Featured news from NHIVNA
HIV-related news from NAM
Small risk of sexual transmission of HIV persists through first six months of ART
Michael Carter, 2016-05-10 10:30:00
A risk of HIV transmission
to sexual partners persists for six months after the initiation of
antiretroviral therapy, investigators from a large prospective prevention study confirm in the online edition of the Journal
of Acquired Immune Deficiency Syndromes. Over 1,500 serodiscordant
heterosexual couples were included in the analysis. Initiation of
antiretroviral therapy (ART) was accompanied by a fall in the risk of
transmission, but the risk persisted during the first six months of treatment.
No transmissions were observed once patients had been taking treatment for over
is markedly reduced once effective ART has resulted in complete virologic
suppression in blood and genital secretions,” comment the authors. “However,
this prospective follow up of 1592 HIV serodiscordant couples after ART
initiation by the infected partner demonstrates residual risk of transmission
during the first six months of ART. They believe “the first six months after
ART initiation may be a period of transition and persistent risk, with
declining markers of transmission but not yet minimized risk.”
ART suppresses HIV
replication in both blood and genital secretions. This reduces the risk of
transmission to sexual partners. Large prospective studies have evaluated the
impact of ART on infectiousness. No infections have been documented when a
patient has been taking virologically suppressive ART for over six months, but
there is some evidence that a risk of transmission persists in the initials months
of treatment, probably because full viral suppression has not yet been achieved
in the genital tract.
The Partners PrEP study recruited HIV-positive people not yet eligible for treatment and their uninfected partners, and randomised the uninfected partner to receive either
tenofovir, tenofovir plus emtricitabine (Truvada) or a placebo. Investigators from
the Partners PrEP study wanted to establish a clearer understanding of
the risk of transmission during the early months of HIV therapy and its
relationship with blood and genital tract viral suppression and sexual risk
behaviour. They examined the speed of virological suppression in HIV-positive participants who did not qualify for treatment under national guidelines on entry to the study, but who subsequently became eligible for treatment during the study.
examined data obtained from approximately 1600 heterosexual couples in Kenya
and Uganda where the HIV-infected partner started ART during the study. These patients provided
paired blood and genital secretion samples that allowed the investigators to
measure the decline in viral load in these compartments after ART initiation.
Their uninfected partners were regularly tested for HIV and the couples provided
information on their use of condoms. Data were also gathered on the incidence
patients were followed for a total of 474 person years until first viral
suppression (below 80 copies/ml) in blood. The median time until the first viral load measurement was a little over three months. Cumulative probabilities of
achieving blood viral suppression at three, six, nine and twelve months after
treatment initiation were 65%, 85%, 89% and 91%, respectively.
HIV was detected
in 12% of cervical and 21% of seminal samples collected in the first six months
after initiation of treatment. Median viral load in cervical and seminal
samples with detectable virus was 3.18 log10 and 2.60 log10,
There was evidence
that couples were having unprotected sex during this initial six month period.
Incidence of pregnancy was 8.8 per 100 person years and sex without condoms was
reported at 10.5% of study visits.
reduced the risk of HIV transmission.
among the uninfected partners was 2.08 per 100 person years in the period
before their partner started HIV therapy. This fell to 1.78 per 100 person
years in the first six months of treatment (three infections during 168
person-years of follow-up). Incidence fell to zero after six months of ART (no
infections during 167 person-years).
“Among African HIV
sero-discordant couples, we observed residual risk of HIV transmission,
measured through virologic and behavioural outcomes, during the first six
months of ART,” the investigators conclude. “Other prevention options such as
PrEP are needed for HIV sero-discordant couples in which the infected partner
delays, declines or is starting treatment. Ongoing studies are designed to
provide further evidence of ART effectiveness for HIV prevention.”