Improving the Management of HIV Disease Vol. 6, no. 5 [World Conference on AIDS (12th: 1998: Geneva)]

International AIDS Society-USA

I 39.Is the delivery of postsexual exposure prophylaxis achievable and costeffective?
DR FISCHL: The efficacy ofpostsexual
exposure prophylaxis has yet to be determined and will be influenced by the relative risk of acquiring HIV infection in
this setting.
When the risk is relatively low, the
demonstration of benefit may be difficult. In addition, the role of postsexual
exposure prophylaxis is more difficult to
define with repeated sexual exposures to
HIV. However, there are enough data
related to the prevention of perinatal
transmission of HIV and health care
worker exposure to assume that in the
case of a maximal-risk sexual exposure,
prophylaxis with combination antiretroviral therapy should decrease the relative
risk of infection with HIV.
DR VOLBERDING: There is no reason to
think that prompt antiretroviral therapy
following sexual exposure to HIV will not
reduce the risk of infection. The problem
is that so many other issues need to be
considered in such situations. Often, data
on the actual risk (is the partner known
to be HIV infected, for example) are not
available. And the risk may be a recurring one.
Ideally, such treatment should be
offered in a setting where data are being
collected and where the primary purpose
is one of exposure prevention, not
postevent prophylaxis.

40. Would you recommend
postexposure prophylaxis
fora person who has just
had sexual contact with
someone in whom HIV
infection is highly suspected but not confirmed?
DR CONWAY: In this context, a person
at high risk of HIV infection but who has
not yet been diagnosed as such should be
considered to be infected until proven
otherwise. Thus, postexposure prophylaxis to protect against the potential
transmission of HIV should be offered to
the person who is being evaluated. This
is particularly true if the presumed
"index" case is male, if a condom was not
used, or if genital lesions (particularly
ulcerative lesions) were present on either
partner. A particular situation may relate
to the index case having been recently
infected. In such a case, the viral load in
genital secretions may be quite high, further increasing the risk of transmission
of HIV. This being said, the postexposure
prophylaxis to be used may be kept quite
simple, as the individual transmitting
HIV infection is presumably drug-naive
and is unlikely to be carrying drug-resistant strains. To date, the only drug to
which a significant prevalence of primary
drug resistance is reported is zidovudine,
and it may be best to avoid the use of this
agent in this context. If therapy is initiated, it could be discontinued if the index
case has a negative antibody test for HIV
infection and acute or early HIV infection can be reasonably ruled out on clinical or laboratory grounds.
DR D'AQuILA: This is a difficult question to answer in the abstract, and it does
not become any easier when facing an

actual patient. My inclination is to say
that the appreciable risk of adverse
effects with antiretroviral regimens precludes prophylactic treatment unless the
sexual contact is confirmed to be HIVinfected. However, the only alternative
approach I could offer to such a potentially exposed patient (who would certainly be quite anxious) is to closely follow repeated plasma HIV RNA levels
over the next few months and treat primary infection aggressively if it is detected. But I suspect many patients would
not be satisfied with that approach. Thus
if I were confronted with a compelling
situation about a high-risk sexual exposure to HIV from a person who was suspected, but not proven, to be infected, I
might indeed respond to a request for
prophylaxis with information about
adverse effects and a prescription for a
potent combination.
41. Do you believe that in i99gg8,
less than maximally suppressive postexposure prophylaxis should be recommended? Centers for Disease
Control and Prevention has
dual nRTI as options, but
many other guidelines (UK,
IAS-USA) do not.
DR HIRSCH: Determination of the actual
exposure risk in an individual situation is
very difficult. In my view, once the decision has been made that a risk for significant exposure exists, maximally suppressive regimens should be employed. These
might involve 2 nRTIs plus 1 protease
inhibitor, or 2 nRTIs plus 1 NNRTI.
Although these choices will be more costly and potentially toxic than less aggressive regimens, they should provide the

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