Rapid testing in Australia?

An intensive policy and practical panel discussion about the possibility of rapid HIV tests being rolled out in Australia

PHILLIP KEEN (AFAO) — in Australia, rapid HIV tests are not approved for use at screening points or by consumers, but there are three approved for use as reference tests in laboratories (although none are actually using them).

The Therapeutic Goods Administration licenses tests and how they may be used, and has not licensed any rapid tests for use in screening or by consumers.

The National Reference Laboratory undertakes technical assessment of testing technologies including a comparison to other tests currently available — and the longer ‘window period’ of rapid tests currently means they fail on this comparison.

The draft Sixth National HIV Strategy does mention the possible use of rapid testing, so there is hope there may be a policy change in favour of their approval in future.

IRYNA ZABLOTSKA (formerly NCHSR, now NCHECR) presents behavioural surveillance data on HIV testing among gay men in Australia.

Australia has incredibly high testing rates — more than 90% of gay community attached men have ever tested, by comparison to UK (82% from a sexual health service sample) and 70% in the US. However, about 10% have never been tested, so today Iryna focuses on factors predicting that a respondent on the gay community periodic surveys 2007/8 has never been tested.

The biggest predictor is have no or only one sexual partner, between them including more than 50% of the never-tested men, although 5-6% (from memory) had 50+ partners.

Younger age also strongly predicts never having tested, with 70% never having tested under 19 years of age, even those who have had more than 10 sexual partners in the past six months.

Non-European men and ATSI men are 3-4% more likely never to have tested (but Iryna does not present data on their sexual activity rates).

In terms of frequency of testing — a key issue for judging whether gay men are “conforming to guidelines”, to use Iryna’s language — among men who had 10+ partners (last six months) 61% tested in the past six months, 16.6% 7-12 months, and the rest had not tested in the past 1-2 years or longer.

Iryna notes 14% of non-positive men had STI tests but not an HIV test, and she describes this as a “missed opportunity”. When Iryna presented the same data at the Educators’ Conference in 2008, it was interesting to contrast Michael Hurley’s account of the stress and frustration caused by his doctor’s repeated invitations to have an HIV test, the doctor perhaps motivated by a concern to avoid missing opportunities to surveill his HIV status.

DAVID WILSON does his thing about modelling.

Purposes of testing:

  • Surveillance systems to monitor trends in infection – we lead the world in surveillance because of high testing rates allowing us to monitor trends
  • For the infected individual, it enables them to begin treatment when needed and keep their CD4 cell count high. About 40% are diagnosed under 349 and 20% under 200 CD4.
  • For the uninfected but susceptible population – by informing the positive guys it enables them to change their behaviour and protect the negative guys.

On that third point, Wilson cites quite a number of studies that show behaviour change to reduce sexual risk-taking does occur after diagnosis (contra the Boston study).

Wilson presents data from Health In Men study showing that HIV-negative men practice strategic positioning based on their knowledge of their partners’ serostatus. As an HIV stigma nerd I’m interested to note that sexual rejection is not included in these graphs.
Wilson shows a graph mapping incidence and diagnoses. At 70% testing every year – our current rate – there’s maybe 50 diagnoses difference between incidence and diagnosis within 12 months. If you can increase testing by 10% you’d get a decreased incidence of about 20 cases per year. His models suggests 10-20% of the positive population is currently undiagnosed; above 20% undiagnosed, widespread uptake of serosorting would increase relative risk (above 1), at 10% it would be half that.

Wilson plays devil’s advocate by asking whether rapid testing might do more harm than good: with longer window periods (at 15 days, that’s 10 days longer than a 4th gen EIA test) we might miss some infections, and there may be false positives. If rapid testing took place at home, opportunities for counselling would be missed, and the quality of our surveillance might suffer from positive diagnoses not being notified.

If all of our testing switched to Orasure tomorrow, we’d miss about 5% of diagnoses or about 33 cases every year in Australia. But 95% would be caught — and those people would know they had become positive earlier than if they waited for a once-yearly in-clinic EIA test. Wilson estimates how much earlier on average they would know their status: about 11.4 days.

Wilson doesn’t consider the cultural and personal meanings of testing. One of the big roles testing can play is in confirming the safety of a person’s risk reduction decisions. One can get false confirmation if he doesn’t realise that HIV has rather low transmission efficiency, so that he interprets a negative test result to mean his risk reduction strategies work effectively, rather than simply meaning his number hasn’t come up yet.

Wilson doesn’t model the variable (or targeted) uptake of rapid testing – his models assumes 100% replacement of in-clinic EIA testing by rapid testing. In reality that’s not going to happen. Rapid testing is going to be picked up first by well-informed sexually adventurous men. Mike Kennedy asks this question but frames it as a problem of research methodology, suggesting Wilson made a mistake in ‘blinding’ the testing data, excluding information about recent sexual risk taking that might decrease inappropriate use of rapid testing.

MARTIN HOLT (NCHSR) presented on a literature review he conducted into the use of rapid testing overseas.

Common aims:

  • Increased uptake of HIV testing among at-risk populations eg gay men and MSM, homeless people, migrants from high prevalence countries, sex venue patrons
  • Increasing the proportion of those tested who actually get their test results
  • Reduce the number of diagnosed infections
  • Improve the consumer experience of HIV testing — thank god, finally someone gives some thought to the personal and cultural meaning of testing! Holt talks this in terms of the ‘aversive experience’ of testing and how rapid testing may reduce stress.

Martin discusses implementation issues learned from the use of rapid testing overseas, focusing in particular on adapting pre and post test counselling discussions. Concerns:

  • Risk of pressuring consumers to test or consumers consenting without fully understanding the implications — in public health this issue is minimised, resulting in an assumption that anyone who doesn’t want to test ‘is mad’
  • Rapid testing reduces opportunities for counselling and follow-up, eg. repeat testing as an opportunity for education over time
  • Confidentiality in rapid testing settings.

There’s another issue about how you tell someone the test has been reactive and yet requires confirmatory testing in a lab using the standard EIA test. Overseas this possibility is discussed in pre-test counselling and follow-up procedures become crucial; there’s a silence in the literature about whether consumers really understand the possibility of getting a reactive result.

In published evaluations, consumers have valued the speed with which results are delivered, the reduced anxiety of the shorter waiting period, and the less invasive collection method (eg saliva or finger prick). Of the small numbers who have tested positive, most have expressed satisfaction with pre and post test counselling.
Things a small number of consumers didn’t like:

  • Concerns that rapidity meant lower accuracy (which Martin describes as a deficit in their understanding, although I thought that’s exactly the trade-off involved)
  • Pressure to test and
  • “Misuse” of rapid testing by “high risk” individuals was identified as a concern by sex on premises venue operators in a feasibility study in the UK
  • Very high stress experienced by consumers with reactive results in waiting for confirmatory testing

Outcomes of rapid testing
  • Successful engagement of hard-to-reach and at-risk populations
  • Increases in numbers of people presenting for HIV testing in settings/populations with low uptake
  • Increased proportion of people receiving results
  • Some small number of undiagnosed infections identified

DR CHRIS BOURNE from “STIGMA” (STI in Gay Men Action Group)

Chris describes “point of care” testing (rapid testing in clinical settings) using a table too complex to represent here (or really understand without scrutinising it at length…)

He points out that sexual history-taking may be used to “triage” or judge the eligibility of a patient for rapid testing. He adds syphilis testing to the mix: if you also take blood for syphilis and the rapid test comes back invalid or reactive, you can just use the blood taken for the syphilis test to run the confirmatory EIA test. Chris notes the increasing use of telephone conversations and text messaging to deliver negative test results. He also points out that rapid testing in outreach settings will require experienced staff to help “contain someone who turns up positive” (clinician-speak for counselling/comforting).

YVES CALMETTE (ACON/NCHSR) presents on Rapid Testing in Community Settings

Yves begins with that beautiful picture of the MAGNET storefront in the Castro in San Francisco. The model is “sexual health services + community wellness services”. Since 2007 MAGNET has used a multiple-test rapid testing algorithm; for men at higher risk (based on sexual history-taking) the algorithm includes RNA testing to detect acute HIV infection within the tests’ window period. Yearly they test 7,200 people (out of about 60,000 gay/bi men in SF) and demand exceeds availability by about 30% each year. Yves summarises a whole range of reasons gay men have given in studies in other countries (I think?) for preferring rapid testing, and suggests a model for how rapid testing might be rolled out in Australia using a community outreach model.

MY TAKE

The value of outreach rapid testing depends on how much we are concerned about the 30% of men who don’t test as recommended every 12 months, or the 10% who have never tested. (The considerations are probably quite different depending on which group you focus on.) I still need to think about the issue, but I’m not sure there’s a huge problem for rapid testing to fix in the first place. Testing rates are already incredibly high.

Many of the men who don’t test every 12 months have rational reasons for not doing so — they may be religious about condom use or they may not practice anal sex at all — and that includes guys who have 10+ or 50+ partners every six months. There will certainly be a small number who have large amounts of risky sex with large numbers of people and never test, but we don’t have any reason to believe the reason they don’t test is that two weeks is just too long to wait or testing in a clinic is just too damn inconvenient for them.

Interestingly, Martin Holt during the panel questions notes that different sampling methods like those used in ASHR, Private Lives and e-Male, the ever tested rate falls to 70% (although the testing frequencies within the 70% remain about the same). He questions how rapid testing might change perspectives and expectations of testing and reduce some of the longstanding objections to testing among those never tested.

After this morning’s plenary, the session was a spectacular example of framing in action. Perhaps because they believe it will never get past the TGA, not one of the presenters considered the possibility of giving rapid tests to highly-risky gay men to use at their own discretion.

Yes, in that group there’s a possibility of acute infection being missed — which just means the window period and availability of PEP are key issues to cover in pre-test counselling, and the tests must be distributed through some channel where that can be guaranteed to occur.

Rapid tests could be prescribed by doctors from gay-friendly clinics and sexual health services to highly sexually active, sexually adventurous men based on history-taking. Those are the guys who have a high rate of partner change and high enough proportion of unprotected sex that detecting infection 11.4 days earlier might make a real reduction in onward transmission. You also reduce the likelihood of false positives freaking people out, and increase the likelihood that a person who tests positive has social support around him.

The other issue the discussion threw into stark relief was the desperate need to talk honestly to gay men about the window period of existing HIV testing. Where I have worked in the past, we quoted a 3 month window period, or 6 weeks if a caller was attending the local sexual health service (because we knew what tech they used). One possible factor in why people don’t test more often is because the ‘resolution’ of testing with a 3-month window period is so crude. A finer-grained resolution with an increment of 4 weeks would give more reassurance and better information about risk-taking (to the different groups of men for whom those factors respectively matter).

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