Awareness
of PEP is not everything, as one study from Sydney presented at the 2006 Toronto International
AIDS Conference found.1
Knowledge of PEP among HIV-negative gay men in Sydney had reached virtual saturation point,
with 97% aware of it. However near-universal knowledge had not translated into
universal use after HIV risk incidents. Just under a quarter of incidents of
the very highest-risk, namely unprotected receptive anal intercourse with an
HIV-positive partner, resulted in men seeking PEP.
The
study was from the HIM cohort, a group of 1427 HIV-negative gay men enrolled
via community venues in Sydney.
Researchers conducted two interviews a year about their sexual behaviour and
HIV risk factors. The yearly interviews have included asking cohort members if
they knew about PEP and had ever received it.
Baseline
knowledge of PEP was already high in 2001, with 79% of participants being aware
of it following earlier campaigns. By 2004 this had risen to 97% of
participants being aware of PEP, although this may be higher than the level of
knowledge in the gay community at large, as HIM cohort members are informed and
motivated enough to put themselves forward for research.
However,
the question must be, why did even more men not use PEP, considering this high
level of knowledge? When PEP was requested, it often followed unprotected anal
intercourse with a casual partner, but PEP following sex with regular partners
was less common.
In terms
of the type of anal sex, 8% sought PEP when they had been the active partner in
casual sex, 10% when they were the passive partner but their partner had not
ejaculated inside them, but 23% when a casual partner had ejaculated inside
them.
Use of
PEP was not associated with any change, either positive or negative, to
subsequent sexual risk behaviour with either regular or casual partners.
By the
end of 2005 there had been 42 seroconversions among the HIM cohort
participants, giving an overall HIV incidence of 1% a year. However, use of PEP
was not associated with reduced incidence: rather the opposite. Ten men who had,
at some point, sought PEP seroconverted, yielding an annual incidence among
this group of 3% a year.
This
does not mean that PEP, when taken, did not work, but that the men were also involved
in other HIV risk incidents where they did not seek PEP. HIV incidence was
higher in PEP users because risk behaviour was higher and PEP use for the
occasional incident did not compensate for this fact.
Some of
the reasons gay men may not use PEP after risk incidents were highlighted by another
study from Toronto2 in
which gay men were given ‘starter packs’ of PEP drugs. They had access to the
starter packs for six months and were told to call researchers via a 24-hour
helpline if they initiated PEP. They then got the remaining 25 days of PEP from
their clinic. The men used their starter packs after 26% of cases of
unprotected anal intercourse.
The
participants in this study were gay men who were not in a monogamous
relationship. The subjects were split between a youth group of 23 men aged 18
to 25 and an adult group aged 25 to 60.
Sexual
risk behaviour declined in both groups during the study from two-thirds of
participants reporting sexual risk behaviour at baseline to less than half at
nine months.
Nearly
all the adult group (89%) reported at least one episode of unprotected anal
intercourse (UAI) during the study but fewer of the youth group (73%).
Furthermore the men in the youth group were better at using PEP; nearly half
(47%) of incidents of UAI were accompanied by PEP use in the youth group
compared with only 29% of incidents in the adult group.
There
was a high rate of seroconversion in the study; five men (three from the youth
group and two adults) became infected during the nine months (an annual
incidence of 11%). Four of the five never used PEP and the fifth did not use it
during the three-month period he became infected.
So
why did the men
not take the pills in their bathroom cabinet after a risky episode? The poster
supplies a revealing list of reasons:
- “I just have a
feeling about which partner I can trust”
- “I’m not at risk
because my partner gets tested”
- “I’m lucky and
probably won’t get HIV”
- “I was in love with
him and didn’t want to think about it”
- “It wasn’t risky
because it was very brief”
- “Pulling out is
relatively safe”
- “As long as my
partner does not cum in me I can be certain I won’t get infected”
Since
only one of the people who seroconverted said they had changed their sexual
risk behaviour during the nine months, this study may document the limits of
what a purely biomedical prevention intervention can do for ‘high-risk’ gay men
without additional cognitive or behavioural help.
Three
years later, similar findings were reported from a study of gay men in Brighton, UK.3 It
suggested many were notaccessing
PEP when they needed it.
The
investigators conducted interviews with 15 gay men who were currently taking,
or had recently completed, a course of PEP after unprotected anal intercourse. They
wanted to gain a better understanding of the factors and rationale leading gay
men to access PEP and how these differed from occasions which warranted PEP,
but where they did not seek it.
The
men generally described the risky sex that led them to seeking PEP as “rare” or
a “one-off” and mentioned it within the context of drug or alcohol use. Such
risk behaviour was described as being out of character; the men generally
considered themselves as having a low risk of infection with HIV.
Another
common theme was linking such risk behaviour with sexual partners who were in
some way unusual or “other”. The men commonly attributed a number of risky
characteristics to partners with whom they had had unprotected sex, such as
sexually transmitted infections, promiscuity, “adventurous sex”, and a habit of
having unprotected sex.
Universally,
the men did not believe that they themselves had such risky characteristics.
Use
of certain venues was also associated with the subsequent accessing of
post-exposure prophylaxis, generally saunas, certain bars, and cruising grounds.
One individual told the investigators: “It was certainly kind of one-off I
think…it was in a sauna, where I’d gone after being out drinking”.
Most
of the men, however, were able to describe other circumstances when the use of
post-exposure prophylaxis would have been warranted but was not sought.
Generally, the sexual behaviour and partner was not perceived as being of
sufficient risk. One participant described his decision to access treatment on this
one occasion, but not others, in these terms: “What was different? To be honest
nothing - apart from they didn’t tell me they had HIV. So they might as well
have been positive and they just didn’t tell me.”
Unprotected
anal sex with other partners was widely reported. However, the men reported
that they “trusted” their partners or that it occurred within the context of a
relationship. Deciding to take a risk was rarely founded upon mutual HIV
testing. The investigators therefore conclude that gay men often fail to access
post-exposure prophylaxis because they do not perceive a sexual encounter to
have been high risk enough, despite the fact that it carried a high risk of HIV
exposure.
There
was no indication that use of post-exposure prophylaxis increased sexual risk
behaviour or that it was thought of as a replacement for other methods of HIV
prevention. Indeed, the idea that such treatment was a kind of “morning after
pill” was abhorrent.
However,
there was a willingness to attribute such beliefs to other gay men, which the
investigators believe is further evidence of a willingness to “other” sexual
risk behaviour.
In
their discussion of their findings, the investigators ask how many other MSM
are involved in similar exposure events and yet do not have the same triggers
for presenting to clinic. “Extra work needs to be targeted at understanding [PEP]
among men who have sex with men and improving the accuracy of subjective
calculations,” they said.