Research and analysis

TB in children: incidence, epidemiology and microbiology in England, 2021

Updated 3 August 2023

Applies to England

About this report

Report series

This is the third in a series of 7 tuberculosis (TB) reports, previously published as a single report titled TB in England. Most health protection functions are devolved to the other UK nations’ public health teams in the UK, so this report only covers TB notifications and data from England.

This is the first year they have been published as a series of smaller reports and each will describe different aspects of TB incidence, treatment and prevention in England:

1. TB incidence and epidemiology in England, 2021
2. TB diagnosis, microbiology and drug resistance in England, 2021
3. TB in children: incidence, epidemiology and microbiology in England, 2021
4. TB treatment in England, 2021
5. TB treatment outcomes in England, 2021
6. TB prevention in England, 2021
7. TB in children: treatment and prevention in England, 2021

Report format

Information on how this series of reports fits within the TB action plan for England, 2021 to 2026, jointly published with National Health Service (NHS) England, along with a list of important monitoring indicators for the report series, can be found in TB incidence and epidemiology in England. There are no high-level indicators to report relating to TB in children.

Main messages

In 2021:

• the number and TB notification rate in children in England was the lowest since enhanced surveillance began in 2000
• more children notified with TB were born in the UK compared with adults (57.8% in children versus 21.8% in adults)
• the overall number and rate of TB notifications in children declined but TB notification rates increased in children born outside of the UK by 19% in 2021 compared with 2020
• there is significant variation in TB notification rates by ethnicity in UK-born children, with rates highest in ethnic groups other than white

Note: For reporting of TB, children are defined as aged under 15 years. Unless specified otherwise, adults are defined as those aged 15 years or over.

Executive summary

TB is an infectious disease, caused by bacteria of the Mycobacterium tuberculosis complex. It is predominantly spread by the respiratory route; people with infection in their lungs breathe out infectious bacteria in aerosols, which may then be inhaled by others.

Children are particularly vulnerable to TB, especially those aged under 5 years, who are at greatest risk of developing severe TB disease. Older children aged 15 years or over have a similar TB risk and clinical presentation to adults (aged 18 years or over). For the purpose of TB reporting, children are defined as those aged under than 15 years. This is in line with data reported to the World Health Organization (WHO). However, this will not capture the total work of paediatric TB services in England as they provide care up to age 16 years.

Globally, an estimated 1.2 million children fell ill with TB in 2021. TB disease is becoming much less common in children in England, with numbers and rates having trended downwards since 2012, except for a small rise in 2019. The highest numbers and rates since enhanced surveillance began in 2000 were in 2007, when there were 458 children notified with TB in England, at a rate of 5.0 per 100,000 children.

In 2021, there were 129 children notified with TB in England, with a rate of 1.3 per 100,000. This was a decline of 70% in numbers and 74% in rate since the peak in 2007 and the lowest recorded during the years of enhanced surveillance.

The highest numbers of children with TB in 2021 were in London (36 out of 129, 27.9%), followed by the West Midlands (23 out of 129, 17.8%). This reflects the geographical distribution of notifications for all age groups, where these 2 regions have the highest numbers and rates of TB.

In contrast with the pattern for adults, the majority of children with TB in 2021 were born in the UK (57.8% of children) compared with 22.9% for all age groups. However, this proportion has been declining since 2016 (79.2% of children with TB in 2016 were born in the UK).

Numbers of UK-born children with TB are highest in those who self-reported as being from the white or black African ethnic groups at 16 children each. This is a rate of 0.2 per 100,000 in the white ethnic group and 4.8 per 100,000 in the black African group. However, the rates are highest in those from the black-other ethnic group (3 children, a rate 9.0 per 100,000).

Although TB notification numbers and rates have been declining overall, rates in children born outside the UK are 10 times higher than for UK-born children. This increased in 2021 where it was at 54 children (8.2 per 100,000) compared with 2020 when it was at 46 children (6.9 per 100,000).

Most TB disease, and the highest rates, in both UK-born and non-UK-born children from 2000 to 2021 are in the 0 to 1 years and 14 to under 15 years age groups.

Severe TB disease (meningitis, cryptic, disseminated or miliary TB) affected 8.5 % of children with TB disease in 2021, and 10.3% in the 0 to 4 years age group. This is in contrast with 6.6% in those aged 15 years or over.

It is harder to obtain samples from children to confirm the diagnosis of TB by culture of the bacteria. This is reflected by much lower culture confirmation rates in children (33% in 2021, compared with 60.8% in all age groups). It can be harder to obtain sputum samples from young children as they do not always have a productive cough. Obtaining clinical samples from children can require invasive procedures which may not be considered necessary to confirm the diagnosis of TB. As such, fewer children will have samples for culture confirmation and will be treated empirically (as is in line with British Association for Paediatric Tuberculosis clinical guidance).

Culture is needed to provide information on drug susceptibility of TB, so information on this is sparser in children than in adults. In 2021, the proportion of children whose TB was confirmed on culture and had rifampicin resistant or multi drug resistant TB (RR or MDR TB) was higher at 9.3% (95% CI 2.6% to 22.1%) than in those aged more than 15 years at 1.8% (95% CI 1.3% to 2.4%).

The epidemiology, care pathways and management of children with suspected and with actual TB infection and disease, are distinct from those for adults, so data for children are presented separately in this report.

Children are identified as a specific population group requiring actions in the joint UKHSA and NHS England (NHSE) collaborative action plan 2021 to 2026, but there are no high-level indicators to report relating to TB in children.

TB notification numbers, notification rates and geographical distribution

Table 1 of the TB in children: Incidence, epidemiology and microbiology in England dataset shows the numbers and rates of TB notifications in children from 2000 to 2021 for all children and by country of birth (UK and non-UK-born).

In 2021, 129 children (aged less than 15 years) were notified with TB in England; a rate of 1.3 per 100,000 (95% confidence interval (CI) 1.1 to 1.6). This was a fall of 13% in both number and rate compared with 2020, when the rate was 1.5 per 100,000 (95% CI 1.2 to 1.7). This continues the year-on-year decline in numbers and rates observed since 2013, with the exception of 2019 (Figure 1 and Table 1 of the TB in children: Incidence, epidemiology and microbiology in England dataset). The rate and number of notifications in children in 2021 are the lowest recorded in England between 2000 and 2021.

Figure 1. The overall number and rate of TB notifications in children aged less than 15 years, England, 2000 to 2021

Distribution of TB in children by UKHSA centre

Numbers of children with TB by UKHSA centre are too small to calculate rates with a sufficient degree of confidence. Numbers of children with TB varies by UKHSA centre, with numbers largely reflecting the regional patterns for all TB notifications (Table 2 of the TB in children: Incidence, epidemiology and microbiology in England dataset). The highest number and proportion of children with TB was in London at 36 out of 129 children or 27.9%. This is followed by the West Midlands at 23 out of 129 children or 17.8%. The lowest numbers and proportions were in the East Midlands (4 out of 129 children, 3.1%) and North East (6 out of 129 children, 4.7%).

As numbers of children with TB decrease, specialist care may need to be delivered through regional networks, especially in areas with the lowest incidence.

Demographic characteristics of children with TB in England

TB in children by country of birth and ethnicity

In 2021, over half of children notified with TB who had a known country of birth were born in the UK at 74 out of 128 children or 57.8%. This proportion declined in 2021 compared with 2020 when it was at 67.8% and has continued to decline since a peak in 2016 (72.9%) (Table 1 of the TB in children: Incidence, epidemiology and microbiology in England dataset).

Figure 2 shows the numbers and TB notification rates for children born in the UK (Figure 2a) and outside of the UK (Figure 2b). In 2021, the TB notification rate in UK-born children fell to 0.8 per 100,000 (95% CI 0.6 to 1.0). This is the first time that the rate has fallen below 1.0 per 100,000 (Table 1 of the TB in children: Incidence, epidemiology and microbiology in England dataset).

In 2021, the rate of TB notification in children born outside the UK was 8.2 per 100,000 (95% CI 6.1 to 10.7). This is an increase of 19% compared with 2020 (6.9 per 100,000, 95% CI 5.1 to 9.3). The rate of TB notification in non-UK-born children was 10 times higher than in children born in the UK.

Figure 2a. Numbers and TB notification rates in UK-born children under 15 years, England, 2000 to 2021

Figure 2b. Numbers and TB notification rates in non-UK-born children under 15 years, England, 2000 to 2021

Table 3 of the TB in children: Incidence, epidemiology and microbiology in England dataset shows the numbers and TB notification rates for children by place of birth (UK and non-UK-born) by reported ethnicity. Among children born in the UK, the highest numbers of children notified were in the white and black African ethnic groups (16 children each). However, the rates were highest for the ethnic group classified as black other (9.0 per 100,000, 95% CI 1.9 to 26.4).

Among children born outside the UK, the highest numbers and rates of children notified with TB were reported as having Indian (15 children, 18.6 per 100,000, 95% CI 10.4 to 30.7) and Pakistani ethnicity (9 children, 13.1 per 100,000, 95% CI 6.0 to 24.9). These rates were much higher than in UK-born children with Indian and Pakistani ethnicity.

India, Pakistan and Afghanistan were the most frequent countries of birth among children diagnosed with TB if excluding the UK, with 8.6% born in India, and 5.5% born in Pakistan and Afghanistan each (Table 1). The other most frequent countries of birth all had fewer than 5 children.

Table 1. Most frequent countries of birth for children with TB, England, 2021

Country of birth	Number of children	Proportion of children (%)
United Kingdom	74	57.8
India	11	8.6
Pakistan	7	5.5
Afghanistan	7	5.5

Note: Place of birth was unknown for 1 child.

Age and sex distribution differ between UK-born and non-UK-born children

In 2021, notifications of TB in children were equally divided between males (65 children, 50.4%) and females (64 children, 49.6%). However, in non-UK-born children, the proportion of females was slightly higher at 57.4% or 31 out of 54 children with known country of birth (Figure 3a and 3b).

Overall, numbers of TB notifications were highest in the 10 to 14 years age group at 70 children (54.7% of total children) and lowest in children aged 5 to 9 years at 23 children (18.0%). However, whilst the proportion of notifications per age group was fairly evenly distributed among UK-born children with TB, a much greater proportion of non-UK-born children with TB were in the 10 to 14 years age group at 42 children (77.8%) compared with the other age groups (Figures 3a and 3b).

Figure 3a. Proportion of TB notifications in UK-born children by sex and age group, England, 2021

Figure 3b. Proportion of TB notifications in non-UK-born children by sex and age group, England, 2021

Age-specific rates for data aggregated for years 2000 (when enhanced surveillance began) to 2021 are shown in Figure 4. Rates for UK-born, and non-UK-born children are highest in those aged 1 to 2 years and 14 to 15 years (Table 4 of the TB in children: Incidence, epidemiology and microbiology in England dataset). In non-UK-born children aged 14 to 15 years, the rate is approximately 15 times greater than the same age in UK-born children.

Figure 4. Numbers and rates by age for UK-born and non-UK-born children, 2021

Clinical characteristics

Site of disease

Information on the site of disease is collected for individuals as it has implications for diagnosis and treatment.

Table 2 shows the site and severity of disease in children in 2021. Site of disease was known for all children with TB in 2021. Over half (54.3%) of children had pulmonary disease. The proportion of children with pulmonary disease differed by age group, it was highest in the 0 to 4 years group (72.2%) and lowest in the 10 to 14 years group (44.3%).

In 2021, there were 11 children (8.5%) classified as having severe TB disease (TB meningitis, cryptic disseminated or miliary TB). This was a higher proportion than in 2020 at 3.4% (6 out of 149) and 2019 at 7.8% (13 out of 166).

The proportion of children with severe disease was higher than in adults which was at 6.6% (TB incidence and epidemiology in England). Additionally, the proportion of children classified as having severe disease was slightly higher in those aged 0 to 4 years at 10.3%, compared with 8.5% for all children.

Table 2. Site and severity of disease in children with TB, England, 2021

Clinical characteristic	0 to 4 years	5 to 9 years	10 to 14 years	Total
All disease sites	36 (27.9%)	23 (17.8%)	70 (54.3%)	129 (100%)
Pulmonary	26 (72.2%)	13 (56.5%)	31 (44.3%)	70 (54.3%)
Extra-pulmonary	10 (27.8%)	10 (43.5%)	39 (55.7%)	59 (45.7%)
Severe TB	4 (10.3%)	2 (8.7%)	5 (10.0%)	11 (8.5%)
Lymph nodes only	6 (16.7%)	6 (26.1%)	24 (34.3%)	36 (27.9%)
Other	2 (5.6%)	2 (8.7%)	12 (17.1%)	16 (12.4%)

Note: 1. Severe disease comprises TB meningitis, miliary or cryptic disseminated.
2. Children with pulmonary disease may have disease in other sites as well and therefore numbers may add up to more than the number of total children.

Culture confirmation

Overall, in 2021, 33.3% (43 out of 129 individuals) of TB disease in children was confirmed by culture. Of those with pulmonary disease, 40% (28 out of 70) were culture confirmed compared with 25.4% (15 out of 59) of children who had non- pulmonary disease (Table 5 of the TB in children: Incidence, epidemiology and microbiology in England dataset).

Culture confirmation proportions for children differed by UKHSA centre, with the highest confirmation proportion in the East Midlands (3 out of 4 children culture positive, 75%) and lowest in the North East (1 out of 6, 16.7%). In both the South East (4 out of 8) and Yorkshire and the Humber (5 out of 10), culture confirmation proportions were 50% (Table 6 of the TB in children: Incidence, epidemiology and microbiology in England dataset).

As numbers are small in most regions, there can be significant fluctuation in culture confirmation proportions from year to year.

Drug resistance

Susceptibility of the TB bacteria to anti-tuberculous agents is reported for all culture-confirmed individuals with TB. In 2021 of the 43 children with culture confirmed TB:

• none were isoniazid resistant without MDR TB at diagnosis
• 4 (9.3%) were MDR or rifampicin resistant (RR) TB
• 1 (2.3%) was pre-extensively drug resistant (pre-XDR) at diagnosis

Although there were only 4 children aged less than 15 years with RR or MDR TB at diagnosis, the percentage with RR or MDR TB was higher at 9.3% (95% CI 2.6% to 22.1%) of culture confirmed children compared with 1.8% (95% CI 1.3% to 2.4%) for those aged 15 years or older and compared with all people with TB at 1.9% (TB incidence and epidemiology in England). A total of 7 children were treated for MDR TB or pre-XDR (5.4% of the children with TB in 2021).

Rates of TB notification in children as a proxy for recent transmission

TB in children born in the UK indicates likely recent transmission as children have a limited time during which they could have become infected, and, if going to develop active infection, this is usually within 12 months. Therefore, the rate of TB notification in children (aged under 15 years) born in the UK can be used as a proxy for recent transmission within England.

Figure 5 shows the rate for UK-born children only over the period 2000 to 2021 (Table 1 of the TB in children: Incidence, epidemiology and microbiology in England dataset). There has been a year-on-year reduction in the rate of TB notification in children from 2016 (1.8 per 100,000, 95% CI 1.5 to 2.1) to 2021 (0.8 per 100,000, 95% CI 0.6 to 1.0). Overall, this is a decrease of 55.6% in a 6-year time period.

Figure 5. The overall rate of TB notification in children (less than 15 years) born in the UK, England, 2000 to 2021

Conclusions and recommendations

TB notification numbers and rates continue to decline in UK-born and non-UK-born children. However, there remain groups with much higher risk of TB and the focus on TB detection and care in children needs to be maintained to reduce the incidence in these groups.

Children are more likely to have severe disease than adults.

Children are less likely than adults to have their diagnosis confirmed by culture. There is regional variation in culture confirmation rates, for which the reasons are unclear.

Care for children with TB should remain a focus, with the elements of the collaborative action plan specifically relating to children being included in local planning and evaluation.

In line with TB action plan 2021 to 2026 priority areas, local services and areas should work to ensure that:

1. unaccompanied asylum-seeking children should be targeted for screening for active and latent TB infection (action plan priority 2.4)

2. new guidance from the British Association for Paediatric Tuberculosis in 2023 should be used to promote best practice and improve proportion of diagnoses in children confirmed by culture (action plan priority 3.3)

3. TB pathways are in place in all areas for children, which include access to TB advice and support from a specialist TB Service through a ‘hub and spoke’, ‘virtual clinic’ or shared care model (action plan priority 4.1.3)

Methodology and definitions

Details of the methodology and definitions are described in TB incidence and epidemiology in England, 2021 and TB diagnosis, microbiology and drug resistance in England, 2021.

Glossary

Please see glossaries in TB incidence and epidemiology in England, 2021 and TB diagnosis, microbiology and drug resistance in England, 2021.