BEIJING, May 31 (Reuters) - Employers in China, where ignorance about hepatitis B has led to widespread discrimination, have been ordered to grant equal job opportunities to some 120 million carriers of the virus. Employers may not decline job applications or fire employees on the grounds that they are infected unless their job might help spread the virus, the Ministry of Labour and Social Security said in a notice posted on its Web site (www.molss.gov.cn). "At present, cases of hepatitis B carriers' employment rights being infringed come up from time to time because of the public's misunderstanding of the disease," the ministry said in the notice to provincial governments. Many Chinese employers, including government offices across the country, have made a negative hepatitis B test compulsory in recruiting new staff. There have also been reports of schools expelling students found to be carrying the virus. Symptoms include inflammation of the liver and jaundice and the disease can be spread by contact with blood of, or unprotected sex with, an infected person. The government has revised its health standards in recruiting civil servants to open the door to hepatitis B carriers, but the ministry's notice indicated the problem was still widespread.