Foreigners hoping to visit, study or work in China have a right to know whether the fact that they are carrying an illness could block them at the border, say activists.
The issue arose after a 25-year-old Australian man of Chinese ancestry was refused a student visa.
James Lau said he can think of no reason why the authorities would turn down his application for a student visa other than the fact he has hepatitis B.
Lau said the Chinese embassy in Canberra, Australia, refused his application in July. He had hoped to travel to China to study Chinese.
"I was so disappointed because going to China has been my dream since childhood," said Lau, who quit his job in Sydney in order to travel.
Lau was not given a reason why his application was turned down but he feels sure it must be because he declared on his application that he had Hep B.
"There couldn't be any other reason," he said. "Refusal of a student visa to China has seldom happened before."
Critics point out that China has 120 million Hep B carriers, one-third of the world's total, and say it would be absurd to refuse someone entry to the country because they have the illness.
Hao Yang, deputy director of the Disease Control and Prevention Bureau under the Ministry of Health, said China does not have a travel ban against Hep B carriers and said most Hep B-related discrimination cases happened in the workplace and in schools.
An e-mail inquiry from China Daily to the embassy seeking clarification on why Lau's application was rejected has not been responded to.
According to the current Implementation Rules of the Law on Control of the Entry & Exit of Aliens enacted in 2004, foreigners who suffer from mental diseases, leprosy, HIV/AIDS, venereal diseases, open tuberculosis and such infectious diseases shall not be permitted to enter China.
Lau said he believed the Chinese embassy might have included Hep B in the category of "such infectious diseases".
Wang Zhao, vice-president of the China Foundation for Hepatitis Prevention and Control, said she had "never heard of any cases of the sort".
"Hepatitis B has never been listed as a condition that warrants entry refusal," she told China Daily.
Hep B is a blood-borne infection that is transmitted through exposure to infected blood or body fluids containing blood, according to the World Health Organization. No country has rules in place preventing carriers from entering.
Lu Jun, a Beijing-based activist working for the rights of people with physical and mental disabilities, said ambiguity in China's visa approval rules should be cleared up.
"The authorities should clarify the exact conditions that lead to entry denial," he said.
On the application form, people are asked if they have any conditions listed on the form but they are also told: "If you select 'yes', you do not lose eligibility for visa application".
This seems to directly contradict the rules.
"It was very confusing," Lau said.
"I wouldn't call it discrimination against Hep B carriers but China has a duty to clarify its visa rules, especially for applicants with an infectious disease, since they are asked to disclose their private medical status," Lau said.
The Ministry of Health said in 2007 China would lift its ban on the travel of HIV-positive foreigners. However, two years later, the country is still among about a dozen worldwide with such a ban.