versión On-line ISSN 2078-5135
SAMJ, S. Afr. med. j. vol.101 no.8 Cape Town ago. 2011
Mothers and babies - widening the HIV safety net
A national health policy of exclusive breastfeeding is finally imminent while routine re-testing of initially HIV-negative pregnant women at 32 weeks could soon become standard practice.
These two simple measures would boost the already impressive gains in prevention of HIV transmission from mothers to infants (PMTCT) - a major highlight of the fifth South African AIDS conference in Durban from 7 to 10 June this year. National surveys presented at the conference showed that the MTCT rate among babies 4 - 6 weeks old has dropped to 3.5%, potentially saving some 67 000 infants from HIV infection. This is a dramatic acceleration from the 8.8% MTCT rate under the previous regime of a single dose of nevirapine to mothers and their newborns. The impressive gains are almost exclusively due to a much-awaited policy change last April when all HIV-positive pregnant women began receiving AZT from 14 weeks of pregnancy (instead of at 28 weeks) and triple therapy (nevirapine, tenofovir and 3TC) during labour (when most infections take place). Those women with CD4 cell counts below 350 were also put onto triple therapy within 2 weeks of getting their CD4 cell results and all HIV-positive newborns were given nevirapine syrup for as long as their mothers were breastfeeding them (or for 6 weeks if not breastfed), regardless of CD4 cell count. Together these measures have put South Africa on track to meet this part of its 2007 - 2011 National Strategic Plan on HIV/AIDS (i.e. reducing MTCT to less than 5%), with the latest policy changes likely to edge the country even closer towards European and United States MTCT rates, where paediatric HIV infections are 1% or less.
Between June and December last year, the national (Medical Research Councilled) PMCTC survey tested almost 10 000 six-week-old babies at 580 clinics in all nine provinces. Almost one-third of these babies had HIV-positive mothers, yet only 3.5% of the HIV-positive mothers had infected their babies. In KwaZulu-Natal, four out of ten newborns had HIV-positive mothers yet only 2.8% became infected. Gauteng's HIV transmission rate was the lowest in the country at 2.3%, while Mpumalanga (with arguably the most dismal provincial record of HIV/AIDS denialism) had the worst rate of 6.2%, almost twice the national average. The Free State had the second worst rate (5.7%). Dr Ameena Goga, the lead MTCT researcher at the MRC, reminded her audience that without any ARV intervention an estimated 30 - 40% of HIV-positive mothers usually transmit HIV to their babies during pregnancy, labour and after birth through breastfeeding.
New ART regimens make breastfeeding safest option
National Deputy Director General of Health, Dr Yogan Pillay, said South Africa was moving towards exclusive breastfeeding with Health Minister, Dr Aaron Motsoaledi, due to hold a high-level consultative meeting in August, 'after which we might stop giving formula feed out at clinics'. He admitted that government had given 'mixed signals about infant feeding' - which a prominent public health academic, Professor David Sanders of the University of the Western Cape, charged was not just a government malady. Sanders said infant feeding was too often ignored in AIDS discourses, including at conferences, and questioned whether the HIV community had really 'shifted in its views'. He pointed to research showing that most HIV-positive women practised mixed feeding (77% by 12 weeks postpartum) despite receiving free formula. This meant that many children were dying unnecessarily from infections, including diarrhoea and pneumonia. 'Now there is no excuse. With new ART regimens for pregnant and lactating women, breastfeeding is unequivocally the safest option,' he said. The MRC's Dr Tanya Doherty (one of the MTCT researchers) said she was worried that the national guidelines still recommend free formula milk through public health facilities despite World Health Organization (WHO) guidelines that the promotion of a single feeding method was likely to provide the greatest chance of child survival. In the South African context this single method was definitely breastfeeding. Without clear national guidance provinces tended to make their own policy decisions, sowing confusion at health facility level and in communities and threatening to reverse the significant PMTCT gains. Dr Goga warned that more babies were likely to test HIV-positive at 18 months, with mixed feeding proven as a significant cause.
Supporting the scrapping of free infant formula (which renders infants more vulnerable to unsafe water and already done away with in KwaZulu-Natal), Sanders emphasised that 65% of child deaths in South Africa were due to non-HIV conditions. He added that the country's under-5 mortality rate of 67/1 000 live births was currently worse than Bangladesh (54/1 000). Precious Robinson, deputy director of the State PMTCT programme, said that the battle to prevent all HIV-positive mothers from passing the virus on to their babies is finally 'winnable - we simply have to concentrate on the care of babies after birth'.
Retesting pregnant mums to catch virulent new infections
Explaining the new policy of women being retested at 32 weeks of pregnancy, she said 11% of pregnant women who tested HIV-negative initially became HIV-positive during pregnancy. This was alarming because it pointed to this cohort of people being responsible for transmitting the greatest portion of HIV to their babies (newly infected persons have very high viral loads). Robinson believes it is possible to eradicate mother-to-child HIV transmission by 2015 - if the latest measures become standard practice across all provinces.
Professor Salim Abdool Karim, Deputy Vice-Chancellor of the University of KwaZulu-Natal, told an international audience of scientists that on the 30th anniversary of the discovery of AIDS, the world had a much fuller toolkit to deal with HIV prevention than a year ago. He said five recent research results had the potential to transform HIV/AIDS prevention - if they could be translated into policy. In the latest trial of couples where one partner was HIV-positive and the other negative, if the HIV-positive partner was on ARV medication, their partner was protected from infection by a 'massive' 96%. Male circumcision offered 54% protection from HIV, while a study of gay men found that an ARV called Truvada taken before sex could prevent HIV by 44%. A trial in Tanzania found that if sexually transmitted infections were treated, this reduced HIV transmission by 42%. Finally, a year ago his Centre for the AIDS Programme of Research in South Africa (CAPRISA) found that a vaginal gel containing the ARV tenofovir could reduce HIV infection by 39%. The central challenge was to use these results to 'go forward ... to actually change the course of the epidemic at a community level,' he said. Abdool Karim, a co-director of CAPRISA, said his organisation was particularly concerned about the very high levels of HIV among young women and most of its research was geared towards this group.
South Africa now has 1.4 million people on ARVs, with 80% of all those with CD4 cell counts of 200 or below now on ARVs. The target is 2.3 million on ARVs by next year, including the latest ART expansion to all HIV-positive persons with a CD4 cell count of 350 or below (WHO guidelines). Government claims to have tested 12 million people since April last year but is doing less well with prevention efforts, currently well short of making its 2010 target of halving all HIV infections.