A
four-country African study of mothers with HIV giving birth in 2007 and
2008
has shown that up to half of children exposed to HIV during pregnancy
and
childbirth did not receive nevirapine to prevent HIV infection at
the time of delivery.
Younger
mothers and those who made fewer visits to the health facility before
giving
birth were significantly less likely to have taken a dose of nevirapine,
and
their infants were less likely to have received a dose of nevirapine
after
birth, according to results of a study published on 18 July in the Journal
of
the American Medical Association to coincide with the opening day
of the Eighteenth International AIDS Conference in Vienna.
Calls for a
greater effort to employ proven interventions in the prevention of
mother-to-child transmission are prominent at this year’s International
AIDS Conference.
“The
virtual elimination of mother-to-child transmission by 2015 is
sacrosanct,”
said Michel Sidibé, Executive Director of UNAIDS, in his plenary address
to the
conference.
Speaking at
the Children First conference preceding the AIDS conference, UNICEF’s
HIV &
AIDS chief said: “In 2010 the stars are aligned for the elimination of
vertical transmission. We can see the pathway to make this happen by
2015. The
question is, how do we get systems to work together, how do we get
programmes
to talk to each other?”
Experts
believe that vertical transmission – transmission of HIV from mother to
child
during pregnancy, delivery or breastfeeding – could be virtually
eliminated by
2015 if national programmes are able to implement a number of key
measures:
Adopting new
WHO guidelines for prevention of mother-to-child transmission to ensure
that
the most effective regimens are being used, and moving towards earlier
antiretroviral treatment for all women who are medically eligible.
Promoting
integration
of HIV services, maternal-child health services and family planning in
order
to reduce the number of unintended pregnancies.
Prevention
of
HIV infection of women.
Comprehensive
care for families, particularly through integration of HIV into
maternal-child
health services.
However the
research presented today, carried out by Jeffrey and Elizabeth Stringer
of the
Centre for Infectious Disease Research in Zambia
and colleagues in Cameroon, Ivory Coast and South Africa, shows that
there is
still a long way to go to achieve high levels of coverage of the key
interventions.
The
researchers tested umbilical cord blood samples at delivery in 27,893
randomly-selected mother-infant pairs, of which 12% were HIV-positive.
Out of
3196 deliveries by HIV-positive mothers, mothers took nevirapine in 1845
cases,
and both mothers and infants were dosed with nevirapine in 1725 cases.
The
virtual elimination of mother-to-child transmission by 2015 is
sacrosanct, Michel Sidibé, Executive Director of UNAIDS
The average
coverage was 51%, and there were large variations between countries and
within
countries, but multivariable analysis found that location was not
significantly
associated with failed coverage of nevirapine.
Women under
30 were less likely to be covered by nevirapine prophylaxis, as were
those who
attended fewer than six antenatal clinic visits during pregnancy.
The authors
say that these findings have immediate implications for counselling of
young
mothers, and underline the importance of repeat antenatal visits.
However
they say that the underlying problem is a series of failures in the
cascade of
actions that are necessary for a mother to take a dose of nevirapine –
or other
antiretrovirals – to prevent vertical transmission.
This cascade
of actions – all of them critical – consists of:
Documentation that the mother
has presented to the health facility, and the opening of a health
record
which documents all of the subsequent critical steps in this
pathway;
Offer of maternal HIV testing;
Acceptance
of testing;
Giving the HIV test result to
the mother and recording by the health facility;
Dispensing
of maternal
nevirapine or other antiretroviral regimen;
Taking
nevirapine (or other
antiretroviral drugs) as instructed;
Infant given
nevirapine prior
to discharge from hospital or within 72 hours of birth at home. The
infant
dose is necessary to maximise the protective effect of nevirapine
prophylaxis.
A failure
at any point in this pathway after documentation means that prophylaxis
cannot
prevent infant HIV infection.
The
international comparison found large variations in performance at each
stage of the cascade, suggesting that one of
the most critical issues in ensuring virtual elimination of vertical
transmission
will be quality improvements in care at each stage at every
health facility.
“Even the
most potent interventions will not protect those infants who do not
receive
them,” the research group conclude.
But the
inherent complexity of this pathway, with so many steps in comparison
with
initiating antiretroviral therapy for the mother, may be another strong
argument for promotion the widest possible adoption of new WHO
guidelines
recommending treatment for mothers with CD4 counts below 350 cells/mm3.
A recently-published
modelling
exercise using data from a Zambian cohort estimated that 80 to 90%
of
vertical transmissions could be prevented if women with CD4 counts below
350
cells/mm3 received three-drug antiretroviral therapy.