More than third of world’s population has been infected with hepatitis B virus

Editor—The news items on the prevalence of hepatitis B infection is incorrect and the accompanying artificially coloured photograph is misleading.¹ Electron micrographs are usually negatively stained (figure).

More than a third of the world’s population has been infected with hepatitis B virus.² It is estimated conservatively that there are 350 million chronic carriers of hepatitis B virus worldwide. Many are lifelong carriers, although not all are infectious, and some clear the virus after varying intervals. About a quarter of carriers develop serious liver disease as a result of the infection, including chronic hepatitis, cirrhosis, and primary liver cancer. The World Health Organisation estimates that hepatitis B results in 1-2 million deaths every year worldwide.³

One million people are estimated to be infected in the WHO’s European region each year. Of these, about 90 000 will become chronically infected and about 22 000 will eventually die from cirrhosis or liver cancer.⁴ The sexual route is the most common means of spread of the virus in Europe and North America. Those aged 15-24 are at the highest risk. In 1992 the World Health Assembly recommended that all countries should introduce hepatitis B vaccination into national immunisation programmes by 1997. Regions with a low prevalence of infection, such as Europe, North America, and Australia, should consider immunisation of all adolescents as an addition or alternative to infant immunisation.⁵ This policy has been implemented by over 95 countries and most European countries (but not by the United Kingdom).

Figure.

Electron micrograph of hepatitis B virus (double shelled particle) and excess surface antigen protein (tubular forms and small spherical particles) (magnification ×252 000)