An outbreak of hepatitis B in a dental practice.

In September 1978, cases of hepatitis B in two patients treated by the same dentist led to investigation of a dental practice in Baltimore, Maryland. The dentist had had acute hepatitis B in June 1978 and had remained positive for hepatitis B surface antigen and hepatitis B e antigen over the ensuing 6 months. He had continued to work while infected, wearing surgical gloves to minimize the risk of transmitting infection. Serologic follow-up of 764 patients showed that a total of six patients, three of whom were symptomatic, had developed hepatitis B infection after dental treatment. All six were among a group of 395 patients treated before the dentist began wearing gloves. In this group, patients having highly traumatic dental work (attack rate 6.9%) were at significantly higher risk than patients having either less traumatic work (attack rate 0.5%) or nontraumatic work (attack rate = 0, p less than 0.02). None of 369 patients treated only when the dentist wore gloves became infected, suggesting that gloves could reduce the risk of virus transmission by the dentist.