When walking down a narrow alley in a small north Chinese village in the mid-1990s, Dr Gao Yaojie heard a child crying desperately for its mother. “When I entered,” she later recalled, “I saw that the mother had hanged herself and the body was stiff.” The father had already died and the family was destitute after being defrauded by quack doctors. In another village in Henan province, half the houses hung white paper emblems outside to signify a death. The villagers called it the “nameless fever”, and orphans were left to scavenge for food in the fields. Gao, who has died aged 95, became their resolute champion, having discovered that Aids was raging in many rural districts because of contaminated blood. Before long she was banned from giving interviews to the press. Henan health officials tried to challenge the diagnosis – because they were responsible. Driven by the entrepreneurial enthusiasm of Deng Xiaoping’s China, they ordered local medical centres to “focus on blood collection” so that the products could be sold. Often in league with …