The Chinese government announced Tuesday the lifting of the 20-year-old ban on entry for foreigners with HIV/AIDS, sexually transmitted diseases and leprosy.

According to a statement released Tuesday by the State Council, after gaining more knowledge about the diseases, the government has realized that such ban has a very limited effect in preventing and controlling diseases in the country. It has, instead, caused inconvenience for the country when hosting various international activities.

The revision comes days ahead of the opening of the Shanghai World Expo. The government temporarily lifted the ban for various large-scale events, including the 1990 Beijing Asian Games, the Fourth World Conference on Women in 1995 and the 2008 Beijing Olympics.

Mao Qun'an, spokesman for the Ministry of Health, said the groundwork for the lifting of the ban began years ago. The ministry had been advocating lifting the restriction since the Beijing Olympic Games. It took a few more years only because of the necessary procedures.

The two decisions altered regulations for the Border Quarantine Law and the Law on Control of the Entry and Exit of Aliens, which set down the ban in the 1980s.

The previous ban was made in accordance with the "limited knowledge about HIV/AIDS and other diseases," the statement said.

Zhang Beichuan, a medical professor with Qingdao University and a front-runner in advocating the rights of people living with HIV (PLWHIV), said it's the move is huge progress.

"Previously, China viewed HIV/AIDS as an imported disease related to a corrupted lifestyle. But now the government handles it with a public health perspective," he said.

He Tiantian, a woman in her 30s living with HIV and an AIDS activist, said, "This revision shows us a silver lining, because we have been advocating for the rights of PLWHIV for years, and now we know we didn't do it in vain."

"However, it still takes time to end discrimination, but the change in the government's stance will help change the public's attitude towards this group of people," she added.

According to the health ministry, the estimated number of people living with HIV in China had reached 740,000 by October 2009, with deaths caused by AIDS totalling 49,845 since the first case was reported in 1985.

The statement said the lifting of the ban won't bring an outbreak of disease in the country as scientific research has proved daily contact doesn't cause infection.

HIV/AIDS is usually transmitted through blood, sex and from mother to infant. Leprosy is usually transmitted through skin injuries.

Meanwhile, the government also narrowed the restrictive scope for mentally ill and tuberculosis patients to only "severe mental patients" and those with infectious tuberculosis.

According to the statement, not all tuberculosis diseases are infectious and mental patients won't harm the country's social order and personal safety.

Statistics show that currently 110 countries and regions around the world have no ban on entry for HIV/AIDS carriers. The United States and Republic of Korea both lifted the ban in January.