JOHANNESBURG, 10 December 2009 (PlusNews) - The percentage of
HIV-positive mothers who pass the virus to their newborn babies
in South Africa's KwaZulu-Natal Province has dropped by nearly
two-thirds since dual antiretroviral (ARV) therapy was introduced
for the prevention of mother-to-child transmission (PMTCT).
Before the national health department switched to dual therapy in
January 2008, pregnant women testing HIV positive were given a
single dose of the ARV drug, nevirapine, during labour, and their
babies received a dose when they were born. But a 2005 study
found that on the nevirapine-only regimen, one in five
HIV-positive mothers were still transmitting the virus to their
With dual therapy, HIV-positive women started receiving the ARV
drug, zidovudine (AZT), from 28 weeks of pregnancy, as well as a
single dose of nevirapine. Their babies received AZT for seven
days after birth, and a dose of nevirapine.
Some provinces have been slow to roll out the new dual regimen,
but a study conducted in six districts of KwaZulu-Natal between
2008 and 2009, revealed that the province rapidly implemented the
revised PMTCT guidelines, bringing down transmission to as low as
4.3 percent in one district, and 7 percent on average.
"The study started in May 2008, which was only eight weeks after
AZT was introduced, so it was actually quite a rapid rollout,"
said Dr Christiane Horwood, lead investigator of the study and
deputy head of the Centre for Rural Health at the University of
KwaZulu-Natal. "We spend a lot of time moaning about the [public]
health service, but I think this really shows an incredibly
During the study, 38,000 mothers from a mix of urban and rural
districts were interviewed; virtually all said they had been
tested for HIV, but more than two-thirds were only tested in
their final trimester, after the point when they should have
started taking AZT.
As South Africa's PMTCT guidelines stipulate that pregnant women
should be tested for HIV during their first visit to an antenatal
facility, Horwood surmised that many women started using
antenatal services very late in their pregnancies.
Of the 36 percent of women in the study who tested HIV-positive,
only 65 percent received results from CD4 count tests, a measure
of immune system strength essential for determining readiness to
start ARV therapy. The government recently announced that all
pregnant HIV-positive women with CD4 counts at or below 350 would
qualify for ARVs, but at the time of the study the CD4 threshold
for starting treatment was still 200.
South Africa's maternal mortality rate has remained stubbornly
high, partly because of the number of women with low CD4 counts
who die during childbirth; they are also more likely to transmit
HIV to their babies, a factor keeping the infant mortality rate
Two-thirds of women in the study who tested positive received
dual therapy, 14 percent received nevirapine only, and 13 percent
started ARV treatment. The researchers took blood samples from
8,013 babies aged between four weeks and eight weeks at
immunisation clinics, and found that of those whose mothers had
received dual therapy, 5.6 percent were HIV-positive compared to
13.5 percent of babies whose mothers only received nevirapine.
Horwood predicted that the new higher threshold for starting
HIV-positive pregnant women on ARVs could bring down
mother-to-child transmission rates to below 2 percent, but warned
that the new guidelines would place "a very major burden on the
"The proportion of women who are going to be in that under-350
CD4 count is a lot, and already getting people to clinics in time
is an issue, so it's going to be a big challenge," she told
IRIN/PlusNews. "Many steps in the [PMTCT] programme may become
Nevertheless, Horwood welcomed the effort to target this
vulnerable group and congratulated the government on expanding
its treatment programme. She also said there were plans to
replicate the KwaZulu-Natal study in the country's eight other
provinces, using the same methodology.