In 1983 the American pharmaceutical company Abbott applied to have their AIDS screening test patented for the French market. But this met a barrage of opposition from their French counterparts, Diagnostics Pasteur, whose own screening test was still under development. Letters quoted by Le Monde newspaper show the role played by the health secretary and the prime minister in deliberately delaying the patenting of Abbott's test. In 1983 Diagnostics Pasteur applied for a patent in the United States, which was only granted in 1986. The systematic testing of all blood donors for AIDS was recommended by the World Health Organisation in 1985.
Heating is a means of neutralising possible infectious agents in blood.
This meant that one HIV positive blood donation was enough to contaminate an entire pool. Even though there were repeated warnings that collecting blood from prisoners should be stopped, it actually increased. The CNTS also refused to import blood to offset a situation of temporary scarcity. It was not until seven years after the scandal broke out that Parliament first passed a law creating a compensation fund for the victims. It took another eight years to compensate 3,846 victims or their families.