Hepatitis B outbreak in a drug trials unit: investigation and recommendations

In autumn 1990 three young men developed acute hepatitis B. They belonged to a group of 24 young male volunteers who had taken part in a trial in a residential unit for drug trials in July and August 1990. A further case of acute hepatitis B and a carrier of hepatitis B e antigen (HBeAg) were detected by serological testing of the volunteers. Volunteers, in two groups of twelve, had occupied the unit at different times during the trial. The four cases occurred in the group that contained the HBeAg positive carrier. The carrier had also taken part in two trials on the unit in 1989. He was HBeAg positive then, but transmission of hepatitis B virus (HBV) did not occur. Although blood samples were taken in each of the three trials, intravenous cannulas were used only in the 1990 trial. It is likely that HBV was transmitted by blood to blood contact between volunteers when blood was sampled through cannulas during the trial. This outbreak might have been prevented. If an infection control policy had been applied to avoid hazardous practices, and volunteers had been screened for HBV before entry and the carrier excluded (as recommended by the Association of Independent Clinical Research Contractors), the outbreak would not have occurred. Volunteers for drug trials in residential units should be screened for HBV, human immune deficiency virus (HIV) and hepatitis C virus (HCV), and those found to be infected should not be accepted.(ABSTRACT TRUNCATED AT 250 WORDS)