The Swedish national quality registry InfCare
HIV includes more than 99% of all known HIV
cases in Sweden. According to the registry, 87% of
all HIV-positive patients in Sweden were receiving
ART in 2012 (http://infcare.com/hiv/sv/resultat/2012-
arsrapport/, in Swedish). Of these, 92% had effective
ART, i.e. a plasma viral load <50 HIV RNA copies/ml. (This is among of the highest percentages of any country). In light of this and the findings of the HPTN 052 study, there is great demand for comprehensive
information about the most current evidence on the
risk of transmission from patients who are on effective ART.

Assessment of the risk of transmission
through sexual contact

The risks of transmission through vaginal and anal
intercourse in cases of effective ART are as follows:
There is minimal risk of transmission through

vaginal and anal intercourse if the HIV-infected
partner is on effective ART and a condom is
used throughout intercourse.
There is also a very low risk of transmission

through vaginal and anal intercourse if the
HIV-infected partner is on effective ART and
a condom is not used.
The above applies for each individual sexual

contact and in cases of repeated contact over
the course of longer periods (y), regardless of
whether the HIV-infected partner is a woman
or a man and regardless of whether the HIV-
infected partner is penetrative or receptive during the sexual act.
With regard to the risk of transmission through vaginal intercourse, the assessment above is supported primarily by the prospective HPTN 052 study [2], but also by several observational studies. A recently published meta-analysis of the results from 6 different studies covering a total of 6070 heterosexual serodiscordant couples where the HIV-positive partner had effective ART calculated the risk of transmission to be 0.01 per 100 person-y [11]In the treatment group of the HPTN 052 study
there was 1 transmission observed in approximately
1500 person-y, which corresponds to a risk of trans-
mission of approximately 1 per 150,000 sexual con-
tacts. Furthermore, it has been reported that this
single observed transmission took place before or
very soon after the HIV-infected partner had initiated ART. This means that the available data do not
contradict the Swiss statement that there may be a
non-existent (zero) risk of transmission through vaginal intercourse when a patient is on effective ART.
However, zero risk is impossible to demonstrate scientifically. It is probable that the risk of transmission is also minimal in cases of effective ART even when a condom is not used. However, because condom use was encouraged in the HPTN 052 study, there is insufficient scientific evidence currently available to support such a conclusion. In addition, condoms are recommended because the risk of transmission of other sexually transmitted infections may be present in the absence of symptoms. There is a lack of knowledge about the potential of other barrier methods to
reduce the risk of transmission.
Furthermore, the risk of transmission is assessed
to be very low even if treatment does not entirely
comply with the above criteria of effective ART. This
is based on the reduction in the risk of transmission
of at least 96% seen in the HPTN 052 study, even
though effective ART was defined as a viral load
<1000 copies/ml, rather than <50 copies/ml.

http://informahealthcare.com/doi/pdf/10.3109/00365548.2014.926565