Hepatitis B mutations discovered in Dublin

A MUTATED form of the viral illness, hepatitis B, has been identified in two Dublin patients, the first such cases to be found in Ireland.

Some hepatitis B mutations isolated in other countries have been found to cause infection despite vaccination. Some forms have also gone undetected in patients despite the use of established tests for this illness.

"If we've got this mutation there is no reason to expect that we won't get the other types," said Dr Alan Shattock, a senior lecturer in the department of medical microbiology at University college, Dublin. He identified the virus in collaboration with Dr Aidan McCormick, of St Vincent's Hospital, and Dr Bill Carman, of the Glasgow Institute of Virology. Their results will be published shortly in the international medical journal, Hepatology.

The appearance of mutated hepatitis B forms could bring into question the effectiveness of vaccinations now in common use here. A wide range of employees, including gardai, doctors, prison officers, psychiatric nurses, surgeons and other health care workers are routinely offered hepatitis B vaccination to protect against possible infection.

Hepatitis B is a virus that affects the liver. The majority of patients experience only minor symptoms after exposure, but 10 per cent of people go on to develop chronic infection, leading to cirrhosis or liver cancer.

Chronic individuals are highly infective, with transmission possible from any bodily fluids. Sex is the "number one route" for transmission in the Western world, Dr Shattock said. It can be transferred during organ donation, blood transfusions and even through bites if saliva containing: the virus is carried across.

In Ireland, intravenous drug abuse is the main transmission method, Dr Shattock said. Hepatitis B infection is endemic among the drugusing population in Irish prisons and in psychiatric hospitals, where patients often bite one another. Many patients attending sexually transmitted disease clinics are also infected with this virus, he said.

Dr Shattock presented information about the two infected patients during the Academy of Medical Laboratory Science annual conference yesterday in Dublin. One patient had the mutated virus and then passed it on to a partner.

"It proves for the first time that this mutant is independently transmissible and fully able to cause disease," he said.

It was likely, he said, that current vaccines would be effective against the mutant virus identified in the Dublin patients, but not against other mutant forms. Should these forms appear here, then new vaccines would have to be introduced to provide protection. "It means we will have to be more vigilant."