Disease is not a justification for discrimination UK opposition-party leader Michael Howard last week seized on public fears about immigration and health when he announced that his party would deny visas to prospective immigrants who test positive for tuberculosis (TB). HIV tests would also be mandatory under the Conservative policy, but visas would not necessarily be withheld. This plan, says Howard, is a strategy to minimise the public-health threats posed by immigrants. But the intense debate these proposals have generated--mainly because of their similarity to current government policies--has unfortunately obscured a more important point: that disease must not be a basis for discrimination. Infections imported by immigrants do not have a significant impact on public health. In the UK, for example, migration has been blamed for a steady increase in newly diagnosed HIV infections, but absolute numbers remain small. Percentage calculations, such as those cited in Howard's publicity material, exaggerate the relative burden of immigration-related illness. According to the Health Protection Agency's most recent report, the number of newly diagnosed HIV infections thought to have been contracted outside the UK in 2003 number only around 3000. Reacting to public fears over perceived threats, countries including Canada, USA, Australia, and New Zealand, have adopted stringent policies for compulsory screening of new entrants for TB and HIV. But the only UK public inquiry into the issue came out firmly against the idea, concluding that "there is no evidence to suggest that such a policy would be effective at protecting public health". The All Party Parliamentary Group on AIDS, which set up the inquiry, expressed grave concerns that the government was seeking ways to "exclude vulnerable individuals on the basis of poor health". Policies that discriminate against visa applicants on the basis of disease risk stigmatising entire sections of society. But technical weaknesses in health-check policies also preclude achievement of their alleged protective purpose. By selecting just two diseases for scrutiny, and specifying that only arrivals from non-EU countries will be tested, the UK policies ignore some of the most immediate risks. The former communist states of eastern Europe have some of the highest rates of TB in the world. But visitors from these countries will be under no obligation to undergo testing before entering the UK. To base any decisions on the presence or absence of illness is appallingly discriminatory and emphasises the stigmatising nature of political debate. This is politics that undermines the peaceful and civilised values of society. And our politicians are shamelessly exploiting these now brittle principles.