The vast sums of money ploughed into efforts to fight diseases such as Aids, TB and malaria in the last 10 years have saved many lives but have also sometimes undermined health systems in poor countries, according to a survey by the World Health Organisation and others published today. A worldwide outcry around the turn of the millennium over the plight of people in Africa dying of Aids, a disease kept in check with drugs in rich countries, triggered a rush to fund big disease-fighting programmes on the part of western governments, aid organisations and philanthropic donors such as the Bill and Melinda Gates Foundation. But until now, there has been little attempt to find out how well the money has been spent and what impact the focus on high-profile diseases has had on the everyday business of hospitals, clinics and overworked healthcare staff in the poorer countries.