NAIROBI - Multinational food companies have long been under attack for pushing milk powder at mothers who do not need it and cannot afford it. But the anti-bottlefeeding lobby is now in a quandary. Evidence is growing that around half the 3.8m children infected with HIV contracted the infection at their mothers’ breast.

In rich countries HIV-infected women can be told to bottlefeed their babies. But the problem is more complicated in the developing world, where over 90% of child infections occur. The risks of bottlefeeding remain—breastmilk protects infants from all manner of other infections—and so does the cost.

Moreover, in even the most heavily infected areas, 70% of mothers do not carry the virus and, for them, breastfeeding is still by far the best option. The difficulty is that the vast majority of pregnant women in the developing world have no idea whether or not they are infected. Promoters of breastfeeding worry that large numbers of healthy women will switch to bottlefeeding just in case. Others fear that if bottlefeeding becomes a badge of infection, even women who know they are infected will continue to breastfeed to avoid being stigmatised.

Many of them have no alternative. Even where mothers have access to clean water to prepare artificial milk, a year’s supply of powdered milk can cost over $700, more than the GNP per head in some heavily infected countries. Ironically, the cost is pushed up by high taxes, imposed to discourage bottlefeeding.

A few countries, such as Thailand, offer testing to all pregnant women, and give those who are HIV-infected free milk powder. But in Africa, where a woman is likely to be pregnant three times as often as in Thailand and where HIV infection ranges up to 25% of the population against Thailand’s 2%, that solution is an expensive and distant dream.