From the editor

The third immigrant disease

‘This is the third major disease to be obviously traceable to migration. According to the Public Health Laboratory, in each of the last four years 95% of all new cases of hepatitis B in this country came from abroad.’¹ Thus the daily press represents the issue of the hepatitis B virus (HBV) infection in the UK – a disease which is now both preventable and eminently treatable.

Effective prevention of HBV infection has been available for over 30 years. The World Health Organisation (WHO) recommended a universal HBV vaccination policy for all countries, but this has not been adopted in the UK and some other northern European countries. Decisions on universal vaccination balance incidence and prevalence, and costs of prevention versus costs of treatment; clearly these vary hugely, particularly with geography. In high incidence countries, the far east for example, with chronic carriage rates exceeding 10% of the population, HBV immunisation in childhood strikingly and rapidly reduced not only HBV infection but also HBV-dependent hepato-cellular cancers.² In the US, the elimination strategy commenced in 1991 was associated with a reduction in the incidence of HBV infection by 75%, using a combination of universal vaccination at birth, a catch-up programme of immunisation of adolescents, and finally ante-natal screening of mothers – since neonatal immunisation of neonates born to HBV carriers is highly effective in preventing mother-to-child transmission.³ The reluctance of the UK to embark on a universal vaccination strategy is based on our very low prevalence of chronic HBV carriage – recent figures indicate about 0.5% prevalence, which is lower than the US at the time they initiated their immunisation programme and far lower than in Asia. In times of austerity it will take progressively stronger arguments to push forward innovations of uncertain cost-benefit in the UK.

Currently the Department of Health (DoH) advocates protection against infection by identifying and vaccinating adults in high risk groups, such as close family contacts of chronically infected carriers, injecting drug users, prisoners and prison staff, and travellers to high endemicity areas, as well as at-risk babies identified by antenatal maternal screening.⁴ When the latter is performed in a timely fashion, percentage protection rates are in the high 90s. Pregnant women in the UK in NHS facilities are universally screened for the virus – and in London the HBV carriage rate in pregnancy is about 1%.

Interestingly, the DoH website NHS Choices offers advice on HBV vaccination, but makes no specific mention of the greatest at-risk group: immigrants to the UK.⁴ A recent technical report from the European Union (EU) estimated that there is a carriage rate of about 4% among the three largest migrant groups in the UK. Anticipated future immigration from newly joined eastern European states of the EU may bring in further groups of individuals, including those with a similar or higher prevalence.⁵

The immigrant population in the UK would benefit from an HBV programme in two ways. Having a significant proportion of carriers, they are clearly a group in which the risk of uninfected individuals contracting the disease from close contacts is higher than in the general UK population. Therefore immunisation of those at risk should be strongly encouraged. Furthermore, they are a population in which screening for HBV could have a direct benefit via identification of asymptomatic chronic carriers. Such people have an increased morbidity and early mortality rate, and effective antiviral treatment is now available. Significantly, a recent Dutch study – though theoretical rather than observational – suggested that screening and early treatment of migrants for chronic HBV would be cost-effective, judged both by saving healthcare costs and preventing liver-associated premature death.⁶ Furthermore, reducing the prevalence of HBV in any segment of the UK population has the additional benefit of reducing the risk to the general population.

There is, of course, the dilemma of finding societally acceptable means of identifying the at-risk individuals among the immigrant population. Initiatives such as the New Entrants Screening Service in Berkshire⁷ – which provides primary and preventative healthcare to its new migrant population, addressing issues such as tuberculosis screening, BCG immunisation and HIV assessment – can extend to HBV and thereby contribute to reducing HBV disease, both in immigrants and in the general population.

Such approaches, however, will never achieve the protection rates that universal vaccination would offer, though they would be a small step in the right direction. As to the goal of universal immunisation in the UK, we close with an elegant extract from English's article ‘Should universal hepatitis B immunisation be introduced in the UK?’ published in the Archives of Diseases of Childhood in 2006. His abstract was a short one: ‘Yes. But how?’⁸