Welcome to the Australian Prescriber Podcast. An independent,
no-nonsense podcast for busy health professionals.
Hi, and welcome to this Australian Prescriber Podcast. And today
we’re going to be talking about HIV [human immunodeficiency virus] testing. I’m
Dr. Justin Coleman, a GP in Inala Indigenous Health in Brisbane. And with me, I
have a veritable expert on the matter of testing for HIV, and that is Louise
Owen. Louise Owen is clinical professor at the Statewide Sexual Health Service
at Tasmanian Health Service, and also the president of the Australian Chapter
of Sexual Health Medicine. Welcome to our humble podcast, Louise.
Thank you very much, Justin. Thank you for having me, and I look
forward to our chat.
Thank you. And I very much enjoyed reading your article in
Australian Prescriber, Testing for Human Immunodeficiency Virus. One thing was
just to keep up with the stats in Australia. So to quote from your article,
there’s about 30,000 people currently in Australia living with HIV as a recent
stat. And there were 757 new diagnoses in 2024. Although over the past decade,
there’s been a very welcome decline in overall new HIV diagnoses. It’s declined
by around about a quarter. And you mentioned in the article that, in
particular, that reduction is largely among gay, bisexual, and other men who
have sex with men. What do you put the decline down to, and does that alter
what we do in terms of testing?
Well, we know that testing is important, that people are aware of
their status, so that those people diagnosed with HIV can be linked to care.
And in Australia, we have a really good cascade of care where we think that
probably 92% of people living with HIV are actually aware of their status, and
97% of those are on treatment, and 98% of them have an undetectable viral load.
So we’re testing to detect cases so that we can get people into care and reduce
onward transmission. So the great news about the decline in HIV diagnoses each
year is related to our excellent responses in the prevention space
particularly, and that is the rollout of PrEP or pre-exposure HIV prophylaxis.
And that has been widely taken up in Australia with initial demonstration
projects and now on the PBS [Pharmaceutical Benefits Scheme] available for GPs
to prescribe, and also available for Medicare-ineligible patients either
through their GPs, through online providers, or sexual health services.
And there’s a wonderful new initiative rolling out at the moment
with some increased federal funding to particularly target Medicare-ineligible
people who may be at risk of HIV acquisition for them to access PrEP across
Australia. So those things have really helped the decline in HIV diagnoses and
also people on active treatment with antiretroviral therapy who have an
undetectable viral load have no risk of transmitting the virus sexually. And so
we have treatment as prevention as well.
Undetectable equals untransmissible. I think that’s a wonderful
phrase you also mentioned in the article. So we’re not going to look at the
treatment any further during this particular podcast. So we’re really looking
at those 8% of people you mentioned living with HIV in Australia who are
unaware of their HIV status and ways in which we can cut that number down and
detect that. But without the universal testing, which is applied in some other
countries based upon a higher prevalence of HIV. So we’re going to talk about
where to concentrate our testing with a view that if you get this early, it
really does make a difference because the early initiation of the therapy gives
almost no drop in life expectancy compared to those without HIV.
Yes, that’s right, Justin. But unfortunately, a number of the
diagnoses in the last statistics of 757 new ones, a considerable number of
those were late diagnoses. So that means the person is likely to had HIV for
some time, have a decreased CD4 count, the immune cell count, and often have
had a number of medical conditions relating to that whilst not perhaps AIDS-defining
illnesses. And so yes, there’s a significant health impact and public health
impact and health cost to that undiagnosed HIV case. So our testing push is
towards elimination of HIV transmission, and if people are aware of their
status, we can impact on that. And the current HIV task force led by the
Minister for Health is looking at that and all the different ways that we can
impact on that.
Okay. So looking at that 8% of people who potentially we need to
be finding out whether they have HIV, let’s look at what populations we should
be testing, given it’s not universal. The first one in Australia is antenatal
screening. That’s universal during the antenatal period, and that’s
standardised cross Australia. All guidelines recommend that. The second big
category is during STI [sexually transmissible infection] screening. Can you
just talk to me about that?
If I can just add, Justin, of course, we’re adding the syphilis
test for the antenatal population and at least 3 tests for all pregnancies and
sometimes more in areas of high syphilis prevalence. Just can’t go past saying
something about that. Thank you. So in terms of STI screening or testing, HIV
and syphilis testing are part of routine screening for all epidemiological risk
groups. So if we can normalise that testing and majority of these tests will be
negative, we are putting in place the normalisation of testing and making it
easy for the clinician and the patients to seek that. Within that group, of
course, depending on the sexual risk and practices of the patient, it
determines what other tests we might be doing. And there’s really fantastic
guidelines for everyone out there on the Australian stiguidelines.org.au, which
can break it down by population group. So you may be seeing a person who’s assigned
male at birth who has sex with other men, and it will talk about which sites
that should be tested along with the HIV, syphilis, and hepatitis B screening
tests.
And then of course, there may be other risks such as people who
may inject drugs or people who have been incarcerated, people who’ve travelled
to high-prevalence countries or had risk behaviours with people from high-prevalence
risk countries. So we can pop STI discussions into our pre-travel conversations
with our patients and certainly on their return from travel to consider HIV and
syphilis testing as part of that.
There’s a particular subgroup where testing is recommended
approximately every 3 months, which is distinct from some of the STI
testing, which we’ll be doing in general practice opportunistically or when
there are symptoms.
Yes. So certainly there are guidelines around people’s sexual
practices, particularly those patients on PrEP. The current guidelines do
recommend STI testing every 3 months, and that’s in line with the PrEP
prescription most often for people who are on daily PrEP.
And a brief mention of healthcare workers. In my job, I do a lot
of skin excisions and joint injections and things like that, but I don’t
believe that puts me at particularly high risk. It’s really for where you’re
handling sharps in body cavities, which are not necessarily in your view at all
times.
That’s right. And so practitioners who are conducting such
examinations or procedures do need to be aware of their status, Justin. And if
they are diagnosed with a bloodborne virus, then they are required to be linked
to a specialist care. And in the case of HIV, have undetectable viral load and
linkage with a specialist.
Just to clarify, the procedures you’re talking about are, for
example, open abdominal or thoracic procedures, not office procedures.
That’s correct, yes. And there is an excellent guideline [CDNA National
Guidelines for healthcare workers on managing bloodborne viruses] that we
can put the link in with the Australian guidelines for practitioners.
Wonderful. Thank you. Now, Louise Owen, I would like to move on
now to these HIV indicator conditions. Some of these things, of course, happily
we see very rarely these days such as Kaposi sarcoma, which when I was a
medical student was sadly becoming common throughout the ’90s, but some of them
we might not think of as potential HIV indicator conditions because they’re
often caused by other things, but we should be testing those. So there are 3
categories of these conditions. Could you run us through those?
So we’re thinking about the well-known AIDS-defining illnesses as
the first category. So if a patient presents with pneumonia and it’s thought to
be pneumocystis pneumonia, then majority of clinicians, hospitals, ICUs
[intensive care units], EDs [emergency departments] would be running a HIV test
for that patient. Other less well-known AIDS-defining illness include cervical
cancer, Kaposi sarcoma, Hodgkin lymphoma, and also oesophageal candidiasis. But
we could be possibly sure that some people in those categories are not getting
a HIV test, and some may well have a reason why they have oesophageal
candidiasis. But the question is, should we rule out HIV?
And then there’s a group which perhaps your average GP might come
across a bit more often because they’re not very specific for being caused by
HIV, but they can be caused by it. And I think the calculation is that if the
HIV prevalence is more than 0.1% or higher, then that’s when we test. What are
those conditions?
These are conditions that do come across the daily desk of our
colleagues in general practice, such as unexplained weight loss, unexplained
diarrhoea, thrombocytopenia, multidermatomal shingles, or recurrent bacterial
pneumonia. Any STI should prompt HIV and syphilis testing, of course, as should
the diagnosis of hepatitis B or C. So many of these situations on their
own may not be much of an alert, but particularly we could look at our patients
and say, ‘Hmm, there may have been one or 2 of these conditions in the
last 12 months. We need to rule out HIV.’ And in these situations, it’s
ideal that the clinician could ask a sexual history, but perhaps that will not
be very helpful because perhaps this is a person who doesn’t have any
identifiable risk factors, but perhaps may be at risk from their partner or
past activities. And so the clinician then says, ‘You have this condition,
insert thrombocytopenia or other clinical indicator condition. I suggest we
need to do a number of tests and we should rule out HIV.’
A lot of this is now on the HealthPathways, Justin, which can help
GPs look when they’re doing a thrombocytopenia screen. HIV is up there ahead of
doing a bone marrow biopsy, for example. And at $15 a test, yes, it is deemed
to be cost effective if the prevalence is thought to be 0.1% or more. Now, we
do get asked, ‘Well, how do we know what the prevalence is in our population?’
And these are based mainly on European studies, but in our quest to get to
zero, we do feel that it’s cost effective to order the $15 test. In these
situations, often we have ruled it out and the patient doesn’t need multiple
HIV tests, unlike the scenario where someone has an ongoing or intermittent
sexual risk or other practices that puts them at risk.
And the third and final category is where you really can’t afford
to be missing HIV.
Yes. And this is often done as part of a standard workup for
people who are receiving systemic chemotherapy or immune-modulating therapies.
So we’re just raising awareness, is that happening or are people putting a
judgement on whether or not someone might be at risk of HIV and doing a test
only in that scenario? So the aim is that if you’re about to start systemic
chemotherapy as part of the ruling out prior to that treatment, then HIV
testing workup would be recommended.
Let’s move on to the tests themselves. As most would be aware,
there is a window period for a test, which isn’t perhaps so relevant for
someone at continuous risk or in one of those categories we mentioned, but
certainly might be relevant for someone who’s had a recent episode where they
may have come into contact with HIV, for example, a recent other sexually
transmitted infection, and there you can get that false negative early on if
you test too early.
Yes. So the GP or other clinician is really just asking for HIV
serology test and send that off. The lab then does one of the fourth-or fifth-generation
tests, which is looking for antibody and antigen that are produced and detected
in the test. So very early infection, known as the window period as you
mentioned, may not be detected. And so it is good to have a history in terms of
the explicit risk that the person may have had and then recommending retesting
within 6 to 12 weeks after that risk. So it can be reassuring about
every other, for example, sexual risk they may have had prior to this most
recent one, but we’ve still in the window period.
So Louise, until I read your article, I was unaware there was such
a thing as a point-of-care rapid HIV test. Where are they recommended? Who
should be using them?
Well, the rapid point-of-care testing are usually used by
healthcare workers and often in remote, regional areas. For example, our
hepatitis C nurses who are outreach can take hepatitis C and HIV
point-of-care tests with them. So the most common setting would be in outreach
or rural and remote settings. And again, this is a really great extra tool that
we have to exclude HIV quickly, understanding the window period that may be
slightly longer than the laboratory tests, but any reactive point-of-care test
would be followed with a serological test for confirmation.
So like most point-of-care tests, they’re a very useful screening
tool where you may otherwise not get the person to have the formal test, but of
course any equivocal result or positive result you’d want to back up with a
formal lab test as they’re not going to be quite as good.
That’s right. It’s great. And there’s also the rapid self-testing,
which is available for people to apply online to get a free test delivered to
the address of their choice. They are available on vending machines and other
community providers. And this is another opportunity for people to self-select
and have a test that they can do at home. If that test is reactive, of course
it’s recommended they reach out to a clinical service to have further testing
and care.
We’ll end now on what to do with a negative result and a positive
result. We’ve sort of covered the negative one in the sense that we take it in
clinical context. Is it in the window period? Are they at ongoing risk and will
need further tests? But the HIV serology is really very accurate. It’s a
sensitive and specific test more so than most other tests we order actually in
general practice. I’m particularly interested what we do and what the lab does
with a positive result.
Well, the initial screening test or the ELISA [enzyme-linked
immunosorbent assay] test looking for the antibodies and antigen test, if that
is reactive, then that is followed on by a more sensitive and specific test,
which may be the Western blot, or in some cases, an RNA test to detect the HIV
virus. And again, as you mentioned, a positive test in this regard is highly
sensitive and specific and conclusive of HIV infection.
And in that case, the laboratory certainly automatically notifies
public health, but also in the majority of cases would be contacting the
clinician who ordered the test. And I guess thinking about the statistics of
0.1% and the clinical indicator condition prevalence, GPs are likely to order a
lot of tests and not have a positive, but we want to reassure you that if you
were to have a positive result, there will be assistance available very quickly
from your local sexual health service, ID [infectious diseases] service, or
other experts to assist the clinician who’s made the diagnosis with linking the
patient to care and getting them onto treatment really quickly. And Australia
again is doing really well with that and antiretroviral medication is free to
people without Medicare as well. And it’s available, of course, for people with
Medicare, but there may be a dispensing fee. Just a clarification there.
Wonderful. Clinical Professor Louise Owen, thanks for joining us.
There’s lots of information in that article if anyone wants to follow up on
anything we’ve discussed, in particular, the 3 categories of the HIV indicator
conditions. Thanks for coming along today and helping clarify it all.
Thanks, Justin. It’s been great to chat to you today.
[Music]
The views of the hosts and the guests on this podcast are their
own and may not represent Australian Prescriber or Therapeutic Guidelines.
Louise Owen is the President of the Australasian Chapter of Sexual
Health Medicine and previous co-Vice President of the ASHM Board. Louise
contributed to the development of the ASHM Post-Exposure Prophylaxis for HIV
Guidelines, for which she received an honorarium, as well as the development of
ASHM’s HIV s100 Prescriber Course. Louise is on several ASHM national steering
committees and state advisory committees for LGBTQIA+, HIV and hepatitis
working groups.