The Chinese government has lifted a ban on allowing foreigners with HIV/AIDS, sexually transmitted diseases, and leprosy into the country. The rule had been in place for two decades. The government said the ban was an inconvenience that didn’t control disease. China had been planning to change the law for several years, and had lifted it for big events, like the 2008 Summer Olympics in Beijing. The new rule comes just in time for the Shanghai World Expo, to begin in a few days. Earlier, a Chinese professor explained, China viewed HIV/AIDS as a disease that came from living “a corrupted lifestyle,” but the government has changed that view.