Worldwide air travellers booking online may soon be asked to tick a box to make a $2-per-flight donation towards fighting disease in the developing world in a UN-backed initiative that aims to raise more than $1bn (€784m £722m) a year, writes Harvey Morris .

With government overseas aid budgets under pressure because of the global financial crisis, the United Nations is turning to private industry and individuals to finance the battle against Aids, tuberculosis and malaria, which collectively kill 6m people a year.