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Can we ensure adherence to STI treatment guidelines in a world threatened by antimicrobial resistance?

27 Jul, 15 | by Leslie Goode, Blogmaster

Sexual health care in the UK has traditionally centred on specialist GUM (genitor-urinary medicine) services.  Since the turn of the twenty-first century primary care has played an increasing role, however.  The 2012 Health and Social Care Act is in line with this tendency, with most GP (general practitioner) practices now being commissioned to provide level 1 STI screening.  Questions have recently been raised about the conformity of care provided by GPs to national guidelines, established for the UK by the British Association for Sexual Health and HIV (BASHH) (Trotter & Okunwobi-Smith (STIs)).

So what is currently the extent of GP involvement in the UK in care of infections previously dealt with by specialist services (i.e. Chlamydia and Gonorrhoea), and how is this impacting on the treatment of these conditions?  Wetten & Hughes (W&H), in a population-based study using data from the UK Clinical Practice Research Datalink (CPRD), provide the answers to both questions.  As regards the role of GPs, the proportion of Chlamydia cases they diagnosed varied over the study period (2000-2011) between 16% and 9%, and appeared to be on a downward trajectory, while the proportion of Gonorrhoea cases fluctuated between 6% and 9%.  As for the quality of care received in general practice, there is a marked disparity between the two conditions.  Whereas, in the case of Chlamydia, 90% were prescribed a recommended therapy, of the patients presenting with Gonorrhoea only 40% received the recommended anti-microbial regimen.  Ciprofloxacin continued to used (42% of prescriptions in 2006, 20% in 2011) long after the 2005 change in national treatment guidelines favouring cephalosporins.

These findings appear to corroborate the concerns expressed by UK patients in another recent study that their expectations for appropriate in-house care or referral to specialist services were not always being met (Sutcliffe & Cassell (STIs)).

The issues raised by these UK studies around the adherence to prescribing guidelines by generalist physicians are not, of course, unique to the UK.  Similar concerns have been voiced in studies based on data emerging from the BEACH (Bettering Evaluation and Care of Health) programme in Australia (Santella & Hillman (STIs); Freedman & Mindel (STIs); Johnston & Mindel (STIs), as well as in studies from more diverse settings (Khandwalla & Rahman (STIs)).  Quite apart from the need to optimize patient outcomes and reduce the burden of infection in the population, the problem of adherence by generalists to guidelines raises more general questions.  The issue of antimicrobial resistance has prompted recent national interventions to “steward” our remaining antibiotic defences (Gonorrhoea antimicrobial resistance (STIs/blog).  Such policies will evidently depend on the adherence to guidelines, including by generalists – especially in settings where they are responsible for much of STI care.  In a world where Gonorrhoea – and perhaps one day Chlamydia – is set to become increasingly hard to treat, the problem of ensuring the conformity of generalists to universal standards of treatment is unlikely to go away.

 

 

Myth or reality? Are social media triggering an explosion in sexually transmitted infections?

23 Jul, 15 | by Leslie Goode, Blogmaster

On the whole, where STIs are concerned, social media have tended to be considered as a potential force for the good in public health, offering a new resource for the management of HIV patients, or opportunities for disseminating health messages via peer education (Swanton & Mullan (STIs); Peer group education (STIs/blog)).  Recently, however, there have been a number of studies that have drawn attention to the negative implications of social media.  Last June a study by Beymer & Morisky (STIs), based on data on MSM attendees at the Los Angeles Gay and Lesbian Centre, concluded that, among the 7,000 participants, those who had used geo-sexual networking apps to meet up with a partner had greater odds for testing positive for gonorrhoea (OR 1.25) or chlamydia (OR 1.37) than those who employed in-person methods.

Recently, this more negative side has been receiving ever more attention in the US, especially in connection with HIV transmission.  A yet unpublished but widely publicized study, Agarwal and Greenwood (A&G), investigates hospital attendances for asymptomatic HIV (including acute and silent phases of the infection)  in Florida over the period 2002-2006 when the piece-meal introduction of the digital commerce platform, Craigslist, appears to have greatly facilitated on-line social transactions through its “casual encounters” forum.  It has also offered researchers the chance to record what they describe as a “natural experiment”, as successive counties have experienced the effects of entry into the platform.  A&G estimate the health “penalty” of entry into Craigslist at a 13.5% increase in attributable HIV infections – equivalent in financial terms to an additional burden of $592 million on the State of Florida.   This finding has recently been cited in connection with the precipitous rise in STIs in Rhode Island recently reported in an official Rhode Island Goverment press release and in the press coverage (Huffington Post) – 79% in syphilis; 30% in gonorrhoea; 33% in HIV over the year 2013-2014.

But A&G are concerned with more than estimating the magnitude of the effect.   The recent paper also claims to be the first study to attempt to determine exactly where that penalty of increased HIV infection due to social networking is actually falling – a question that is evidently of great interest to public health specialists who need to be able to target their interventions.  On the face of it, this is something of a puzzle.  HIV appears to be most heavily concentrated amongst the very sectors of the population who are most digitally disadvantaged.  So what could be going on?  To answer this question, A&G seek to disaggregate the Craigslist effect by ethnicity, income-level (as determined by enrolment in Medicaid) and gender.  What emerges from their analysis is that the effect of Craigslist entry is contained almost exclusively within the Afro-Caribbean (as opposed to Latino or “Caucasian”) population.  A&G seek to explain this apparently disproportionate penalty accruing to the digitally disadvantaged.  They argue that the “digital divide” is probably not “binary”, but more like a continuum.  We should not, in other words, necessarily think of “digital disadvantage” – at least for an important proportion of the disadvantaged – in terms of the total absence of access or skill.  It is therefore conceivable that it should be associated with a negative effect, i.e. the increased HIV incidence following Craigslist entry.  “Digital disadvantage”, they argue, is likely to be a matter of the limited capacity to utilize on-line resources for “welfare-enhancing activities” rather than a total unavailability of those resources.

 

Incidental gonorrhoea screening in the general population via dual NAAT is no benefit

12 Jun, 15 | by Leslie Goode, Blogmaster

Fifer & Ison (STIs) express concern over the use of the “dual” nucleic acid amplification tests (NAATs) for the detection of chlamydia and gonorrhoea in the context of chlamydia screening in the UK.  Additional testing for gonorrhoea, when the real target is chlamydia, does not necessarily confer an additional net benefit.   This is because even a high specificity test such as Cobas 4800 (Perry & Corden (STIs); Rockett & Limnios (STIs)) will generate a high proportion of false positives when the infection tested for has extremely low prevalence, as in the  case of gonorrhoea in the general population.  And the potential disbenefit of the additional test in terms of the psychological impact, and the impact on relationships, of false positive diagnoses could easily outweigh the medical benefit represented by the diagnoses which are accurate (Dixon-Woods & Shukla (STIs); McCaffery & Wardle (STIs)).

The potential impact of the adoption of the dual NAAT as a stand-alone test – if not confirmed by further testing using either a second NAAT or else culture – is illustrated by a recent Australian study published in the Medical Journal of Australia (MJA).  Chow & Fairley perform a retrospective analysis of insurance and notification data from Melbourne over the years 2008-2013.  They seek to demonstrate that the apparent rise in identified gonorrhoea cases amongst the general female – non-indigenous – population (from 98 to 343) is at least partly an “artefact” of the growing employment by laboratories of the dual NAAT.  They do this by eliminating the alternative possibility of a genuine increase in gonorrhoea in the general population.  To this purpose they use their data to investigate changes in the proportion of positive dual NAAT gonorrhoea diagnoses to the number of dual NAAT test ordered, over the period during which dual NAATs were being introduced.  They also investigate rates of positive gonorrhoea diagnoses over this period at a “sentinel” clinic in Victoria where culture alone was used as a means ofgGonorrhea diagnosis.  They find that the proportion of positive dual NAAT diagnoses in Victoria remained relatively constant over time (around 0.2-0.3%), as did the proportion of positive culture diagnoses at the Melbourne clinic (around 0.4-0.6%).  Of 25 untreated women who had a positive NAAT result for gonorrhoea and were referred to the Melbourne clinic, only 10/25 were confirmed by culture.  The authors comment that this is in line with what might be expected in the light of the published specificity of the various NAAT tests employed.

C&F recommend that laboratories suppress gonorrhoea diagnoses from the dual NAATs.  An MJA editorial in the same issue questions the feasibility of this.  Instead, the editors propose that the NAAT should, in the case of Gonorrhoea, be used as either a triage, with positive diagnoses confirmed by culture, or as an add-on where high prevalence populations are first tested by culture.  They also consider the possibility of confirming the initial NAAT with a NAAT using a different target.  However, they come down in favour of retaining culture in the diagnostic pathway on account of its value as a means of assessing resistance.  They also question whether even the double NAAT would guarantee adequate predictive value in very low prevalence populations.

Evidently, further studies are required.

Why Tanzania seems unlikely to meet UNAIDS targets for HIV/AIDS prevention.

12 Jun, 15 | by Leslie Goode, Blogmaster

The UNAIDS 90-90-90 Target has set the goal that, by 2020, 90% of the HIV infected should know their status, 90% of those diagnosed should be in treatment, and 90% of those in treatment should achieve viral suppression.  The  UNAIDS GAP Report (2014) presses the need for countries to achieve a major redeployment of effort and resources towards tackling HIV among at-risk populations with a view to achieving that target (UNAIDS (STI/blog)).

Redeployment, a report by Congressional staff delegates on a visit to Tanzania hosted by the Infectious Diseases Society of America’s (IDSA) Global Education and Research Foundation gives a detailed account of the practical problems facing the attempt to make such ambitions a reality on the ground – even where UNAIDS recommendations are embedded in official government planning policy.  Evidence from visits of the staff delegates to Dar-es-Salaam, Zanzibar and Mbeya in the rural highlands is illustrated with well-chosen photographs.   These problems fall into three general categories.

First, there is a human resource problem.  At present, there is a 65% vacancy rate for health-care positions in the public sector.  According to the government figures, health workforce capacities have steadily declined from 67,000 in 1994/5 to 54,245 in 2002 to 48,000 in 2015.  The PEPFAR (President’s Emergency Plan For AIDS Relief) operational plan attributes this in some measure to gaps in Tanzania’s education capacities with large classes and poorly trained teachers, leading to pupils leaving school without adequate study, problem solving and analytic skills.

As regards redeployment of these limited resources in line with UNAIDS recommendations, this is hindered by the fact that at risk groups may be criminalized (e.g. drug-users, sex workers, MSM) and are certainly stigmatized.  Much of the outreach to them is through civil society organizations.  While the government has policies to support and defend their efforts, there is little in the way of financial investment.  Civil society organizations are hampered by the largely voluntary nature of their workforce, and the absence of adequate data concerning the size and whereabouts of at-risk populations (though it is estimated that between 2010 and 2015 the number of IDU rose from 25,000 to 50,000).  The prison population seems to be altogether inaccessible.

Thirdly, HIV transmitted to children born to infected mothers is often ignored, and the number of adolescents dying of AIDS has risen by a third since 2005.  This is partly because stigma surrounding a disease associated with IDUs, sex-workers MSM prevents parents from seeking diagnoses for their children.  The situation is not helped be the frequently poor state of record-keeping with no digitalization and folders “jammed into, stacked on top of, and spilling out of record cabinets”.

Though no doubt inadequate, data on “at risk” populations is not altogether absent.  Studies published in STI journal relevant to populations in specific places visited by delegates include an evaluation of surveys of MSM in Zanzibar, Haji & Kibona (STIs), and a discussion of the socio-demographic context of the epidemic in Mbeya, Riedner & Groskurth (STIs), focussing on female bar-workers.  As a poor but high-mobility rural population, Mbeya appears to share some socio-demographic characteristics with Mzanza province in the NW (bordering Lake Victoria) which has figured in a number of studies at the beginning of the last decade.  A number of these focus on barmaids as a particularly high-risk population (Hoffmann & Hoelscher(STIs); Boerma & Mwaluko (STIs); Bloom & Boerma (STIs)).

 

Increased HIV infectivity in the acute phase of infection may be a less important factor in HIV transmission than we thought

12 Jun, 15 | by Leslie Goode, Blogmaster

Assessing, as far as we can, the preventative impact of ART on HIV transmission dynamics is evidently very important – both to inform judgments about ART initiation (Wayal & Hart (STI); Cohen (STI)), and also, at the policy level, to be able to evaluate the possible preventative gains of ART scale-up (Shafer & White (STI); Boily & Mishra (STI)).   One important piece of the jigsaw is the impact of ART on sexual behaviour.  This has been discussed by a number of recent studies (Wayal & Hart (STI); Hogben & Ford (STI); Shafer & White (STI)).  Another piece of the jigsaw is the impact of ART on HIV infectivity.  Of particular concern here are the relatively high levels of infectivity that occur in the period immediately after infection.  In view of this, investigators have stressed the importance of the earliest possible initiation of therapy, if the full preventative benefits of ART are to be enjoyed (Cohen (STI)).

The recent study, Bellan & Meyers (B&M), addresses itself to this second, important but potentially less easily investigable piece of the jigsaw. They observe that investigators have tended to proceed on the basis of the known relationship between viral load and infectivity. Empirical evidence of relative infectivity of acute versus chronic phases of the infection is practically unobtainable, for various reasons.  For a start, newly-infected individuals are rarely diagnosed in the acute phase and, if infected by stable partners may provide no evidence on onward tradition; if susceptible non-infected partners are at risk, then, clearly, ethical guidelines dictate that further transmission be stopped – not investigated.  According to B&M, most subsequent studies have relied for direct epidemiological measurement of acute phase infectivity and duration on a retrospective cohort in Rakai, Uganda (Wawer & Quinn; Hollingsworth & Fraser). B&M reassess previous analyses of this evidence.  They find significant bias – especially in two areas.  The first has to do with the neglect of the contribution to total risk of couples who were censored from the cohort owing to couple dissolution, loss to follow-up or study termination.  The second concerns the extent to which some of the estimated difference in risk between the acute and chronic phases may reflect heterogeneity in the risk behaviour of those couples entering the study sero-discordant, as against those entering it sero-concordant negative.

The findings of B&M are intriguing. They argue that combined effect of these sources of bias in earlier analysis of the Rakai evidence has been enormously to inflate estimates of relative acute phase – relative to chronic phase – HIV infectivity. B&M estimate the relative hazard of transmission during acute phase at 5.3, the acute phase duration at 1.7 months, and the “extra-hazard months” contributed by the acute phase (a measure adopted by the authors in order to ensure comparability of study results) at 8.4. Previous estimates give levels of increased infectivity due to acute phase which are equivalent to between 31 and 141 hazard months. If the results of B&M are confirmed in subsequent studies, the preventative gains of ART scale-up could be greater than hitherto supposed.

Achieving HPV herd immunity cost-effectively. When does it make sense to allocate resources preferentially to boys?

23 Apr, 15 | by Leslie Goode, Blogmaster

Recent empirical studies of HPV vaccination have provided evidence that marginal vaccination costs increase with coverage.  Let us take into account – they argue – not just the vaccine price, but the cost of education and outreach programmes that would be needed so as to reach the yet unvaccinated population.  If we do so, we are likely to find that raising the vaccination rate for pre-adolescent girls, let us say, from 40-41%, proves considerably more expensive than raising it from 20-21%.  This, in turn, raises the question whether – given the achievement of herd immunity is the ultimate goal – resources are necessarily best allocated when directed to the female rather than the male pre-adolescent population. Could it even be that – at certain levels of coverage and a certain rates of increase in marginal vaccination cost (for girls and for boys) – resources might be more effectively allocated to the vaccination of pre-adolescent boys? Ryser & Myers in a recent study seek to model the impact of marginal cost increase in order to answer this question.  In the case of US, at least – with rates of vaccination standing currently, for girls and boys, at, respectively 37% and 13.9% – they argue in cost benefit terms for re-directing resources to boys.  However, the question is no doubt relevant to other countries in which HPV has been introduced, but levels sufficient for herd immunity, have not yet been achieved.

Optimal allocation of new resources as between girls and boys for a given level of vaccination is indicated in the diagrams on p.40.  Marginal vaccination cost increase is estimated at a higher, a lower, and zero level.  What is striking is the radically different patterns of optimal allocation between girls and boys in those three scenarios.  At the very least, the results challenge the orthodoxy of the superior cost benefit of female vaccination. They also indicate the importance of further empirical research into marginal vaccination cost increase.

The limitations of the study are largely due to the assumption of a closed sexual network of 14-18 yr old heterosexual adolescents.  The attempt is made to factor in the impact of various complicating factors, such as the assortativity of vaccine uptake with sexual activity, the likely presence of additional relationships between females inside, and older males outside, the network, and asymmetric vaccination cost curves as between girls and boys.  But the most serious limitation was beyond the power of the study to address.  This is the restriction of the modelled network to heterosexual relations, and the exclusion from consideration of a large number of HPV-related conditions such as anal and oro-pharyngeal cancers which have higher incidence among MSM and HIV-infected individuals (Lawton & Asboe (STIs); English & Pourbohloul (STIs)).  One wonders, therefore, whether the case for male HPV vaccination is not a great deal stronger than might appear from this paper.  At all events, a case is made that, even when these conditions are excluded, a greater allocation of HPV vaccination resources to males may be justifiable – e.g. currently in the US.  For the impact of the recent extension of the HPV vaccination programme to males in Australia (the first country to have taken this step (2013)), see Korostil & Donovan (STIs).

Can financial incentives help address the problem of HIV lost-to-follow-up in the US?

21 Apr, 15 | by Leslie Goode, Blogmaster

An article by Skarbinski & Mermin, discussed in my recent blog, Skarbinski & Mermin (STI/blogs), throws into sharp light the problem of the 45.2% of the HIV/AIDS infected population who are diagnosed but lost to follow-up.  According to their estimate this group are responsible for 61.3% of transmissions.  Various local attempts have been made to address this problem through more “wrap-around” approaches to health care (Bocour & Less (STI/blog)), or through computer assisted self-interviewing (Dombrowski & Golden (STI).  Another approach is the use of financial incentives.  Relatively small-scale and local experiments in various forms of conditional cash transfer have been described by a number of studies recently featured in STIs.  These have aimed, for example, to reduce STIs and pregnancy among Latino youth in San Francisco (Minnis & Padian (STI)), to encourage HIV-infected men to bring their wives for testing in Pakistan (Khan & Khan (STI), to incentivize villagers to remain HIV-free in Lesotho (Bjoerkman-Nyqvist & Svensson (STI)), or to promote syphilis testing amongst indigenous groups in Edmonton, Canada (Gratrix & Talbot (STI)).

Yet what role could financial incentives play in the broader context of mainstream HIV management in the US?  Could they help to address the problem of retention in HIV care across the range of HIV care settings?

A recent US study, HPTN 065 (TLC-Plus) reported at the 2015 Conference on Retroviruses and Opportunistic Infections (CROI) addresses this very question.  It involved two-year RCT in a total of 37 testing sites in Bronx and Washington DC., randomized to an intervention and a control arm.  The intervention offered incentives for both linkage-to-care, and viral suppression.  For linkage-to-care, the incentive consisted in the issue to HIV diagnosed of a $25 coupon redeemable when the participant returned to have blood taken for laboratory tests, and a $100 coupon redeemable when he/she returned for test results and to discuss a long-term care plan.  For viral suppression, it took the form of the issue of a $70 gift card to patients taking medication at the end of every three months if they had an undetectable viral load.  Over the duration of the trial, 1,061 coupons were given for linkage-to-care, and 40,000 gift cards were dispensed to 9,153 patients for viral suppression.

Disappointingly, no overall increase was observed in intervention compared to control settings, either in linkage-to-care or in the proportion of patients achieving viral suppression.  However, the intervention brought significant improvements in viral suppression and continuity of care (completion of four out of five possible visits for tests in last 15 months) within certain specific care settings.  In particular, these were: care settings where <65% of the patients were achieving viral suppression at the start of the study (improvements of 10% overall, 13% as measured in the last three months of the study); small-scale care settings (improvements of 13% as measured in the last three months, and of 19% overall in continuity of care).  The investigators conclude that there may be a role for financial incentives in specific health care settings.

Indiana State ban on Needle Share programmes faces challenge of an IDU-fuelled HIV spike

20 Apr, 15 | by Leslie Goode, Blogmaster

In 2011 18.5% of HIV infections in the US were attributable to intravenous drug-use (IDU) – a significant proportion (Lansky & Wejnert (STIs)).  The issue of IDU fuelled HIV transmission has been brought forcibly to the attention of Americans in the last few weeks by the recent HIV outbreak in Scott County, Indiana, US.  This local epidemic appears to have been the result of the recreational use of the opiate, Opala. The number of infections has continued to rise, reaching a new peak of 130 this last week (Indystar/needle exchange; npr/Indiana’s HIV spike).

The effectiveness of public health interventions amongst IDU, including needle exchange programmes is well-established. Recent studies in Russia and East-European contexts (Vagaitseva & Demyanenko (STIs); Boci & Bani (STIs)), where IDU accounts for greatest proportion of infections,  have also come to very positive conclusions about their cost-effectiveness (Demyanenko & Vagaitseva (STIs).  They have also considered ways of improving uptake among drug-users (Boci & Hallkaj (STIs).  Sadly, in 23 states of the US – as in Russia and some East-European countries – traditional legal restrictions on needle exchange programmes remain in force (LawAtlas/US).  Indiana just happens to be one of these US states.  Its governor, who has had to authorize a short-term moratorium on the legal restriction of needle exchange in response to the outbreak, just happens to be Mike Pence, a republican who is known for his especially hawkish views on social issues (see “US Republicans prepared to put the poor at risk” (STI/blogs)) and favours continuation of the ban.

Needless to say, an order authorizing the temporary suspension of the restrictions on needle exchange was issued last month.  A needle-exchange programme has distributed 5,300 clean needles to drug-users since 8th April when it began its activities.

Unfortunately, however, the temporary suspension is due to expire on 25th April.  It also applies only to Scott County. Health experts are pushing legislators to allow needle exchange in neighbouring counties of Indiana, where high levels of HCV indicate a high risk of similar outbreaks.  On Monday, a joint Senate and House Legislative Committee will consider a measure, authored by Ed Clere, a representative from a neighbouring county, to authorize local public health and law enforcement authorities to work together to start their own need exchange programmes. But Governor Pence has threatened to veto the measure.  He declines to explain his position in public, but is said by Senate President, David Long, to believe that needle exchange programmes lead to greater drug use (News & Tribune/Indiana’s needle exchange bill).

Retention in care rather than diagnosis may prove the ultimate challenge for US HIV response

25 Mar, 15 | by Leslie Goode, Blogmaster

The real challenge which the US HIV/AIDS epidemic poses for the US public health services is not simply to achieve higher levels of diagnosis – but, far more than that, to improve linkage to, and retention in, care.  This claim is hardly controversial. But it is thrown into stark relief in a recent study by Skarbinski & Mermin, which estimates the number of HIV transmissions attributable to non-retention in care for 2009.

The authors employ the notion of a five-phase “care continuum”.  Using population data from the National HIV Surveillance System and medical data from the National HIV Behavioral Surveillance System and the Medical Monitoring Project, they estimate the number of HIV transmissions occurring at each phase.  The phases in the continuum are: (1) infected, but undiagnosed; (2) diagnosed, but not retained in care (attending at least one visit to a medical care provider Jan. – April 2009); (3) diagnosed, retained in care, but not given ART; (4) diagnosed, retained in care, prescribed ART, but not virally suppressed; (5) virally suppressed.

The reduction in attributable transmissions achieved for those diagnosed but not retained in care (phase 2), as compared with those who remain undiagnosed (phase 1), is 19%.  (It is probably due to a decrease in HIV-discordant unprotected sex).  But the reduction achieved for those who achieve viral suppression (phase 5), as compared with those who remain undiagnosed, is 94%.  In estimating the epidemiological impact of these reductions, we need to factor in the percentage of the infected population at each phase.  The large proportion (45.2%) of the HIV infected who are diagnosed but not retained (phase 2) explains the very high proportion of total transmissions (61.3%) attributable to this phase.  By comparison, only 30.2% are attributable to the undiagnosed (phase 1), and 2.5% to the virally suppressed (phase 5).  The low epidemiological impact of those at phases 3 and 4 is due to the relatively low proportion of those infected who remain in these phases.

The message, then, is that achieving greater success in retaining the HIV diagnosed in care may prove the key to combating the epidemic at population level.  Of course, diagnosis remains the indispensable first step.  But the potential gains of diagnosis will be only very partially experienced, so long as such a large proportion of those diagnosed are not retained in care.  Of course, improving retention in care may constitute a somewhat different – and perhaps more difficult – challenge for the US health services from diagnosis.  The specific problems of the US health system in this regard are discussed by Sherer (STI), and the characteristics of individuals “lost to follow up” by Haddow & Mercey (STI) and Lee & Gazzard (STI).  Local attempts to address these problems through a more “wrap-around” approach to health care in the US are described in my blog Bocour & Less (STI/blog) (see Bocour &  Less).  There has also been interest in the computer assisted self-interviewing in order to engage those lost to care (Dombrowski & Golden (STI)).

Reported 86% effectiveness for MSM PrEP by PROUD study makes this intervention a viable option for UK health services

25 Mar, 15 | by Leslie Goode, Blogmaster

The Conference on Retroviruses and Opportunistic Infections has recently taken place.  At that event the UK PROUD (PRe-exposure Option for reducing HIV in the UK: immediate or Deferred) study of pre-exposure prophylaxis (PrEP) for MSM reported its results, prior to publication in the coming months.  The headline figure is an astonishing 86% for the reduction of risk of infection in the intervention group.  Hitherto, results of PrEP trials, largely conducted in Africa, have often been disappointing.  This is probably on account of poor adherence (VOICE D( STI/blog); Haberer & Bangsberg (STI/blog); Hendrix & Bumpus (STI/blog)).  The good result achieved here is no doubt attributable to good adherence.  It demonstrates, as these earlier trials have not, the true effectiveness of PrEP.

The UK trial included 545 participants at 13 practices. 276 were randomized to receive PrEP immediately, while the remaining 269 received it after a year.  Earlier PrEP trials have been blind and placebo-controlled.  But this design had the advantage of demonstrating the effectiveness of PrEP in real life. The participants were aware if they were taking the active drug and could have changed their sexual behaviour accordingly.  Given one of the major concerns around PrEP is that of risk compensation – i.e. taking advantage of the protection of PrEP to engage in more risky behaviour than they would otherwise (Marcus & Grant (STI/blog); Baeten & Celum (STI/blog)) – this was a valuable aspect of the trial.

In the period to October 2014, there were 22 HIV infections – 3 in the immediate, and 19 in the deferred group.  This gives us the headline figure of 86%.  At this point, ethical considerations dictated that the study design be changed so all participants received PrEP from then on.  Initially, this study was intended to be a pilot, and to be followed by a larger scale trial.  The decisiveness of the interim findings, however, led to cancellation of that further study.  (For an interesting commentary on the need for researchers to keep pace with changing ethical parameters, see Cohen & Sugarman (STI/blog)).  Cost-effectiveness analyses are apparently underway.  No details are given in the report.  But evidently the high effectiveness observed in the study will allow investigators to present a far more positive case for PrEP than has been warranted by earlier trials (see Borquez & Hallett (STI); Gomez & Hallett (STI/blog); Cremin & Garnett (STI)).  They are also working with stakeholders on how PrEP services could be commissioned across NHS and local authorities.

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