Tuberculosis Annual Report for Scotland
2021 Tuberculosis Annual Report for Scotland

About this release​​​​​

This release by Public Health Scotland (PHS) presents national surveillance of tuberculosis and provides information on the numbers, distribution, and characteristics of cases, drug resistance patterns, and treatment outcomes. It supports the early identification and treatment of cases and enables the identification of high-risk populations. The Enhanced Surveillance of Mycobacterial Infections (ESMI) system was introduced in Scotland in 2000. Tuberculosis cases are identified by NHS Boards and notified to PHS. All 14 NHS boards contribute clinical, laboratory and epidemiological data to ESMI in three parts; on detection and notification of a case, when bacteriological results are known (at around 3 months) and at treatment completion (usually 12 months post notification). This report describes tuberculosis in Scotland through 2021, including treatment outcomes of cases first reported in 2020 (12-month outcomes) and 2019 (24-month outcomes). Please note that data in this report are provisional and may be subject to change as data continues to be received.

Main points

• In 2021, 225 tuberculosis cases (4.1 cases per 100,000 population) were reported to PHS. This represents a 4.9% increase in annual incidence compared to 2020 when there were 3.9 cases per 100,000 population (214 cases) and follows ten consecutive annual decreases in incidence since 2010. The cause of this increase requires further investigation.
• World Health Organization’s “End TB Strategy” set a target to reduce TB incidence by 20% between 2015 and 2020. Scotland has exceeded this by achieving a 34.3% reduction in incidence during this time.
• Tuberculosis incidence was highest among males aged 35 to 44 years (10.3 cases per 100,000 population) and males aged 25 to 34 years (9.3 cases per 100,000 population).
• In 2021, as in recent years, 72.4% of tuberculosis cases in Scotland, where place of birth was known, were born outside of the UK. Tuberculosis incidence in individuals born outside of the UK was almost 25 times higher than in individuals born in the UK. The most reported risk factor was being a refugee or asylum seeker (13%).
• In non-UK born tuberculosis cases, 86.4% were diagnosed two or more years after arriving in the UK. While it is not fully understood why individuals develop TB more than two years following entry to the UK, this could be related to either reactivation of latent infection following entry to the UK, infection once within the UK, or frequent travel abroad.
• The impact of deprivation is evident with 32% of cases reported in 2021 being resident in the most deprived Scottish Index of Multiple Deprivation (SIMD) quintile compared to 10.4% of cases in the least deprived quintile.
• Scotland has observed a further reduction in the proportion of cases that have pulmonary disease and is now at its lowest (51.1%) since reporting began in 2000. This is a positive development, as pulmonary cases pose a higher risk of transmission to others. The proportion of pulmonary cases confirmed by culture decreased to 83.5% in 2021 from 87.0% in 2020 but remains above the ECDC target of 80%. The proportion of pulmonary tuberculosis cases with a positive sputum result has decreased to 60.3% in 2021 from 63.2% in 2020 still well below the European target of 73%. This underscores the importance of prompt detection and treatment.
• Of the cases of TB reported in 2020, 74.3% successfully completed treatment compared to the ECDC recommendation that 85% of cases complete treatment within 12 months. This is an area where further work to understand any obstacles or barriers to treatment being completed may be needed.
• Mortality for reported cases of TB in Scotland is higher than that reported in England and some other European countries. In 2020, 25 cases (11.7%) were reported to have died before completion of treatment compared to 4.2% in England and a mean of 6.7% in other European countries. While no higher than previous years it is an area that requires attention.
• There were no multi-drug (MDR-TB) resistant isolates detected in 2021.

Further information

The next release of this publication will be November 2023.