There has been a 67% increase in HIV infections so far this year
Chinese health officials have estimated that 30,000-50,000 people could have been infected with HIV, the virus that leads to Aids, through blood transfusions.
China's Deputy Health Minister, Yin Dakui, said most of these people were blood donors, many of whom had sold blood to illegal collectors.
Officials said that over 300 people had been affected there in one village alone.
Cover up
For months the Chinese Government has tried to cover up the HIV blood scandal in Henan. Even now officials try to stop reporters visiting the area.
But last month, the government acknowledged there was a problem.
Now Mr Yin, who was sent to the region to investigate, has told reporters in Beijing that in the worst affected village close to 20% of residents had HIV, and of those who had sold blood, 43%, or almost 250 people, were infected.
He said a survey in other local villages showed a similar incidence.
For many years, villagers in Henan sold blood to illegal traders who pooled the blood from different donors in large vats, extracted the plasma, and re-injected the remaining mixture into the donors.
Screening programme
The Chinese Government recently announced it would spend over $100m to improve the screening of blood used in transfusions, raising some hopes among Aids experts that the scandal may be forcing the authorities to take the problem more seriously.
The government says intravenous drug use is still the main source of HIV infection, and Mr Yin said more than a third of drug users still share needles.
He also gave new figures suggesting that only 9% of Chinese prostitutes insisted that their clients used condoms - an alarming statistic in a nation where prostitution is widespread.
The minister said HIV infection among prostitutes rose to 1.3%, a level which experts say could lead to a rapid spread of the virus.