About one quarter of the world’s population is infected with tuberculosis (TB) bacteria. Only a small proportion of those infected will become sick with TB. People with weakened immune systems such as older patients have a much greater risk of falling ill from TB. New figures show rates of TB in England have declined by a third in six years, and are currently at their lowest level in 35 years.
The high rate of tuberculosis (TB) in England is falling. Public Health England’s recent epidemiological report reveals a decline in TB incidence, which peaked at 8,280 in 2011.1Since then the number of people notified with TB fell by 40% to 5,102 people in 2017. At 9.2 per 100,000, it is the lowest rate of TB ever recorded in England and led to the World Health Organisation (WHO) declaring it a low incidence country for the first time.2
Likely factors supporting two thirds of the decline are improved TB control and a reduction of transmission in the UK between 2011 and 2015. A third of the decline could be attributed to decreases in the numbers of migrants from high TB burden countries says the report.
However, despite improvements, there is still more work before TB is fully eliminated in the UK. The decline has been sustained over the past five years but the future of TB in England remains unclear.
TB in the UK, as in much of the world, remains a disease that disproportionately affects the poor. Social risk is a significant factor in determining who is more likely to get the disease.
Helen Clegg, communications manager of UK-based charity TB Alert, points out: “TB is also becoming ever-more associated with health inequality in England, as cases are now seven times higher among the most deprived 10% of the population than the least deprived 10%, and increasingly concentrated in people with social risk factors such as homelessness, substance misuse and a history of prison.”
Inequalities exist in the rate of TB. As a group, people born outside the UK may have seen a bigger reduction in notified TB, but they still have a rate 13 times higher than people born in the UK.
Nearly 13% of people notified with TB in the UK suffer from social risk factors such as homelessness, substance abuse or having been in prison.3
While TB can occur anywhere in the UK, areas where there is the greatest concentration of cases lie in large urban centres, with rates in London, Leicester, Birmingham, Luton, Manchester and Coventry more than three times the national average. Other areas with high caseloads include Bradford, Leeds, Kirklees, Slough and Reading.
Some areas have had notable success in strengthening TB services and there is ongoing commitment and collaboration among healthcare and social care providers that are delivering and organising services.
Although the high rate of TB incidence is dropping, it is doing so unevenly across population groups. Where there is cause for consternation is the unyieldingly high proportion of people experiencing a delay between symptom onset to diagnosis and those (although low) who have multi-drug resistant TB.
There are many barriers resulting in delays in diagnosis for vulnerable groups with variance between them. These are difficult to measure with certainty.
Clinical suspicion is important in diagnosing TB and in areas or in populations with low numbers of cases, TB may not be suspected early on. In addition, in the elderly there are often other conditions present such as chronic lung disease, which make diagnosis more complicated.
Multi-drug-resistant TB is a global problem and in England the proportion with multi-drug-resistance is similar to that of other western European countries. People with drug-resistant TB have more complex treatment and work is needed to ensure treatment completion in this group continues to improve.
At ground level, current NHS structures can only reach those higher risk communities (people born outside the UK) through working with trusted community structures to raise awareness about TB. There is a need as part of wide health system endeavour to increase levels of GP registration.
Outreach could include helping migrants to understand that reactivation of latent TB remains a threat and that coming to the UK does not mean escaping TB. In addition, efforts must be directed to tackling the deep-seated stigma about the illness and, as part of wide health systems efforts, increase levels of GP registration.
PHE and NHS England’s implementation of the Collaborative Tuberculosis Strategy for England, 2015-2020 supported by £10 million in funding will have contributed to the steady decline in TB numbers and rates. Strategic aims were to achieve a year-on-year decrease in the rate of TB and reduce health inequalities. Its ultimate goal to eliminate TB still remains an ambitious one in spite of steady improvement.1
On a practical level, the NHS and PHE strengthened the coordination and oversight of all aspects of local TB control through the establishment of seven regional TB control boards. Other steps included launching an evidence-based service specification and clinical policy outlining what a model TB Service would look like. Additional resources were used to address specific gaps, for example to establish systematic latent TB testing and treatment of migrants.
There are also ten recommended evidence-based ‘areas for action’ and leading the list are: improve access to services and ensure early diagnosis; provide universal access to high quality diagnostics and improve treatment and care services for TB patients. So far all signs point to it working, but there is no complacency.
Yet figures alone are unpersuasive. It is clear we are on the road to, but still far from approaching the elimination of TB in England.
Among the key factors to eliminating TB in low incidence countries according to WHO include addressing social factors related to TB—a giant Pandora box requiring many political, health and social arms of society to work in tandem.
A Thorax Journal editorial warned that current policy must continue as “the future trajectory of TB incidence is uncertain and maintenance of the current favourable trends will require strict adherence to the measures undertaken lately.”4
PHE agrees writing that achieving the End TB pre-elimination goal of 1.0 per 100,000 population by 2035 “will be difficult”.
Mike Mandelbaum, chief executive of TB Alert, puts the pleasing reduction in TB incidence in the UK and the End TB goal in context and said: “Elimination by 2035 is a challenging target, but one the world should aspire to achieve. TB knows no borders, so the UK acting by itself cannot meet the target.”
The prospect then of ending TB in the UK must be viewed in a global context where travel is easy and therefore as studies suggest progress anywhere is predicated on success in care and control everywhere.
Claire Hunte, Medical journalist and formerly of International Union against Tuberculosis and Lung disease
Conflict of interest: none declared
2. World Health Organization. http://www.who.int/tb/en/
3. TB Alert. https://www.tbalert.org/about-tb/statistics-a-targets/uk-stats-and-targets/ (accessed 20/10/18)
4. https://thorax.bmj.com/content/thoraxjnl/early/2018/04/19/thoraxjnl-2018-211537.full.pdf (accessed 20/10/18)