As breastmilk can transmit HIV, global policy was weighted in favour of bottle feeding and HIV positive mothers were discouraged from breastfeeding.

But a big study from KwaZulu-Natal led by Professors Jerry Coovadia and Nigel Rollins and published on Friday (30 March) seems to have finally settled the debate in favour of the breast.

They found that babies who were exclusively breastfed by their HIV positive mothers were at substantially less risk of becoming infected than babies given both breastmilk and formula milk or solids.

This is excellent news for HIV positive mothers living in poor areas without easy access to clean water and effective ways of sterilising bottles.

The formula milk position was all very well in the developed world and middle-class suburbia, where mothers with HIV who opt for bottle-feeding can get clean water to mix the formula.

But it was not geared for rural South Africa or urban informal settlements where the supply of clean water is not guaranteed and where it is simply impractical to boil water everytime to sterilise baby bottles.

However, up until now, government’€™s policy has favoured the bottle by offering mothers with HIV free formula milk. The proviso was that she had to have access to clean water ‘€“ but who was checking?

Besides, what poor mother would turn down free milk formula, even if she planned to breastfeed? In fact, researchers found that most mothers opting for the formula were unemployed and that at least a quarter of them admitted to selling it as they were desperate for income, so there was little benefit to their babies.

For Professors Coovadia, Rollins and colleagues at the Africa Centre for Health and Population Studies and the University of KwaZulu-Natal’€™s Medical School, offering free formula was a dangerous policy.

HIV positive mothers who opted for the free formula usually ended up both breastfeeding and bottle feeding.

But research published in 1999 by Dr Anna Coutsoudis, also from Durban, suggested that this ‘€œmixed feeding’€ was the most dangerous form of feeding for newborn babies with HIV positive mothers.   It damages the mucosal lining of the babies’€™ intestines, making them vulnerable to the virus.

There was also the added risk of bottlefed babies dying of gastro-intestinal infections caused by dirty water or unsterilised bottles.

In the past, long before the HIV epidemic, Coovadia had been actively involved in campaigns against Nestle and other big companies that were promoting formula milk in this country because babies in poor households were so vulnerable to gastric infections.

In addition, the physical benefits of breastmilk on building babies’€™ immune systems as well as the psychological benefit of breastfeeding in encouraging mother-baby bonding has been well established.

So even in the face of HIV, he and his colleagues were deeply uneasy about breastfeeding being undermined in favour of formula milk precisely because the risk of diarrhoea was high and often fatal for little babies.

They thus painstakingly investigated the risks that the different feeding options being used by over 1 000 HIV positive mothers in KwaZulu-Natal posed for passing HIV on to their babies from birth to six months.

The study was big, initially involving 2 722 HIV positive and negative women at seven rural and two urban sites.

All the women were counselled about the value of exclusive breastfeeding, and the majority opted to do just that. In addition, all HIV positive mothers were given nevirapine during labour and their babies at birth.

Their study, which was published in the prestigious Lancet journal, found that the risk of HIV transmission to babies exclusively breastfed by their HIV positive mothers up to the age of six months was 4%.

In contrast, babies who were given breastmilk and solids were almost 11 times more likely to get HIV, while babies who had both breast and formula milk had double the risk of HIV infection as those only on the breast.

In addition, deaths among babies who were formula fed were more than double that of exclusively breastfed babies by three months. Many of these deaths were not related to HIV but were the result of diarrhoea.

Six percent of the babies that were exclusively breastfed were dead by three months of age, while 15% of babies who were given replacement foods were dead.

The Lancet has hailed the study as a ‘€œbreakthrough’€, describing it as ‘€œmeticulous’€ and ‘€œproviding crucial confirmatory evidence’€ that exclusive breastfeeding poses a low risk of HIV infection for babies.

While a significant number of the babies died during the study, this relates to the fact that 14% of the babies were HIV positive already ‘€“ either infected while inside their mothers’€™ wombs or during birth, not through breastmilk. Three-quarters of the deaths were as a result of AIDS-related illnesses.

Babies were most likely to get HIV if their mothers had advanced HIV infection, associated with low CD4 counts (measure of immunity in the blood) and large amounts of the virus in their blood.