Trends in intravenous drug abuse as reflected in national hepatitis reporting.

A procedure for obtaining an indicator of trends in illicit intravenous (I.V.) drug use-a form of drug use which is very harmful and difficult to measure-has been developed using national hepatitis surveillance data. Hepatitis reports are separated into two groups: one containing mostly cases related to transmission via I.V. drug use and the other containing cases related to transmission via personal contact and blood transfusion. The analysis of ten years of national hepatitis reporting (1966 to 1975) shows an almost ten-fold rise in drug-related hepatitis cases from 1966 to 1972. In the last three years the number of cases has declined but remains substantially greater than the pre-epidemic levels. The rise in I.V. drug-related cases began in the 1960's among minority groups living in the center cities of the East and West Coasts and spread during the 1970's into the suburbs of these cities and into metropolitan areas throughout the United States. Limitations of this indicator of I.V. drug use relate to the characteristics of the surveillance system and to the underlying relationship of hepatitis to I.V. drug use.