New Mother-to-child HIV Transmission Study in Africa
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Early Data from Mother-to-child HIV Transmission Study in Africa finds
Shortest Effective Regimen Ever
UNAIDS Research Points to Important New Strategy for AIDS Prevention in
Developing Countries
Preliminary findings from the largest clinical trial ever to examine
mother-to-child transmission of HIV open the way for a new, simpler
strategy for reducing HIV infection among babies in the developing
world.
According to the Joint United Nations Programme on HIV/AIDS (UNAIDS),
when an HIV-positive mother begins an antiretroviral regimen at the
time of delivery, and she and her new-born follow a postpartum regimen
for just one week, the chances of the infant becoming infected are re-
duced significantly (by 37 percent). Prior to this breakthrough, the
shortest regimen proven to be effective began during the mother's 36th
week of pregnancy three to four weeks before delivery.
"Over half a million babies are infected with HIV every year, most of
them in sub-Saharan Africa where access to health care can be limited,"
said Dr Peter Piot, Executive Director of UNAIDS. "Now we may be able
to help women protect their babies, even if they do not come to a hos-
pital or clinic until very late in pregnancy."
The research, presented today (1 February) at the Sixth Conference on
Retroviruses in Chicago, analysed rates of mother-to-child (also called
perinatal, or vertical) transmission among 1357 out of 1792 partici-
pants in the UNAIDS PETRA (PErinatalTRAnsmission) trial. The trial,
conducted in five urban settings inSouth Africa, Uganda and Tanzania,
evaluated three regimens using zidovudine (ZDV, or AZT) and lamivudine
(3TC), as compared with placebo.
Transmission rates in all trial arms were measured at six weeks after
birth. The researchers are still analysing data from the long-term fol-
low-up of infants because HIV can be transmitted through breast milk
and the majority of women in the trial practised breastfeeding. How-
ever, early reports from other studies among breastfeeding populations
indicate that the preventive effects persist for at least 6 months. The
babies and mothers in PETRA will be followed for 18 months. Other early
PETRA results indicate that the inclusion of a one-week postpartum
course of antiretrovirals for mother and baby is crucial. Among women
who received only an intrapartum regimen, with ZDV and 3TC taken during
labour and delivery, transmission was not at all reduced. In the long-
est regimen, women started ZDV and 3TC in the 36th week of pregnancy,
followed by the intra- + postpartum regimen. Among these women, there
was a 50 percent reduction in transmission. Similar findings had
emerged earlier from a study among non-breastfeeding Thai women by the
Centers for Disease Control and Prevention (CDC) and the Thai Ministry
of Public Health (MOPH) in which ZDV alone was given from the 36th week
of pregnancy through delivery.
"It is vital to develop a range of prevention options for mother-to-
child transmission so that countries can cater for women living in dif-
ferent real-life situations", said Dr Awa Coll-Seck, Director of Pol-
icy, Strategy and Research for UNAIDS. "We hope that as more data are
gathered, more public health officials and donors will see the value of
investing in mother-to-child transmission programmes in the countries
hardest-hit by the AIDS epidemic".
In the absence of preventive strategies, mother-to-child transmission
rates range from 25 to 35 percent among breastfeeding women. According
to estimates, nearly 600,000 babies are infected a year in total. One-
third of them acquire HIV through breastfeeding, a risk that is elimi-
nated if the mother uses a replacement method for infant feeding. But
for many HIV-positive mothers in developing countries, the risk of
their infant dying if not breastfed could be even greater than the risk
of transmitting HIV infection through breastmilk.
Furthermore, in places where women may be ostracised and even endan-
gered should their HIV-positive status become known, women may choose
not to use replacement feeding for fear of being identified as HIV-
positive. Hence the need to find prevention methods that are effective
for breastfed infants. "As final results come in from this and other
mother-to-child transmission studies, public health officials will have
more choices available, especially as more information about the dynam-
ics of transmission through breastfeeding emerges", said Dr Joseph
Saba, a clinical research specialist at UNAIDS who manages the PETRA
trial.
Glaxo Wellcome announced last year that it would substantially lower
the pricing of AZT for the prevention of mother-to-child transmission
based on the CDC Thai trial regimen. In view of the early PETRA re-
sults, Glaxo Wellcome has pledged similar public sector preferential
pricing for 3TC and Combivir (the fixed-dose combination of AZT and
3TC) in an effort to support this regimen as another option in estab-
lishing effective mother-to-child public health programmes in develop-
ing countries.
The PETRA study is part of an international research effort coordinated
by the UNAIDS Informal Working Group on Prevention of Mother-to-Child
Transmission of HIV, with membership of all research institutions in-
volved in mother-to-child transmission trials including the CDC, the
National Institutes of Health (NIH), and the French Agence Nationale de
Recherche sur le Sida (ANRS). The working group has sought to identify
the most promising drug regimens for testing and to co-ordinate trial
designs to eliminate duplication of effort and compare results.
The following institutions conducted the PETRA trials: In South Africa,
the Baragwanath Hospital, University of Witwatersrand, Johannesburg,
and King Edward Hospital, University of Natal, Durban; in Tanzania, Mu-
himbili University and General Hospital, Dar-es-Salaam; and in Uganda,
Mulago Hospital, Makerere University, Kampala, and Nsambya Hospital,
Kampala. Data management and analysis was conducted by the National
AIDS Therapy Evaluation Centre in Amsterdam. The PETRA study has re-
ceived financial support from Australian AID (Australia), Istituto Su-
periore di Sanita (Italy), Het AIDS Fonds (Netherlands) and the Swedish
Agency for Research Co-operation with Developing Countries(Sweden).
For more information, please contact:
Anne Winter
UNAIDS, Geneva
Tel: +41-22-791-4577
Lisa Jacobs
UNAIDS, Geneva
Tel: +41-22-791-3387 or
Karen O'Malley
at the Retroviruses Conference in Chicago
Tel: +1-312-329-7281
You may also visit the UNAIDS Home Page on the Internet for more infor-
mation about the programme:
http://www.unaids.org
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