Sir, the sentiments expressed by P. Tweddell (BDJ 2005; 199: 128) are worthy of further comment. The Centers for Disease Control, Atlanta, USA stated in December 2003:

'The Hepatitis C virus appears not to be transmitted efficiently through occupational exposure to blood.'

'No studies of transmission from HCV-infected dental care personnel to patients have been reported, and the risk for such transmission appears limited.'

The Centers noted that transmission from HCV-infected surgeons during invasive procedures was on average 0.17%. Given these findings, the GDC's advice that HVC-infected dentists should cease practising appears to be harsh and not supported by the current evidence.

The Chief Executive and Registrar of the General Dental Council, Antony Townsend responds: Thank you for the opportunity to reply to the recent letters to the BDJ on the subject of blood borne viruses.

The GDC's purpose is to protect patients. To do this we must make a number of checks on each applicant's suitability for registration. We ask all applicant dentists to submit a health certificate as evidence of their good health. This is not new, but last year we made the check more robust by stipulating the sorts of health issues we would expect to be told about. Currently, we require evidence of TB and hepatitis B immunity. This is consistent with the practice of NHS employers and dental schools. While its principal purpose is to protect patients, establishing immunity is also in the clinician's interests.

Mr Tweddell is not right to say that a dentist infected with a blood borne virus 'would be legally obliged to inform the GDC, who would subsequently advise the dentist to cease practice'. The GDC's guidance is that a dentist who knows they are, or thinks they may be, infected with a blood borne virus or any other transmissible disease or infection, has a duty to seek and follow medical advice. The medical adviser will be obliged to follow the procedures clearly outlined by the Department of Health. These procedures are under continual review by a range of expert groups including the Expert Advisory Group on AIDS (EAGA), the Advisory Group on Hepatitis (AGH) and the UK Advisory Panel for Health Care Workers Infected with Blood-borne Viruses (UKAP). The GDC expects each registrant to ensure that the national guidelines on infected health care workers are followed for the protection of patients. Since the majority of procedures carried out by dental surgeons are exposure-prone as defined by the Department of Health, it is inevitable that on some occasions the individual will have to cease the clinical practice of dentistry either temporarily or permanently.