Students with the highly infectious liver disease hepatitis B may soon be allowed to train as doctors after a review by the Government and universities, The Times Higher can reveal.
At the moment students are not admitted to medical school if they test positive for the hepatitis B virus, which is thought to be the leading cause of liver cancer and is about 100 times more infectious than HIV.
But the Bloodborne Virus Protocol Development Group - a high-level health group that is advising the Government - is considering changing the rules to avoid discriminating against infected students.
Under the new plans, medical students would also be screened for HIV and hepatitis C for the first time - but a positive test would not mean they could not train as a doctor.
The news has alarmed patient groups.
Michael Summers, chairman of the Patients Association, said: "If it becomes public knowledge that students who will later qualify as doctors have an infectious disease people will be very disturbed - quite naturally."
The protocol group, which is led by the Council of Heads of Medical Schools, was set up in response to a new ruling from the General Medical Council. The ruling says that students can be trained as doctors without carrying out "exposure prone procedures".
A source close to the group said there was some debate about which procedures this should cover.
It is likely that an infected doctor would not be allowed to deliver babies, perform surgery or be involved in trauma cases, but they would be able to perform procedures such as taking blood.
The source said that hepatitis B was the disease that caused most concern within the group, because it was a "thoroughly nasty virus" and much easier to contract than either HIV or hepatitis C.
The source added: "This is never going to be an easy issue to resolve. If you went to your doctor and he cut himself while taking blood you would want to know he didn't have hepatitis B or HIV. But if you were bleeding to death you wouldn't care."
Julius Weinberg, an infectious disease expert and pro vice-chancellor for research at City University, said: "I think it reasonable to expect potential doctors to be aware of any infectious disease they might have."
He added that an infected doctor could take "appropriate steps" to ensure they were not putting patients at risk.
The British Medical Association students committee welcomed moves to let students with hepatitis B study medicine, but it attacked plans to screen students for HIV at the start of their courses.
Jonathan Beavers, deputy chairman of the committee, said the policy was "ridiculous and ill-thought out".