Acute viral hepatitis 5 years after start of vaccination campaign in Zürich

[Prevention of hepatitis B (excluding vaccination)]

The immunisation programme against hepatitis B should not neglect other preventive measures. The main measures are: Always use condoms with casual sexual partners, do not exchange syringes or injection material, always apply universal precautions with blood and other biological liquids as these must always be considered potentially infectious.

Selective risk group strategies in Europe

Most countries in northern and western Europe belong to areas with a low endemicity of hepatitis B virus (HBV). When HBV vaccines became available, these countries adopted a vaccination strategy that targeted groups at high risk of hepatitis B. However, it became obvious that this strategy, despite giving good protection to those who had been vaccinated, had largely failed. This was firstly because, with few exceptions (e.g. haemodialysis patients and haemophiliacs), only medical and dental workers were vaccinated in any great numbers, whereas only a few individuals in other risk groups were reached. Second, it was found that less than half of all hepatitis B cases occurred in individuals in typical high-risk groups. In Germany, for example, about three-quarters of all infections occur in people who would never be reached by the high-risk vaccination strategy, most of these individuals having been infected by heterosexual contact. Thus a universal vaccination strategy has to be implemented to control the spread of hepatitis B in the population and to eventually eliminate the disease.

Hepatitis B: transmission by sexual contact and needle sharing

In the Western world most cases of hepatitis B virus (HBV) infection are acquired through sexual intercourse and through needle sharing by intravenous drug users (IVDU). The major risk factors for HBV infection in homosexual men include the number of sex partners and receptive anal intercourse. In heterosexuals, this risk also rises with an increasing number of sex partners. IVDU consistently show the highest HBV infection rates in Europe and North America, presently accounting for 25 to 50% of all hepatitis B cases. Infection with the human immunodeficiency virus affects the course of HBV infection as well as the immunological response to hepatitis B vaccines. Thus, in the industrialized world, interventions against HBV infection should primarily be targeted to homosexual men, heterosexuals with multiple partners, and IVDU.

The changing epidemiology of acute type B hepatitis: results of an 11-year prospective study in Padua (northern Italy)

The epidemiological pattern of acute type B hepatitis has been investigated in 1,107 consecutive patients during an 11-year prospective study conducted in Padua (Northern Italy) between 1978 and 1988. Remarkable changes were observed: 1) the attack rate of the disease increased significantly (p less than 0.05) between 1978 (18/10(5) inhabitants) and 1982 (29/10(5) inhabitants), particularly in male subjects and in the 15-19-year age group. The proportion of drug addicts also increased from 8.8 to 42% (p less than 0.05). These changes coincide in time with the spread of parenteral drug abuse in our area; 2) the attack rate dropped significantly (p less than 0.05) between 1983 and 1988 reaching the lowest levels ever observed before (4.7/10(5) inhabitants). The proportion of drug addicts decreased significantly (p less than 0.05), although the number of subjects starting narcotic abuse did not decline in recent years. Two major events could explain this pattern: a partial exhaustion of the susceptible population after spread of infection among drug abusers and, later on, the changing risk behaviours observed in our drug abusers after the AIDS prevention campaign. Other factors, including vaccination of some high risk groups, could have contributed to these changes.