Tuberculosis (TB) screening and early detection methods, for professionals working with at-risk populations in the UK.
Tuberculosis (TB) is an infectious disease which can have a slow onset of symptoms and cause poor outcomes for individuals if left untreated. Despite almost all forms of TB being curable, difficulties in detecting TB make screening for TB an important issue in the UK. Globally, the World Health Organisation (WHO) estimated that in 2016 about 10.4 million new TB cases occurred. TB is also the top cause of death amongst infectious diseases with 1.7 million TB deaths worldwide.
Screening a population for TB involves identifying otherwise healthy people who are at an increased risk of developing TB. The National Institute for Health and Care Excellence (NICE) currently recommends that people who are at increased risk of TB are screened in the UK.
Screening for TB can focus on detecting active TB disease or latent TB infection (LTBI). People with LTBI have no symptoms of disease but are at risk of reactivation to active TB, sometimes for decades. LTBI can be detected using tuberculin skin tests (TST) or interferon gamma release assays (IGRAs). Screening for active TB disease of the lungs usually involves Chest X-Rays.
The incidence of TB in England is higher than most other Western European countries. It is important that awareness is raised about TB amongst professionals and the public. The Collaborative TB strategy for England recognises that screening for latent and active forms of TB, alongside awareness raising activities will contribute to lowering the incidence of TB in England.
TB active case finding
Active case finding (ACF) is a strategy used to identify and treat people with TB who would otherwise not seek prompt medical care (Golub and others, 2005). ACF usually focuses on detecting pulmonary TB using chest X-rays or performing a symptom enquiry.
Abnormal results may lead to the collection of patient sputum for further tests. Early detection of TB improves treatment outcomes and prevents the spread of the disease.
- professionals at risk of TB (eg healthcare workers)
- close contacts of patients with TB (if active TB is suspected)
people with social risk factors such as:
- homeless people
- people with drug and/or alcohol problems
- immigrants from countries were TB is common
In some groups, especially the homeless, mobile digital x-ray units are sometimes used for ACF in the UK. This type of service can offer enhanced services including detection, diagnosis and care as well as screening for other relevant conditions.
TB awareness raising
Raising awareness makes healthcare professionals and members of the public more alert of the epidemiology and the various clinical manifestations of TB. This is important because:
- TB can occur in many different forms
- the onset of TB is not always clear
- typical symptoms do not always appear
Maintaining increased awareness of TB can be done through activities such as:
- community group sessions
- the production of information and educational materials in various formats and languages
See below for further information:
- leaflets and videos with educational material on TB (available in different languages)
- support for those affected by TB
- training for professionals working with the general population and high-risk groups
- international awareness raising for TB, World TB day
Educational materials should be in a format and language that target groups can understand. In the UK, several organisations are involved with awareness raising activities including TB Alert and the National Knowledge Service.
Latent TB infection (LTBI)
People with LTBI who are not ill and do not have any symptoms, can become ill as a result of reactivation to active TB years or decades later. It is likely that LTBI reactivation causes most of the active cases in the UK.
Individuals who were born or spend considerable time in a country where TB is very common are more likely to have LTBI. More information about TB in migrants can be found in the PHE TB migrant health guide.
It is not feasible or cost-effective to screen an entire population for LTBI but NICE recommends screening for specific high-risk groups in the UK. These groups include:
- close contacts of patients with TB
- healthcare workers
- immunosuppressed patients (eg those with HIV)
- migrants from countries where TB is common
Screening tests for LTBI include the:
The Collaborative TB Strategy for England 2015 to 2020 recommends systematic LTBI testing and treatment for 16 to 35 year-olds who recently arrived in the UK from high incidence countries (World Health Organisation TB rates of 150/100,000 or over and Sub-Saharan Africa) as a key strategy intervention. There is evidence that LTBI screening for people arriving from areas with a TB incidence of 150/100,000 or more is cost effective for the NHS. New NHS funding has been made available to support the implementation of a systematic LTBI testing and treatment programme in England.
Resources to support the implementation of LTBI testing and treatment in England:
- a short film summarising the national LTBI testing and treatment programme
- an overview of LTBI testing and treatment for migrants
- an LTBI testing and treatment patient information leaflet in 14 languages
- latent TB testing and treatment for migrants: a practical guide for commissioners and practitioners
- a latent TB infection testing and treatment flowchart
- the collaborative tuberculosis strategy: commissioning guidance
- NHS England’s collaborative TB strategy FAQs on commissioning, data returns, information governance and communications
Watch a short animation film explaining testing and treatment for LTBI
In July 2016, PHE, NHS England and TB alert launched a toolkit for supporting the implementation of LTBI access, testing and treatment in new entrants. This toolkit addresses challenges in implementation and provides a range of resources for awareness, communication between providers and patients and patient support during treatment.
A national surveillance and data reporting system for LTBI testing and treatment has been approved by the PHE Caldicott Guardian and Chief Knowledge Officer as well as other national and local information governance leads. This system is also recognised as a mandatory collection under the Standardisation Committee for Care Information of NHS Digital (previously HSCIC). Data transfer and storage strictly follows PHE and NHS guidelines and policies, to the highest level of information governance standards. PHE collects patient identifiable data based on section 251 (National Health Service Act 2006).
The Act says we must communicate to patients how their information is processed and utilised (‘Fair processing notice’), which is included in the LTBI testing and treatment patient information leaflet.
Pre-entry TB screening for migrants
From the late 1960s, UK migrants have been required to have a medical examination for signs of active TB as a requirement of entry into the UK. This form of active screening is conducted using chest X-rays and primarily looks for active TB in the lungs (pulmonary TB).
Screening used to be conducted at London’s Heathrow and Gatwick airports. However, it was deemed that the programme would be more effective if it was carried out before migrants applied for a visa. Therefore, from May 2012, the Home Office replaced the system with ‘pre-entry TB screening’. A systematic review of pre-entry screening programmes was conducted by Aldridge and others.
Applicants who apply for a UK visa for more than 6 months and are resident to a country where TB is common (incidence is over 40/100,000), will be screened for pulmonary TB. Visa applications can only be processed once the applicant has been issued with a certificate of clearance to show they’re free from active pulmonary TB. This TB screening for the UK leaflet describes the processes and requirements for pre-entry screening.
Screening can only be performed by a UK-recognised and quality assured provider. A map view of the listed clinics is also available. PHE works closely with the Home Office to support the development of Quality Assurance systems to ensure that the pre-entry TB screening programme is ‘fit for purpose’ in providing its stated objectives. The UK tuberculosis technical instructions explain the pre-departure screening programme for applicants to the UK and provide guidance for those who conduct TB screening.
The UK works with a number of other countries (Australia, Canada, New Zealand and the USA) in the pre-entry screening. Most of these countries have used a pre-entry screening system for many years and have considerable experience with such a system. Together with these countries, PHE also contributes to joint teaching and training opportunities for panel physicians.
Pre-entry TB screening contributes to the reduction of TB in the UK. However, pre-entry screening can only detect TB among people with active pulmonary disease at the time of screening. Many new cases of TB are a result of reactivation of LTBI in migrants once they are settled in the UK. Therefore, it is vital that migrants settling in the UK and the professionals working with them are made aware of the issues surrounding TB and migrant health, as well as receiving support in access to LTBI testing and treatment.
For more information view the UK pre-entry annual screening reports.