what the ‘minimum effective dose’ is: the effectiveness of a single episode of advice-giving is unclear.

Condoms and treatments

Advice needs to be clear and unambiguous. So the new guidelines contain straightforward, evidence-based recommendations on condom effectiveness, breakage, size and the use of lubricants.

Recommendations on partner reduction, the provision of post-exposure prophylaxis (PEP), and the effect of male circumcision are also included.

One problem is how to turn science into patient-friendly advice for individuals. Areas where lack of evidence makes it difficult to formulate clear statements include the reduction in risk with HIV treatment, the transmission risk attributable to oral sex, and advice on serosorting and negotiated safety (see opposite).

Initially, the writing group wondered whether to compare the effectiveness of condom use with that of viral load suppression in people with HIV, but decided not to make a direct comparison between the two. Although experts agree condoms are virtually 100% efficacious in preventing HIV if used perfectly,8 many studies have found that the effectiveness within groups of consistent condom users is around 80%,9 reflecting the frequency of condom failure and errors in real life.

Evidence for condoms’ effectiveness in preventing HIV transmission during sex between men is particularly sparse, although few would doubt that they are highly effective. There is also evidence that 100% use, amongst people at risk of HIV, is quite rare: one study found that only 5.1% of STI clinic attendees used condoms every time they had sex in the year following an STI clinic visit.10

In contrast, there is growing evidence for the effect of ARVs in reducing HIV transmission risk. Reports of HIV transmission from people with undetectable plasma (blood) viral loads are confined to a small number of cases.11,12

The new guidelines say:

Taking effective antiretroviral therapy and having a quantitative plasma viral load below the limit of detection of currently available assays significantly reduces the risk of HIV transmission.

The much discussed ‘Swiss statement’,13 in which a group of senior HIV doctors in Switzerland said that certain groups of patients on effective HIV treatment “are not” infectious, was clarified after publication to say that transmission risk with undetectable viral load was in fact comparable to that with consistent condom use.

In line with the Swiss statement, the new UK guidelines add that:

The risks are increased with reduced ART adherence or the presence of STIs in either partner. The risks can be reduced by using condoms and having regular sexual health check ups.

They recognise, though, that couples might consider stopping condom use for various reasons: a long-term monogamous relationship, or planning a pregnancy, for example, but recommend detailed counselling for couples intending to discontinue condom use.

Although there is no evidence yet of widespread behaviour change as people become aware that treatment reduces infectiousness,14 it is increasingly likely that decisions about disclosure, condom use, and shared responsibility for avoiding transmission will depend on such awareness. These decisions will not always occur within regular relationships, in which extensive counselling is possible.

Greater collective and community understanding of the level of relative risk is needed, both of the uncertainties that apply to the evidence for condoms, and of exactly what we know about viral load suppression. Professionals advising people with HIV or at risk will require increased knowledge and risk literacy, as will their clients.

Although there is currently insufficient evidence to support a blanket public health policy of ‘treatment as prevention’,15 starting treatment early to reduce the risk of onward transmission may be appropriate as part of a risk-reduction approach for some people. The guidelines recommend:

Discussion regarding the early initiation of antiretroviral therapy to reduce the risk of HIV transmission should be considered as part of safer sex counselling for some people living with HIV.

Negotiated safety and serosorting

Alternative risk-reduction strategies are recognised and, where evidence exists for them, included: serosorting, for example, (only having sex, or unprotected sex, with people with your own HIV status). The same thing applied to people whose last test was HIV-negative is often called ‘negotiated safety’. We do cite evidence that serosorting may reduce the incidence of new HIV infections in MSM16 but warn that there may be an increase in other STIs.17

The recommendations say:

Negotiated safety and serosorting should be discussed with those who are known or suspected to be unable or unwilling to maintain 100% condom use. Detailed information and advice should be tailored to the individual’s circumstances to maximise the health improvement benefit.

In these areas guidance is potentially contentious; the guidelines go on to add:

MSM should be advised that serosorting is less effective than consistent condom use but more effective than non-selective non-use in preventing HIV acquisition or transmission.

Oral sex

The guidelines cover other areas of advice too numerous to mention here, but one other potentially hazardous area we enter is to try to give some guidance on the risk of HIV acquisition through oral sex.

Epidemiological evidence on this risk is difficult to verify,18,19 because few people exclusively have oral sex, but it is regarded as not zero, in untreated individuals at least.  Experience and evidence suggests that condom use for oral sex is (very) low in all groups studied.20,21 Recognising that recommending routine condom use for oral sex is probably unrealistic, the draft guidelines state:

Safer sex advice should include information on the risks of oral sex, recognising that individuals must make an informed decision on the level of risk that is acceptable to them, and supporting pragmatic alternative risk reduction techniques.

The guidelines recognise that other STIs are more contagious via oral sex, to the extent of transmission being possible to the genital partner (the one who ‘has it done to them’) as well as the oral partner (the one who ‘does it’): 

The risk of transmission of bacterial and viral STIs including HIV applies to both oral and genital partners, but the risk to the genital partner is thought to be considerably lower. The risks of transmission associated with oral sex are lower than for unprotected vaginal or anal sex except in the case of HSV 1 [the cold sore herpes virus]. 

The guidelines don’t try to resolve the issue of zero or non-zero HIV transmission risk for oral, vaginal or anal sex with people on ARVs with an undetectable viral load, restating that HIV transmission with undetectable viral load is “extremely rare”. 11,12


HTU asked some readers what they thought of the guidelines.

Paul Clift, HIV patient representative at King’s College Hospital in south London and a member of the BHIVA Guidelines Subcommittee, says:

It really is important that the guidelines emphasise the positive effect of programmes to improve condom use. The effect of this work is often understated. The hard financial cost of one HIV infection, including all expenses incurred, is at least half a million pounds, but because this money is not seen ‘up front’, it becomes easy for a cost-cutting government or commissioning consortium simply not to spend on necessary prevention.

Dr Clutterbuck’s comment that “professionals advising people with HIV or at risk will require increased knowledge and risk literacy, as will their clients.” is very important. I hear a lot of confusion about the effect of condoms and of viral suppression in the patients I represent, and I’m concerned that those who are educationally or intellectually capable, and who are Western-orientated in their cultural references, will be able to make this work for them, while those who cannot will be left behind and possibly placed in greater danger of inadvertent onward transmission of HIV and possible criminal charges.

Including patients in writing guidelines would help “turn science into patient-friendly advice for individuals”, as BHIVA has done before. A patient representative should be included in necessary further work on translating advice intended for healthcare workers into advice comprehensible to patients.

Silvia Petretti, patient representative on the BHIVA Executive, says:

I have definitely positive feelings about a greater recognition of the role of treatment in reducing risk and the freedom given to serodifferent couples to negotiate levels of risk they feel comfortable with. I do fear though, that as messages around safer sex become more complex, people may feel confused - but over-simplification is patronising. People need appropriate support and counselling to make informed choices, especially as there is a lot of complex information to process and to apply on sexual choices. How this support will be available with the current cuts in the NHS taking place is a cause of anxiety.

I hope the oral sex section will distinguish clearly between vaginal and penile oral sex (cunnilingus and fellatio) because it does often get very confusing.

Ben Cromarty, of North Yorkshire AIDS Action, says:

Although the article says that safer-sex advice works, and goes on to quantify this, I am not so sure that this has been the case over the past decade. The number of HIV and most STI infections acquired in the UK, in both MSM and heterosexuals, has risen steadily, year on year. This suggests that there has been little change in behaviour.

Condom use is a real issue. For some people, the lack of spontaneity is enough to discourage condom use…comments like “it destroys the moment” are commonplace. For these people – and there are many – even repeated messages about condom use are unlikely to change behaviour. Other risk-avoiding strategies may be used by people with HIV - “I don’t come inside him” or “I am now always passive, never active” – in an attempt to minimise risk. Perhaps the most effective message might be (for someone who is HIV-positive) to go onto treatment and maintain an undetectable viral load.

For other folks, though, condom use is no big deal – however, these may by definition be the folks who don’t catch STIs and don’t go to GUM clinics. When they do turn up, advice given to first-timers at a GUM clinic may need to be much more detailed than that given to someone coming for a routine sexual health screen.

Robert James, patient representative at the Lawson Unit clinic in Brighton, says:

This document is a very impressive one, evaluating the merits of a much wider range of different safer-sex methods than I expected. 

The ‘safe’ option for these guidelines would be to stick to saying 100% condom use and ignore the problems of achieving this. This is particularly so because the Crown Prosecution Service (CPS) has defined reckless sexual behaviour as ignoring “safeguards [that] satisfy medical experts as reasonable”.  This means, if this is what clinicians advise their patients on safer sex, doing something different could be seen as a sign of reckless sexual behaviour in the eyes of the CPS and make a person liable to prosecution.

Some things do read strangely: partner reduction is recommended for oral sex but not anal or vaginal. Partly this is because of evidence for one and lack of it for another but it does look odd though and implies it is OK to shag lots of people as long as nobody sucks anyone off!

Serosorting for HIV is acknowledged to have an impact, even if nothing like as much as condom use, but increases other STI infections. 

The issue of HIV treatment and condoms is probably the only place it feels a little cautious.  Treatment alone comes with a caution that it is not always effective, but condom use does not, and the ‘Swiss Statement’ is posed as a problem, not a solution. I think they bottled out of exploring whether treatment is as good as condoms, rather than whether treatment means people are uninfectious. I do think, though, that in circumstances where using condoms is impossible (e.g. in a violent relationship with someone who refuses) they could have recommended HIV treatment as the best safer-sex method. Such specifics might help some very vulnerable people who could end up in court.

What do you think?

The guidelines are draft and open for consultation until 31st May 2011. Feedback is welcomed to ensure that the UK professional and community consensus is appropriately reflected.  The final guidelines will be supported by a document detailing the evidence and any new evidence identified in feedback.


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This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.
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This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

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