Leading Tuberculosis Experts Explore Shortcomings in Current Immigrant TB Screening Policy

Leading scientists and experts in the field of tuberculosis (TB) met recently to discuss how to improve national prevention strategies for the control of TB. The UK is one of few countries in Western Europe which has seen an increase in the number of active TB cases in recent years. The group, chaired by Professor Peter Davies, Consultant Chest Physician at Liverpool Heart and Chest Hospital and Dr Onn Min Kon, Consultant Respiratory Physician at St Mary’s Hospital, is expected to acknowledge recent findings that current UK immigrant screening procedures miss more than 70 per cent of latent TB infection and develop a consensus on how replacing current diagnostic tools with new cutting-edge technology, can reduce disease burden and cost.

TB remains one of the most contagious and prevalent diseases in the world, with approximately nine million active cases globally. It is estimated that there are also about two billion people around the world infected with latent, or inactive, TB. Research shows that in people with latent TB, preventative treatment can reduce the risk of developing active TB by as much as 90 per cent, demonstrating the importance of identifying and treating latent disease.

In Britain, cases of TB increased by almost 50 per cent between 1989 and 2009, with 9,040 cases reported in the UK in 2009. In 2011, TB reached its highest peak in 30 years.

“A significant proportion of active TB cases in the UK stem from immigrants carrying latent TB, whose infections are ‘reactivated’ at some point after they arrive in this country,” said meeting co-chair Professor Peter Davies, Consultant Chest Physician at Liverpool Heart and Chest Hospital. “Compounding this is that the diagnostic test that has traditionally been used for identifying latent TB infection is more than 100 years old, and is often inaccurate. Clearly, this is a two-pronged problem that requires a two-pronged solution – we need clearer strategies for testing for latent disease among immigrants, and better diagnostic tests to enable us to do so.”

The tuberculin skin test (TST), the tool traditionally used to identify latent TB infection, is the oldest diagnostic test in medical practice, and is widely acknowledged to have shortcomings in relation to specificity and is more difficult to administer in practice. To combat the lack of an acceptable test for latent TB, new, highly-specific and faster tests have been developed, known as interferon-gamma release assays (IGRAs). Already widely used in US, Europe and Asia, IGRAs have demonstrated significant value in both accurate diagnosis of the disease and cost-effectiveness of the tests, and data show that this cost-effectiveness would be replicated should IGRAs be used in the UK.

“We urgently need to stem the tide of rising TB cases in the UK,” said meeting co-chair Dr Onn Min Kon, Consultant Respiratory Physician at St Mary’s Hospital. “This is not a problem that can be tackled by healthcare professionals alone – it needs to be a joint effort with policy and society. We look forward to an informative discussion about how best to tackle the influx of TB infection stemming from the immigrant community, and how to incorporate the new, and much more efficient and effective, IGRA testing into our efforts to screen for and prevent the spread of TB.”

QIAGEN is sponsoring this symposium as part of their ongoing commitment to the field of TB.

QIAGEN markets the QuantiFERON-TB Gold, the leading test for detection of latent TB, which has worldwide approvals and is recommended in several national and international guidelines.