Eight Years of Surveillance of Patients Hospitalized with Hepatitis: Interpretation of Data in Light of Epidemic Parenteral Dmg Abuse and Availability of Testing for Hepatitis-associated Antigen

Abstract

As part of a continuing program of surveillance, 370 patients hospitalized with acute viral hepatitis were grouped epidemiologically and tested for hepatitis-associated antigen (HAA) by a modified immunodiffusion method. HAA was detected in the serum of 54% of the 104 patients believed to have acquired hepatitis through admitted parenteral drug abuse. Patients unaware of (or denying) suspected parenteral exposures were HAA-positive significantly less often (P = .02), although the rate of detection was 40%. Among patients who had had transfusions, two of nine with incubation periods of less than 45 days were HAA-positive, but the average incubation period of HAA-positive cases, 92 days, was 21 days longer than that of HAA-negative cases (P < .005). Hospital personnel accounted for 7% of the hospitalized cases, and although few could identify a specific parenteral exposure, 65% were HAA-positive. The proportion of all patients hospitalized with hepatitis who acknowledged parenteral drug abuse rose from an average of 4% in the years 1963–1966 to 30% in 1967–1971, a striking increase that may have contributed to urban endemicity of HAA-positive hepatitis.