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Exposure to viruses depends on "gloves or instruments being contaminated from a previous patient", argues Prof. David Evans following 22,000 patients being recalled

Following the recall of 22,000 dental patients following dental malpractice Professor David Evans, of the University of Warwick's School of Life Sciences, has said that the exposure to viruses "depends upon the dental procedures involved and the likelihood of gloves or instruments being contaminated from a previous patient".

Professor Evans' full comment:

There are two possible sources of blood-borne viruses that could be acquired during a visit to the dentist. The first is from the dental practitioner, when a minor cut through a protective glove could lead to direct exposure of the patient’s blood with that of the dentist (although reports from NHS England suggest that this dentist was not infected with any blood-borne viruses). The second is through exposure of the patient’s blood to gloves or instruments that have been contaminated with blood from a previous patient.

The three most significant blood-borne virus infections are HIV, HCV (hepatitis C virus) and HBV (hepatitis B virus). Adherence to normal protective measures such as hand washing, changing gloves between patients, and using sterile instruments is usually sufficient to prevent patient to patient transmission of any of these three viruses within a dental surgery. That is why these protective measures are used. Reports from NHS England suggest that the dentist was not infected with these viruses.

Although globally very large numbers of people are infected with HCV and HBV, the incidence in the UK of individuals carrying these viruses (which may cause lifelong infection) is low. HBV prevalence is thought to be below 0.5% and HCV prevalence between 0.5 and 1%, although the prevalence varies between communities. Potential exposure therefore depends upon the dental procedures involved and the likelihood of gloves or instruments being contaminated from a previous patient. Many individuals exposed to HBV and HCV as adults will naturally clear the infection. A proportion will become chronically infected and may develop liver disease. Testing for infection is likely to involve screening for viral protein or nucleic acid in the blood. There is an excellent vaccine to prevent HBV infection which many who have travelled abroad will have been immunised with. There is no vaccine for HCV but newly developed and licensed anti-viral drugs against this virus are effective.

To speak with Professor Evans please contact:

Tom Frew - International Press Officer, University of Warwick;

a dot t dot frew at warwick dot ac dot uk

+44 (0) 2476575910

Professor David Evans;

D dot J dot Evans at warwick dot ac dot uk

Click here for more information on Professor Evans.