[LOS ANGELES] The benefits of breastfeeding outweigh the risks of virus transmission from HIV-positive mothers to their children, according to studies conducted in four African nations.

The studies were presented at the Conference on Retroviruses and Opportunistic Infections in Los Angeles, United States, this week (25–28 February).

A study in Zambia showed that exclusive breastfeeding ― where a child is fed only breast milk ―  beyond a set time period of four months did not increase the risk of HIV transmission. The study was a collaboration between US universities and University Teaching Hospital in Lusaka, Zambia.

Other studies suggested that continued exclusive breastfeeding could actually improve the survival rate of HIV-positive children.

Three studies in Malawi, Kenya and Uganda, sponsored by the US Centers for Disease Control and Prevention, found that stopping exclusive breastfeeding a few months after birth increased the risk of severe diarrhoea in the infant.

The Malawi study, of over 3,000 infants, reported that the risk of diarrhoea-related death doubled and the incidence of hospitalisation for diarrhoea was thirty times higher if breastfeeding was stopped early.

Speaking at the conference, Hoosen Coovadia, from the University of KwaZulu-Natal, South Africa, illustrated the difficult balance that must be struck.

He said that if women in developing countries were advised to continue exclusive breastfeeding, 300,000 children would become infected with HIV each year — but 1.5 million deaths from common diseases such as diarrhoea would be averted.

"So on the balance of probabilities for poor women in the developing world, there is no other choice [than to continue breastfeeding]," Coovadia said.

Many national government guidelines are based on a 2006 WHO statement which recommends that HIV-positive women breastfeed for six months if no alternative is available.

But Moses Sinkala, previously of the Zambian Ministry of Health, said that the recommendations are difficult for mothers to interpret. He said there is a need for clearer information on the consequences of continued breastfeeding, which the Zambian study went some way to addressing.

"What we have learnt from this study is that breast milk is more than just food for the baby," Sinkala told SciDev.Net.