A register of all drug abusers committed to the Copenhagen prisons has been kept by us since 1964. Otherwise, there is no official monitoring of drug abusers in Denmark. The number of criminal drug abusers has risen appreciably since 1964 and, within the same period, the number of addicts using injections has more than doubled (Table 1).
The first ten cases of hepatitis to develop in imprisoned drug abusers were diagnosed in 1967; each was admitted to Vestre Hospital (Copenhagen Prison). This number increased during the ensuing years, and, in 1970, a total of 131 drug abusers with hepatitis had been admitted to Vestre Hospital (readmissions not included) (Table 1).
Since November 1969 we have collected blood routinely from all drug abusers immediately upon their commitment to prison with the aim of detecting hepatitis associated antigen (HAA) and determining serum glutamic pyruvic transaminase (SGPT). We determined HAA by immunoelectrophoresis according