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HIV testing

Modelling the scale-down of HIV services in sub-Saharan Africa

19 Sep, 17 | by Leslie Goode, Blogmaster

Search BMJ STI archive, and you will find frequent references to ‘scaling up’, and few – if any – to ‘scaling back’ or ‘scaling down’ (other than Parker/STI).  Who knows if all this may not be about to change, if the US government goes ahead with threats to cut current foreign aid budget ear-marked for HIV by $6.7 billion? How would this affect local HIV programmes?

Walensky & Paltiel  (W&P) model alternative strategies and combinations of strategies for the Republic of South Africa (RSA) and Cote d’Ivoire (CI) to determine which would offer the maximum budgetary return for each year of life lost. Strategies include ‘no new ART’, ‘reduced HIV testing and linking to care’, ‘ART eligibility at a lower CD4 count’, etc.; but all presuppose that commitments to those currently in ART care will be maintained. If scale-back is unavoidable, then it matters how those cuts are implemented; certain combinations of strategies, the authors claim, achieve synergies between strategies such that their combination produces budgetary savings that are greater, per year of life lost, than the total of the two strategies considered separately – for example, ‘late presentation’ and ‘reduced retention’ in RSA. However, ‘no new ART’ turns out to be the strategy that delivers the greatest budgetary savings in an ‘efficient’ manner.

It is hard to gauge the tone of these recommendations – which sound more like a ‘wake-up call’ to the US government than a sober proposal for scale-backs in sub-Saharan countries. Certainly this is not an argument for the long-term cost-effectiveness of any policy for scale-backs, since any short-term savings, they claim, will soon be overtaken by the downstream economic costs of increased HIV transmissions. And even the maximum of savings achievable by these strategies turns out not to exceed 30% of present expenditure. The most efficient alternatives for achieving cuts of 10%-20% will achieve c.$900 and c.$600-900 per every year of life lost in RSA and CI respectively.

In practice, however, it is hard to imagine the necessary cut-backs being achieved in so transparent and rational a manner. At all events, the effect of US cuts to HIV programmes will be presumably be more keenly felt – and will harder to make up for from other (e.g. local) resources – where the proportion of the national HIV budget funded by the US is higher. So, in CI, for example, where 90% of HIV spending comes from international sources, a 10% cut in PEPFAR (President’s Emergency Plan for AIDS Relief) funding would result in a 9% reduction in HIV spending, whereas, in RSA, where most of the funding is self-financed, it would represent a reduction of only 2%. It remains the case, however, that, in absolute terms, that 2% of spending in the RSA is worth $40 million, or double the $20 million saved by the 9% of savings in the CI.

Achieving UNAIDS 90-90-90: More haste less speed?

31 Aug, 17 | by Leslie Goode, Blogmaster

UNAIDS (2014) has set targets for HIV management that seem ambitious, if not unrealistically so  (UNAIDS: 90-90-90): 90% of those living with HIV to know their status; 90% of known HIV+ individuals to undergo ART initiation; 90% of ART+ initiated to achieve viral suppression. A one-year-in report from a large cluster-randomized study of home-based testing and treatment in four Zambian communities, HPTN-071 (Hayes & Fidler (H&F)), recently discussed in this blog (Mountainous challenge of 90-90-90/STI/blogs), suggests that engagement with care may constitute a significant challenge. It gives rates of engagement after six months and one year of care of 42% and 53% respectively. It also confirms what earlier studies (Schwartz & Baral/STIs)  (http://sti.bmj.com/content/early/2016/11/25/sextrans-2016-052773) say about the difficulty of attaining this second target. Estimates as of 2015 for engagement with care in southern and eastern Africa range from 17% to 78% (Wringe & Skovdal/STIs).

Against this somewhat gloomy backdrop, the 2016-17 results from the Swaziland HIV Incidence Measurement Survey (SHIMS2)(http://phia.icap.columbia.edu/wp-content/uploads/2017/07/ZWAZILAND-Factsheet.A4_LR.pdf) from a house-hold based national survey strike a surprisingly hopeful note. 84% of people living with HIV (PLHIV) aged 15 or over report knowing their HIV status; 87.4% of PLHIV knowing their status self-report current use of ART; 91.9% of PLHIV on ART are virally suppressed. Furthermore, rates of response to the survey, at 84.5% (=6,417 eligible households) are impressive. However, PLHIV who are diagnosed but not engaged in care and PLHIV who have become disengaged from care are notoriously difficult to reach (Wringe & Skovdal (STIs)), and likely to be among the non-respondents.

So maybe there is some hope that the UNAIDS targets can be realized by the deadline of 2020 …..

Yet amidst all the anxiety to achieve these targets, a series of qualitative studies reported in the recent supplementary issue of STIs sound a note of caution (STIs: July 2017: 93-3: Understanding the Bottlenecks). This work emphasizes the importance of clients’ personal experiences of health care as a factor in determining likely success in terms of retention in care over time. Among factors likely to have an impact are the painful or disagreeable side-effects from treatment (Renju & Wringe (STIs), or the coercive nature of testing itself (Wringe & Renju (STIs). They also include the attitudes of health-care workers, who are often ‘expert patients’, as well as inappropriate or pressurizing assumptions that test social and moral expectations regarding women’s relationship with men and invoke their moral duty as mothers (Kielmann & Cataldo (STIs). In short, achievement of the benefits of viral suppression requires cooperation of individuals over the longer-term. This in turn depends on trust and good will that are easily forfeited where the pressure to achieve quick results leads health systems to overlook the dimension of personal experience.

HPTN 071 attempts universal home-based HIV testing in sub-Saharan Africa: scaling the mountainous challenge of UNAIDS 90-90-90 target

9 Jun, 17 | by Leslie Goode, Blogmaster

Estimates of 96% for the preventative efficacy of ART against HIV transmission, reported in 2011 by Myron & Cohen (M&C), appeared at last to place long-term containment of the epidemic in our hands.  In the wake of this, UNAIDS: 90-90-90 proposed ambitious targets: 90% of those living with HIV to know their status; 90% of known HIV+ individuals to undergo ART initiation; 90% of ART initiated to achieve viral suppression.  Yet – for all the promise of known ART efficacy – the question remains how easy it will be to realize these targets in practice, especially in those settings (e.g. sub-Saharan Africa) where the impact of the epidemic is at its most severe.

Perhaps less easily than one might imagine, suggest Hayes & Fidler (H&F) – a first (one year in) report of results from HPTN-071.  This is a large cluster-randomized study of home-based HIV testing and treatment in 21 Zambian and S. African communities.  The results derive specifically from four of the seven ‘intervention’ communities situated in Zambia.  Of the c.100,000 consenting to the intervention, and visited by pairs of Community HIV Care Providers (CHiPs), 77% of men and 85% of women ended up knowing their status.  (The rest were presumably not reached, or refused testing.)  The estimated proportion of known HIV positive individuals who then went on to initiate ART was 42% within six months and 53% within 12 months.  Over the first year, the estimated overall percentage of HIV+ adults in the four communities who were on ART rose from 44% to 61%.  Obviously, these results reflect only the first year of the intervention, and CHiPs will revisit participants.  At this stage no estimate of the third UNAIDS target (viral suppression) is possible.  Nevertheless, the results reported by this paper give us a sense of the very considerable challenge that the achievement of the UNAIDS target represents in practice.  Among the difficulties, H&F refer specifically to the difficulty of accessing male participants at their homes, and the very slow rates of initiation to ART.

There are various ways of delivering testing.  Home-based testing has been trialled in populations that would otherwise be very difficult to access – e.g. in indigenous Amazonia (Ribeiro & Benzaken (STIs) (R&B); Benzaken & Peeling (STIs) (B&P).  In the case of HPTN-071, its attraction seems to be the possibility of most easily achieving quasi universal coverage.  At 90-90-90, achieved rates of viral suppression would be 73%; at 80-80-80, they would only be 43% – and the preventive efficacy of ART would be correspondingly reduced.  Yet even the latter target seems ambitious.  So far as the testing is concerned, however, the 90% is within reach – at least in Zambia.  The real challenge will be second (and probably also the third) stage of the cascade.  Other studies indicate that HPTN-071 is not unique in seeing large fall out at this point (see Schwartz & Baral (STIs)).  R&B and B&P point to further problem likely to arise at the stage of rolling out this kind of preventative ART intervention – namely that of maintaining the quality of POCT testing (Benzaken & Peeling (STIs)).

 

The PrEP ‘care continuum/cascade’: how would it look?

8 Mar, 17 | by Leslie Goode, Blogmaster

We take for granted the value of the care continuum (or ‘cascade’), now increasingly seen as the key measure of health system response to HIV (Cassell (STIs editorial)).   The application of this model to HIV has provided a benchmark for evaluation in contexts as diverse as Moscow (Wirtz & Beyrer (STIs)), South Africa (Schwartz & Baral (STIs)) or the Netherlands (van Veen & van der Sande (STIs)).   But could the same model also offer a means of evaluation in the case of other complex sexual health interventions such as PrEP (Pre-Exposure Prophylaxis)?

An on-line soon-to-be-published paper by Nunn & Chan (N&C), building on an earlier attempt by Kelley & Rosenberg (K&R), does precisely this.  An important difference from the earlier paper seems to be the more concrete definition of a larger number of steps (nine as against five) – especially in the central area of ‘uptake’ and engagement in care.  Here K&R define three stages: ‘need for awareness of PrEP and willingness to use it’, ‘need for good access to healthcare’, and ‘need for a prescription for PrEP.  N&C replace these with a more concrete conceptualization of the process in five stages involving: an occasion where PrEP access is facilitated (4); an appointment arising from that occasion where the assessment is performed (5); the prescription of PrEP, where indicated (6); the actual initiation of PrEP (i.e. when the client starts taking the pills) (7).  Also important is N&C’s substitution of two final steps – adherence (8)) then retention (9) for K&R’s single final step of ‘adherence’.  N&C point out that, whereas, with ART, ‘adherence’ is once-and-for-all and secures the ultimate goal of viral suppression, in the case of PrEP, we can envisage multiple trajectories depending on whether PrEP continues to be indicated (e.g. the client may no longer be exposed to risk).  Finally, K&R’s first step – ‘identifying at risk MSM’ – gives way to three: identifying at risk individuals (1), enhancing HIV awareness (2), enhancing PrEP awareness (3).

Is this nine-stage definition of a PrEP cascade overly “complex” (EECAAC2018)?

Answering such a question requires us to reflect on the function that the ‘cascade model’ is called upon to perform.  If the model divides up the total course of an intervention into a series of staged tasks, this is presumably because the health benefit depends on the completion of the whole intervention, yet the accomplishment of each step is necessary to the achievement of subsequent ones.  The idea of the cascade can provide a fair way of evaluating the progress of an intervention before its potential health benefits have been delivered – and can also identify the precise points at which the intervention is failing (i.e. where clients become ‘disengaged’).

It follows that each step should correspond to a potential outcome that is not inferable from previous or later outcomes but is worthy of independent evaluation.  If everyone who accesses PrEP (4) also attends an appointment at which suitability of PrEP is discussed (5), or everyone who adheres to PrEP (8) is also retained in PrEP (9), then steps (4) and (5), or steps (8) and (9), can be merged.  This is not stated in so many words by the authors of the model.  However, I would assume that it must lie at the basis of their thinking.

Revised UK NICE Guidelines for HIV testing: why local prevalence based targeting by GPs and hospitals makes sense

11 Jan, 17 | by Leslie Goode, Blogmaster

November 2016 saw the publication of revised UK NICE Guidelines for HIV testing (last updated 2011) – only a few weeks before the appearance of the annual Public Health England Report: HIV in the UK/2016.  The latter highlights the estimated level of still undiagnosed HIV in the UK (which, at 13,500/101,000, places us 3% short of the UNAIDS 90:90:90 target) and the proportion of late diagnoses (approx. two/five thousand).  It also draws attention to the ‘diversity’ of the epidemic, and the relatively poor levels of diagnosis amongst the 16,500 infected non-black African heterosexuals (approx. 1/4, as opposed to 1/7 for MSM or 1/8.5 for black African heterosexuals).

In the light of these findings, we can appreciate the move in the NICE Guidelines, regarding opportunistic testing in primary and secondary care, towards an approach that, first, makes absolutely clear its basis in regional prevalence rather than any other factor, and, second, is more specific – and more demanding – about the occasions when testing is recommended.  We find a new distinction of two levels of high local risk: high (0.2-0.5%) and extremely high (>0.5%).  This determines whether testing should be offered on specified occasions, namely, in primary care, at registration and the performance of any blood test, and, in secondary care, at admission and performance of a blood test (‘high’ prevalence areas); or whether there should be universal opportunistic testing (‘extremely high’ prevalence areas).  As compared with the 2011 guidelines, an insistence on local prevalence as the determining factor replaces the specification of multiple high-risk groups (e.g. MSM or black Africans).

The danger with routine HIV testing is well illustrated by a 2011 study of screening in 29 Paris emergency departments: Wilson d’Almeida & Cremieux/STIs/blogs.  This trial seems to have spectacularly failed to pick up any HIV infections that would not have been detected even without the intervention.  By contrast, what is proposed by the NICE Guidelines is routine testing in areas of extremely high prevalence.  Of course, patients may still refuse testing (Dhairyawan & Orking/STIs) – and appear to do so all the more frequently where they belong to groups, like non-African heterosexuals, that the authors of the 2016 guidelines are so anxious to include (Mohammed & Hughes/STIs).  Nevertheless, the 2014 HINTS study (HIv testing in Non-Traditional Settings) of the acceptability of routine HIV testing has demonstrated encouraging levels of uptake (c.65%) in UK Emergency Departments, Acute Care Units, Primary Care Centres, and dermatology outpatients (Rayment & Sullivan; see also Mohammed & Hughes/STIs).  Conversely, there is evidence, where primary care is concerned, that practitioners may be capable of missing opportunities for testing even where their patients present with indicator conditions for HIV infection (Agusti & Casabona/STIs).

Responding to the new NICE guidelines, a GPs’ representative stresses the existing workload of GPs and the sensitivity of sexual health issues, but broadly welcomes the new emphasis.

 

 

 

UNAIDS 2016 Report: How a ‘life-cycle’ approach can help the world ‘get on the fast track’ to HIV prevention

7 Dec, 16 | by Leslie Goode, Blogmaster

‘Get on the Fast Track: a Life-cycle Approach to HIV’ is the latest UNAIDS report, following on from the UN Assembly’s 2016 declaration of commitment to ‘Fast Track’ goals for ending the HIV/AIDS epidemic. The major theme of the ‘life-cycle’ appears to owe much to the findings of the South African CAPRISA study – above all, the idea of a transmission cycle between younger (25 year-old) women and older (>25 year-old) men.  Broadly, phylogenetic analysis reveals that the prevailing pattern of transmission is as follows.  Younger women appear to get infected through casual relationships with considerably older men, who have, in turn, been infected by their longer-term partners; in time, the younger women grow up and form longer-term relationships – and the cycle is repeated.  The former group – younger (≤25 year-old) women – appear to be more vulnerable to infection than men of the equivalent age due to complex social factors, and have recently seen only c. 6% declines in annual incidence; older (>25 year-old) men have incidence rates that have remained obstinately high despite all recent efforts to reduce them.  These are best explained by poor rates of testing, integration into treatment, and viral suppression making them a potential risk to non-HIV-infected partners.

Diagnosing a problem is one thing; framing the solution quite another.  In case of the younger women, the dominant factors appear to be structural and societal – e.g. gender inequalities.  These are difficult to address without major social and political change.  The authors suggest a number of prevention tools, including sexual education in schools, the introduction of pre-exposure prophylaxis (PrEP), and social transfers.  However, recent trials of PrEP in sub-Saharan Africa do not bode well for this intervention (STI/blogs/’Failed PrEP trial’; STI/blogs/‘Another failed PrEP trial’); while the evidence for the effectiveness of sexuality education and ‘social transfers’ is far from conclusive (School-based Sexuality Programmes/STI/blogs; STI/Galarraga & Sosa-Rubi; STI/Minnis & Padian; STI/Khan & Khan).  However, in the case of the other group – i.e. older men – the obstacles to HIV prevention (poor rates of testing and viral suppression) may be less intractable, and the report proposes a number of very practical measures that could help, including: distribution of self-test kits through female partners attending ante-natal clinics (STI/blogs/’Partner-delivered STI testing’); simplifying ART regimens so individuals have to take just one tablet a day; shifting from CD4 count testing to viral load testing.

The report also has much to say about other phases of the life-cycle, as well as about ‘key populations’ (estimated 45% of new infections).  Regarding the latter, the authors report the stability, or even rise, in new infections amongst sex-workers, drug-users and MSM. They emphasize the negative impact of criminalization of key populations and same-sex relations (73 countries) (see STI/blog/’HIV criminalization’/; STI/blog/’Health workers violate human rights’), the very low levels of domestic funding (on average, only 12% of total spending on MSM prevention), and the relatively young age of many in the ‘key populations’.  The authors recommend ‘comprehensive’ programmes for these populations incorporating access to a range of health care programmes, such as the Red Umbrella programme for sex workers in South African, and the ‘Targeted Strategy Plan’ for the transgender population in Lima, Peru.

 

Partner-delivered HIV self-testing through antenatal clinics: the way ahead for partner notification in low-resource settings?

23 Nov, 16 | by Leslie Goode, Blogmaster

A recently published, Kenya-based, randomized controlled study (Masters & Thirumurthy/STIs) (M&T) evaluates a novel intervention that appears to combine in a fresh way elements of various innovative interventions for HIV prevention.  Recently published studies (e.g. Kissinger/STIs; Estcourt & Cassell/STIs) have explored the potential of ‘expedited’, or ‘accelerated’ partner therapy – where the partner of an index STI-infected individual is offered therapy through the infected individual directly, without a clinic attendance, or with only a telephone interview. They have also evaluated the benefits of ‘self-testing’ for HIV (e.g. Pai & Dheda/STIs).  The intervention trialled by M&T – partner delivered HIV self-testing – combines elements of these two types of interventions.  A third crucial element is that it takes advantage of the unique opportunity offered by antenatal and postpartum clinics in low resource settings (see Azeze & Haile/STIs; Sombie & Dabis/STIs; Ganiyu & Mason/STIs) to make contact with HIV-infected individuals who might otherwise have little access to health services.

In M&T’s study, participants attending antenatal and postpartum clinics (ANC) who were assigned to the intervention arm of the study (n=284/570) were offered two oral-fluid-based HIVselfing kits, one for themselves, one for their partner.  Discussion about HIV, self-testing, couple testing, and awareness of partner’s result were subsequently reported by index patients at monthly follow-up meetings over a three-month period.  This ANC-based, partner-delivered HIV self-testing intervention was evaluated against a control group (n=286/570) who were given an invitation card for conventional clinic-based HIV testing and encouraged to distribute the card to partners.

The primary outcome was reported partner HIV testing which was 91% for the intervention as against 52% for the control.  The intervention looked at couple testing (42% difference between intervention group and control), and awareness of partner’s HIV status (difference=39%).  0% participants in either group reported intimate partner violence (IPV) as a consequence of HIV testing.

Concerns around interventions of this kind tend to centre upon two things.  First, the absence of any direct contact between partner and health services, and consequent loss of an opportunity to test for the full range of STIs and help ensure integration into treatment (Estcourt & Cassell/STIs).  Second, worries as to the likelihood of IPV related to testing.  On the first, concern may be less where the self-test is for HIV, and the partner misses out on testing for the other STIs (Kissinger/STIs), than it would be where, as in many non-African settings, the self-test would generally be for Chlamydia or gonorrhoea and HIV could remain undiagnosed.  Regarding IPV, the authors note its lack of association with testing in the study (despite base-line reported rates of 27%).  They also point to the large proportion of eligible declining to participate (715/1,315).  This – taken together with zero cases of IPV – they interpret as a possible indication of the ‘agency’ of these women, and their capacity to make their own judgments regarding the possible impact of participation on their relationships.  The problem of ensuring engagement with care among those self-tested for HIV, however, is one that the authors acknowledge as still needing to be resolved.

As for the study itself, a primary limitation is self-reporting.  But here the authors note that misreporting is hardly likely to account for the differences between intervention and control arm – which is the evidence that the authors principally emphasize.

 

How Mobile Technology Can Lead to Improved Care of STIs – by Julie Potyraj

16 Aug, 16 | by Leslie Goode, Blogmaster

Blog by Julie Potyraj, Community Manager, Milken Institute School of Public Health at The George Washington University

e: jpotyraj@publichealthonline.gwu.edu

As we move into an era where our phones do everything from lowering the temperature in our homes to arranging a ride, it comes as no surprise that these devices also offer a new way to meet and engage with potential sexual partners. Along with the rise in popularity of dating apps, there has been an increase the incidence of sexually transmitted infections. In 2014 the CDC received the highest number of reports in history for chlamydia, syphilis, and gonorrhea in the United States. The challenge is to figure out a way to use technology to safeguard our sexual health in addition to meeting new partners.

In an effort to encourage online daters to get tested, a study published in Sexual Health posted advertisements for free HIV test kits on the dating website Grindr. In exchange for providing personal information about their health status and behaviors, participants received a free test kit. Not only did this intervention encourage HIV testing, but the study also showed an increase in the number of young men seeking treatment. Even a few of the volunteers who helped with the study became aware of their statuses.

The Grindr study shows that the privacy and comforts of home testing can be a desirable alternative to visiting a doctors’ office. Providing this alternative could potentially increase the number of people seeking testing for STIs. Improved testing technology used in tandem with the convenience and range of a mobile device introduces the opportunity to connect huge numbers of people with diagnostic interventions. The more people who get tested, the more data there is available. If this trend continues, we can anticipate an incredible expansion in electronic reporting, STI surveillance, and the use of this data in health informatics.

Mobile technology contributes to the collection of big data, which is defined as complex data sets that are so large that they cannot be evaluated by traditional data management tools. With better surveillance of STIs, medical providers can reach and identify commonly overlooked demographics by tracking trends to improve diagnostic care, interventions, patient outcomes, and cost of care.

More widely available data about STI outbreaks and incidence rates could help health care providers to make more informed medical decisions. For example, a care provider who identifies chlamydia from a patient’s urine could use big data to inform her decision about what type of antibiotic to prescribe. She may find there is an increasing incidence of azithromycin-resistant chlamydia in her city or state. Her awareness of this emerging trend would lead her to prescribe her patient with doxycycline instead; providing better medical care through informed treatment decisions.

The use of mobile technology can broaden epidemiologic surveillance and trend analysis of STI infections, offering knowledge to care providers that is otherwise unobtainable. More people using STI diagnostic interventions leads to the more people being tested and in turn better access to STI statistics. Mobile technologies, and health interventions that make use of them, can contribute to the collection of timely, relevant data. The analysis and interpretation of this data offers the possibility of improving health care quality and outcomes for patients.

Julie Potyraj

Is the UK meeting its national guidelines for HIV testing of MSM?

9 May, 16 | by Leslie Goode, Blogmaster

The potential role of frequent HIV testing in curbing the HIV epidemic among the MSM population has long been recognized. The introduction of the strategy of ‘opt-out’ testing in the UK (2007), as in other countries at around the same time, brought a steep rise in testing, followed by stabilization (McDaid & Hart (STIs); Saxton & Hughes (STIs) (for New Zealand); Heijman & Prins (STIs)  (Netherlands)), and may now ‘have reached its limit in maximizing routine uptake’ (McDaid & Flowers).  Nonetheless, amongst UK MSM at least, HIV incidence is not declining.  UK guidelines currently recommend annual HIV testing for MSM, and three-monthly testing for those ‘at higher risk’.  But how far are these goals being met?  An audit conducted in UK GUM clinics (Desai & Suillivan/STIs) was reassuring;  but a recent (2013) cross-sectional survey of gay bars in Glasgow reports levels of HIV testing over the previous six months of only 37%, and a relatively high proportion of ‘high-risk’ takers figuring among those who had never tested (OR: 0.51)( McDaid & Flowers (STIs)).

Last month saw the publication of study (McDaid & Flowers (M&F)) based on data from three cross-sectional surveys – Glasgow/Edinburgh gay commercial venues; an internet-based Scotland-wide survey; London gay social venues – and including 2409 MSM in total.  Frequency of testing was reckoned over a two-year period, and classified as ‘one or less’, ‘two or three times’, or ‘four or more times’.  On this basis, the study estimates the proportion testing annually at only 54.9%  – and the proportion of those reporting higher risk unprotected anal intercourse (UAI) (=37.8% of the total) who tested four or more times at only 26.7%.  So neither in respect to MSM in general, nor in respect to those ‘at high risk’ are the UK national guidelines being met.  Moreover, involvement in higher risk UAI – unlike number of sexual partners and AI partners – turns out not to be significantly correlated with the highest rates of testing; while more of those reporting higher risk activities claimed to have tested as a result of a perceived risk event, rather than as part of a regular check-up.  The authors conjecture the episodes of higher risk UAI may have been less frequent events (albeit reported by a third of participants) after which the participants, being risk-aware, took appropriate preventative action.  This seems a plausible interpretation.

Studies of HIV testing in other countries published in STI Journal seem to show a broadly comparable situation, with testing levels for MSM and high-risk MSM consistently falling short of respective national guidelines.  Thus Saxton & Hughes (STIs) in location based surveys in Auckland report levels of MSM annual testing rising slowly to 50% in 2011; while Guy & Hellard (STIs) surveying testing in Australian GP clinics give figures for annual testing by MSM, and high-risk MSM, of 35% and 15% respectively as of 2010.  As for the US, Katz & Stekler (STIs) report levels of annual testing of 77%, but, as the location of this survey was GP clinics, an appropriate UK comparator would be the study reported by Desai & Suillivan/STIs, which reports levels of 92%.

In their recommendations M&F stress the importance of reducing the known barriers to HIV testing, and also draw our attention to the key role that testing will have in facilitating the effectiveness of future PrEP interventions, given the need for participants in PrEP to have an accurate knowledge of their HIV status.

 

 

Responding appropriately to differentials in HIV care outcomes – are local answers needed?

12 May, 14 | by Leslie Goode, Blogmaster

The recent discovery of the preventative potential of anti-retroviral therapy (ART) (STIs/blog/modelling ART impact)  throws into sharp relief the challenge represented for the US by the very inadequate proportion of its 1.2 million HIV+ citizens (<30%) who are virally suppressed.  Nunn & Mayer  use new geographical mapping tools to bring home forcibly the epidemiological dimension of the problem by visualizing the association which HIV+ incidence/mortality show with social status and ethnicity as reflected in residence.  The picture that emerges is of an enormous concentration of the problem in certain very circumscribed neighbourhoods.  To give just one example of what is best conveyed in the diagrams (figures 1 & 2), age-adjusted death rates rise from <11.2 per 1000 people living with AIDS (PLWHA) to 19.4-32.5 per 1000 PLWHA as one passes from a predominantly white neighbourhood with large gay population and high rates of HIV/AIDS (≥2142 per 100,000 population) to the predominantly Afro-Caribbean neighbourhood of Harlem.

For Nunn & Mayer (N&M), these visualizations raise the question whether either (1.) the allocation of resources to metropolitan areas, or (2.) the nature of the strategies employed by public health interventions, reflects the very geographically focussed nature of the problem of HIV/AIDS incidence and mortality.  Their response to the epidemiological dimension of the problem revealed by their mapping tools is to urge the importance of implementation research as a vital component of HIV initiatives.

N&M’s emphasis on viraemia suppression, rather than just HIV incidence, accords well with their insistence of the epidemiological importance of the local dimension.  Retention in care is a factor that is presumably amenable to initiatives at local level – whereas HIV incidence may owe much to transmission through sexual contacts external to the community (STI/blog/Grabowski & Gray).

Their message is in line with increasing public health interest over recent years in “program impact evaluation methods that take account of the complex interactions among interventions and between intervention packages and the context into which they are introduced” (STIs/Aral & Blanchard).  There is surely a strong argument in favour of designing interventions to take place within an evaluative framework allowing a reflection on the kind of program mix likely to be most effective in a given context.  On the other hand, N&M may be in danger of undervaluing the potential of interventions of a non-localized character that act on the socio-economic determinants of the HIV problem, and especially non-retention in care – for example, the wider provision of medical insurance (STI/blogs/ObamaCare).  It would be interesting to see how far a geographical mapping of the incidence of other health problems in New York or Philadelpia coincided with N&M’s mapping of HIV/AIDS mortality.  How far is the effect of “micro-epidemics”, conjured up by epidemiological language, just a reflection of socio-economic determinants that produce identical results wherever they happen to be present?

 

 

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