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National Collaborating Centre for Chronic Conditions (UK); Centre for Clinical Practice at NICE (UK). Tuberculosis: Clinical Diagnosis and Management of Tuberculosis, and Measures for Its Prevention and Control. London: National Institute for Health and Clinical Excellence (UK); 2011 Mar. (NICE Clinical Guidelines, No. 117.)

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Tuberculosis: Clinical Diagnosis and Management of Tuberculosis, and Measures for Its Prevention and Control.

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Appendix GSummary of Healthcare Needs Analysis - 2006

The epidemiology of tuberculosis in England and Wales (2004)

Acknowledgements

The following people have contributed to this epidemiology review by providing raw data, references to relevant research, or comments on earlier drafts.

Mrs Delphine Antoine - Tuberculosis surveillance co-ordinator, Health Protection Agency Centre for infections, London

Dr John Hayward - former Director of Public Health, Newham Primary Care Trust, London

Dr Jane Jones - Consultant Epidemiologist, Health Protection Agency Centre for infections, Communicable Disease Surveillance Centre, London

Dr Helen Maguire - Regional Epidemiologist, Health Protection Agency, London

Dr Jonathan Mant - Senior Lecturer, University of Birmingham

Professor Peter Ormerod - Consultant Physician, Blackburn Royal Infirmary, Blackburn

Ms Sally Taylor - Trainee Information Analyst, Patient Data Information Team, Health Solutions Wales

Dr John M Watson - Consultant Epidemiologist and Head of Respiratory Diseases, Health Protection Agency Centre for infections, London

Context

This summary overview of the epidemiology of TB disease in England and Wales was originally presented to the GDG in April 2004 both as background and as an aid to assist in the group's formulation of practical and relevant guideline recommendations. It is not therefore based on the most up to date epidemiological data available at the time of publication of this guideline, but is intended only as a record of what was considered by the GDG in the context of the guideline development process.

Introduction

Tuberculosis (TB) remains a major international public health concern, with the global incidence rate increasing at approximately 0.4% per year, but much faster in sub-Saharan Africa and in countries of the former Soviet Union. The 183 countries reporting to WHO in 2001 notified 3.8 million TB cases (62 per 100 000 population), of which 1.6 million (42%) were sputum smear-positive. The African (21%), SouthEast Asian (37%), and Western Pacific Regions (22%) accounted for 80% of all notified cases and similar proportions of sputum smear-positive cases. ({WHO Global Tuberculosis Control Report, 2003})

In the context of the WHO European region, which includes 51 countries, 385 810 cases of TB were notified in 2000, with an overall incidence of 44 per 100 000 population ({Euro TB, 2003}). In the 14 Western European countries the incidence was 12 per 100 000, with the United Kingdom being only one of four countries in this region reporting an increase (less than 2% annually) in TB notification rates between 1995 and 2000 ({Euro TB, 2003}). Despite the relatively low incidence for the UK in 2000 of 11.4 per 100 000 population, the slight annual increase in TB notifications since 1995 is a cause for concern.

Tuberculosis disease and death rates in England and Wales

In England and Wales all forms of TB disease are compulsorily notifiable by the physician making or suspecting the diagnosis under the Public Health (Control of Disease) Act 1984. It first became a statutory requirement to notify suspected cases of TB in 1913, and the 1921 Public Health Tuberculosis Act expanded this legal requirement throughout England and Wales. This statutory notification of infectious diseases system (NOIDS) continues to play a role in the surveillance of TB. (Source: Health Protection Agency - CDSC - TB section).

However, Enhanced Tuberculosis Surveillance, a system established in 1999 for the collection of more detailed information on the occurrence of tuberculosis in England and Wales, recently reported higher case numbers of TB disease compared to NOIDS. Enhanced TB Surveillance provides an annual corrected analysis of TB case reports by age, sex, ethnic group, country of birth, site of disease and NHS region, and from 2002, treatment outcome. This system has reported a continued rise in TB disease cases from 1999 to 2002, and as it involves several measures to validate reports, it is likely better to reflect the true incidence of TB. For this reason caution is advised in interpreting recent NOIDS data. (CDR Weekly vol. 14 no. 30, 2004).

It should be noted that neither the NOIDS nor Enhanced TB Surveillance systems collect information on persons with latent TB infection. The data in this document refer only to cases of active TB disease, and not to latent infection.

Between 1913 and 1987 the TB notification rate in England and Wales fell from over 320 per 100 000 to 10.1 cases per 100 000 population. However, the period 1987 to 2002 has seen a trend towards increasing rates (10.1 to 12.9 per 100 000).

The TB death rate declined overall from 1.14 to 0.73 per 100 000 population in the 20-year period 1982 to 2002. Most of this decline occurred in those aged 45–64 and 65 plus (reductions of 1.12 and 1.44 per 100 000 population respectively). However, over the same period there was a slight increase in the death rates for younger age groups (see Table i below).

Table i. Increase in TB death rates over the 20-year period 1982–2002.

Table i

Increase in TB death rates over the 20-year period 1982–2002.

TB cases by region

Enhanced TB Surveillance data on regional variation in TB disease prevalence indicate that London had the highest rates in England and Wales for the period 1999–2001, and experienced the sharpest increase in TB disease rates over this time from 32.8 to 37.8 per 100 000 (an increase of 5 per 100 000).

TB Notification data for 2002 show great cross-sectional variation in the TB disease rates in London boroughs varying from 89 per 100 000 in Newham to 3 per 100 000 in Bromley. Longitudinal trends have also varied between different London boroughs, for example in the 20-year period from 1982 to 2002, when rates in Hackney increased from 33 to 65 per 100 000, while in Hammersmith and Fulham they fell from 35 to 6 per 100 000. (Source: Health Protection Agency London, Notifications of Tuberculosis per London borough, 1982 – 2003)

Rising notification rates within boroughs may reflect changing demographic characteristics in populations, which increase the likelihood of TB disease occurring, rather than an inability of local health services to deal with a static public health problem.

Table ii below shows the regional variation in TB disease rates for England and Wales outside of London for 2001. While other cities in England and Wales apart from London may have high rates of TB disease relative to their surrounding suburban and rural areas, HPA data on TB rates in cities other than London were unavailable when the GDG considered these data in 2004, due to potential limitations in the datasets and calculation procedures used.

Table ii. TB disease rates by region in England and Wales 2001.

Table ii

TB disease rates by region in England and Wales 2001.

TB case rates and ethnic group

Enhanced TB Surveillance data for 2001 show that nationally, the Black African ethnic group had the highest TB disease rate followed by the Pakistani and Indian ethnic groups (see Table iii below).

Table iii. TB disease case rates by ethnicity, 2001.

Table iii

TB disease case rates by ethnicity, 2001.

It is possible that regions with larger populations of ethnic minorities may have higher overall numbers of TB cases in comparison to regions with smaller ethnic minority populations. The following two sections focus on data relevant to this issue.

TB cases by ethnicity and region

In 2001 Whites accounted for more than half of the TB disease caseload in Wales, the South West, North East, and East Midlands. In London, the West Midlands, the North West, South East, and Yorkshire and Humberside other ethnic minority groups contributed the major proportion of TB disease cases (Table iv).

Table iv. TB cases (proportion) reported by region and ethnic group, 2001.

Table iv

TB cases (proportion) reported by region and ethnic group, 2001.

TB cases by ethnicity and country of origin

It would be an oversimplification to attribute the high TB case rates in London (37.8 per 100 000) solely to the presence of greater concentrations of ethnic minority groups in the city. Data for the period 1998 to 2001 found that TB disease rates were substantially higher in people born abroad compared to those born in the UK (see table v below).

Table v. Trend in TB disease case rates in people born in the UK and abroad.

Table v

Trend in TB disease case rates in people born in the UK and abroad.

Foreign-born TB cases accounted for 63% of the national caseload and people born abroad were 15 times more likely to have TB disease compared to those born in the UK. (Source: Health Protection Agency)

In terms of ethnicity, TB disease rates for people born in the UK were much lower for all groups, compared to the rates for those born abroad (Table vi below).

Table vi. Trend in TB disease case rates by ethnicity in people born in the UK and abroad.

Table vi

Trend in TB disease case rates by ethnicity in people born in the UK and abroad.

There was also considerable variation between the different ethnic groups for time from entry into the UK until development of TB disease (N=5589 cases; Table vii below), with the Black African ethnic group tending towards shorter time to active TB.

Table vii. Proportion of TB cases reported in the foreign born population by ethnic group, and by time since entry into the UK, 1998 – 2001.

Table vii

Proportion of TB cases reported in the foreign born population by ethnic group, and by time since entry into the UK, 1998 – 2001.

Foreign-born people resident in the UK for less than one year contribute proportionally fewer cases of TB disease to the annual data than all foreign-born residents settled in the country for at least 10 years. However, this should not obscure the fact that the rates of TB disease in new immigrants are much higher than among foreign-born residents living in the UK for at least 10 years.

There is wide regional variation in the ratio of foreign-born TB cases to cases born in the UK. Table viii below shows the opposite ends of the spectrum in this regard for 2001.

Table viii. Foreign and local born TB cases in London and Wales, 2001.

Table viii

Foreign and local born TB cases in London and Wales, 2001.

Wales, the South West and the North East had the highest proportions of local-born TB cases, while London, the South East, Eastern and North Western parts of England had the highest proportions of foreign-born TB cases. (Source: Health Protection Agency – CDSC - TB section-2001- Enhanced TB Surveillance).

Ethnicity, place of birth, and length of residence in the UK all appear to be important factors in accounting for regional variation in rates of TB disease in England and Wales. In the following section, the contribution of age and sex variables is explored.

TB cases by sex and age

The 1998 TB Survey and Enhanced TB Surveillance data from 1999 to 2001 provided national TB case rates broken down by sex and age. In 2001, men aged 25–34 had the highest TB disease rates (see Table ix). Women had somewhat lower TB disease rates, with those aged 25–34 having the highest.

Table ix. TB disease rates by sex and age group, 2001.

Table ix

TB disease rates by sex and age group, 2001.

Longitudinal data for the 1998–2001 period (Table x below) indicate that rates for younger males and females (15–24; 25–34) appear to be increasing, compared to older age groups.

Table x. TB disease case rates for males and females aged 15–34, 1998–2001.

Table x

TB disease case rates for males and females aged 15–34, 1998–2001.

Regional variations in TB cases by age and sex

There is also regional variation in the distribution of TB disease cases according to age group. Enhanced Surveillance data for 2001 showed the highest proportions of TB cases outside of London and Eastern England occurred in those aged 45–64 and 65 plus (Table xi below). In Eastern England and London the highest proportions of TB cases occurred in those aged 25–34.

Table xi. Proportion of TB cases reported by age group and region, 2001.

Table xi

Proportion of TB cases reported by age group and region, 2001.

TB disease can either arise from recent exposure to and infection with Mycobacterium tuberculosis, or from the reactivation of dormant tubercule bacilli years or decades after initial infection ({Elender et al., 1998}, p.674). In England and Wales, older people who lived through a period of high TB incidence are more likely to have been infected, and reactivation of bacilli in this population may account for a large proportion of TB cases occurring in the age 45–64 and 65 plus age groups. In contrast, TB cases in younger age groups are more likely to be due to newly acquired external infection ({Elender et al, 1998}, p.674).

The 1998 TB survey and enhanced TB Surveillance data for 1999–2001 show that the median age of foreign-born UK TB cases is consistently younger (age 36 in 1998; 35 in 2001) compared to the median age of local-born UK TB cases (age 50 in 1998; 44 in 2001). (Source: Health Protection Agency – CDSC - TB section - National TB Survey 1998, 1999, 2000 and 2001 Enhanced TB Surveillance).

This suggests that the higher proportion of foreign-born TB disease cases in London and Eastern England contributed to the high proportion of cases aged 25–34 in these areas. In other areas of England and Wales, TB disease in older age groups is more likely to be due to reactivation of prior long-term infection. It is also possible that different age groups have different risks for TB disease when analysed according to ethnicity. However, regional TB disease data broken down according to ethnicity and age was not available from the HPA at the time this document was written, since the denominator data used for ethnic groups is sourced from the Labour Force Survey, and this data is less reliable at the regional level.

TB cases and socio-economic deprivation

Aside from ethnicity, recent immigration, duration of residence in the UK, and age, other factors such as poor housing and overcrowded conditions may contribute to the increasing incidence of TB in the UK. A national survey of TB in the UK conducted by {Rose et al. (2001)} did not collect information on the socio-economic and housing status of the respondents, and so was unable to provide data on the effect of poverty on the occurrence of TB and its geographical variation in England and Wales. Enhanced TB surveillance surveys conducted from 1999 to 2001 by CDSC also did not collect information on the socio-economic status of TB disease cases.

One study ({Bhatti et al., 1995}) attempted to link TB notification data with socioeconomic deprivation on a national basis. The study used the Jarman Index to rank the 403 local authority districts in England and Wales in terms of socio-economic deprivation and compared local authority data with TB notifications. The study found that both overcrowding and ethnic minority status were strongly related to risk of TB disease (36% of cases occurred in the 10th of the population with the highest overcrowding index, while 33% of cases occurred in the 10th of the population with the highest number of ethnic minority residents).

However, the validity of the findings were undermined by the high correlation between the overcrowding and the ethnic minority factors (r=0.85). It is likely that ethnicity was an important confounder of the relation between TB and social deprivation ({Hayward et al., 1995}) in this study, and the real contribution of overcrowding to TB disease remains unclear. The Jarman index may have been inappropriate, since it included ethnicity as one of its other defining criteria, which was also strongly correlated with TB incidence. Use of the Townsend Deprivation Index would have avoided this problem since it only includes overcrowding and not ethnic minority status as one of its four criteria.

A study conducted in London by the London Tuberculosis Nurses' Network found that 235/2010 (12%) of TB disease cases in the capital were homeless, including 79 (4%) currently living in homeless hostels or on the street and 156 (8%) living in temporary insecure accommodation such as bed and breakfast rooms or squats. An additional 112 TB patients (5.7%) had a history of street or hostel homeless. No national dataset on the proportion of TB disease cases currently homeless was available at the time of writing.

TB cases and previous TB diagnosis

Enhanced TB Surveillance 2001 provides regional information on previous TB diagnosis. Nationally, for cases where information was reported on this issue (19.5 % of the total TB cases for 2001 had no or incomplete information), 91.4 % had no previous TB diagnosis compared to 8.6 % who did. There was variation in these case proportions by region, with the South West of England reporting the highest percentage of previous TB diagnoses (13.5%) and the West Midlands reporting the lowest percentage (6.8%). London reported a low percentage of cases with previous TB diagnosis (7.4%). (Source: Health Protection Agency – CDSC – TB section – 2001 - Enhanced TB Surveillance).

In London increasing age and poor adherence were independently associated with previous tuberculosis, while the relationships between previous TB and homelessness, imprisonment, alcohol and drugs were found not to be significant after controlling for poor adherence (The London Tuberculosis Nurses Network - A Hayward, personal correspondence). No national data on the risk factors associated with a previous TB diagnosis were available at the time this document was drafted.

TB cases by site of disease

Enhanced TB Surveillance 2001 data included information on the site of TB disease. TB cases were classified as:

  • Pulmonary with or without additional extra-pulmonary disease, and
  • Only extra-pulmonary TB disease.

In England and Wales 55% of TB cases had pulmonary disease and 45% had only extra-pulmonary disease. Regionally there was some variation, with Wales having the highest (62%) and the West Midlands the lowest proportion of pulmonary cases (52.5%). The proportions for London were close to the national figures (56% pulmonary and 44% non-pulmonary). (Source: Health Protection Agency – CDSC – TB section – 2001 - Enhanced TB Surveillance)

TB cases and HIV co-infection

{Rose et al. (2002)} matched information from the 1993 and 1998 national TB survey databases with data from the HIV/AIDS database in order to identify cases of TB-HIV co-infection in England and Wales. In addition, the HPA collated data on 17 633 TB cases from the 1998 TB Survey and the 1999–2001 Enhanced TB Surveillance surveys and matched these with the HIV/AIDS patient database. TB disease and HIV co-infection was found in 479 (2.7%) TB cases. (Health Protection Agency – CDSC – TB section - Poster - Antoine, Delpech, Story, Forde, Mortimer, Evans, and Watson. Tuberculosis and HIV co-infection in England and Wales, 1998 to 2000.) Relevant data from these two sources is reported under the sub-headings below.

Age

In co-infected HIV/TB cases, 99.6% were aged between 15 and 64 years. No cases were found below the age of 15 and just two were over 64 years of age. The groups with the highest proportions of co-infection were aged 35–39 (7.3%), 30–34 (6.4%), and 40–44 (4.7%). (Sources: Health Protection Agency – CDSC – TB section, National TB Survey 1998, 1999, 2000 and 2001 Enhanced TB Surveillance; HIV/AIDS patients dataset).

Sex

Sixty-four percent of HIV-TB co-infected cases were males. (Health Protection Agency – CDSC – TB section - Poster - Antoine, Delpech, Story, Forde, Mortimer, Evans, and Watson. Tuberculosis and HIV co-infection in England and Wales, 1998 to 2000.)

Region

Sixty-five percent of all HIV/TB co-infected cases between 1998 and 2000 were found in London (Health Protection Agency – CDSC – TB section - Poster - Antoine, Delpech, Story, Forde, Mortimer, Evans, and Watson. Tuberculosis and HIV co-infection in England and Wales, 1998 to 2000.). {Rose et al (2002)} found that in 1993, 64% of all HIV/TB co-infected patients aged 16–54 were in London, and in 1998 this had increased to 77%. The London Tuberculosis Nurses Network study found that 188/2010 (9.6%) TB cases in London had confirmed HIV co-infection (although one third of patients were not tested).

Ethnicity

In London the proportion of HIV/TB co-infected patients of White ethnic origin increased from 5.2% to 9.8% between 1993 and 1998, while the proportion of Black African HIV/TB cases increased from 7.4 to 10% during the same five-year period ({Rose et al. 2002}, p.443).

Outside London between 1993 and 1998 there was an 18% rise in the number of HIV/TB co-infections, mostly in the White ethnic group, but by 1998 the proportion of co-infection cases in the White ethnic group was still only 2% versus 10% in Black African patients (Rose et al., 1998, p.443).

Place of birth

HPA 1998–2001 data indicate that the overall proportion of HIV/TB co-infection cases was higher in persons born abroad than in those born in the UK (3.9% vs. 2.8%). However, the contribution varied considerably between regions of the world (Table xii).

Table xii. HIV/TB cases in England and Wales born abroad.

Table xii

HIV/TB cases in England and Wales born abroad.

Site of disease

Sixty-seven percent of all HIV/TB co-infected cases had pulmonary TB disease. (Health Protection Agency – CDSC – TB section - Poster - Antoine, Delpech, Story, Forde, Mortimer, Evans, and Watson. Tuberculosis and HIV co-infection in England and Wales, 1998 to 2000.)

Risk factors for HIV-TB co-infection

On univariate analysis, HIV/TB co-infected cases were significantly more likely to be:

  • male
  • aged 30 to 49 years
  • born in Africa or Europe (except in the UK)
  • living in London
  • ill with pulmonary TB.

The results represent a minimum estimate of HIV/TB co-infection due to limitation in the matching process and probable under reporting of tuberculosis cases among people with HIV. (Sources: Health Protection Agency – CDSC – TB section - Poster - Antoine, Delpech, Story, Forde, Mortimer, Evans, and Watson. Tuberculosis and HIV co-infection in England and Wales, 1998 to 2000.).

TB cases and treatment outcomes

Information on treatment outcome of all TB cases reported in 2001 was collected from January 2002 in England, Wales, and Northern Ireland. The analysis of the first national results was performed on 5139 TB cases, representing 79% of all cases reported in 2001. The key socio-demographic variables of TB cases with and without outcome data were similar when compared (CDR Weekly 14 (1), 2004).

  • Almost 80% of TB cases with outcome data completed treatment at 12 months.
  • The treatment completion rate was significantly lower in pulmonary cases than in extra pulmonary cases (77% versus 84%, p<0.001).
  • Overall 8.3% of patients died, representing 39% of the 1106 cases failing to complete treatment at one year.
  • The proportion with treatment completion decreased in the older age groups (>80% in those aged under 60 years, and <70% in those aged 70 years and over, p<0.001) reflecting the contribution of death in older age.
  • Four percent of all cases were lost to follow-up and 4% were still on treatment.
  • The proportion of cases lost to follow-up in the 10 – 34 years age group was 6.3% versus 1.3% in those aged 0–9 years versus 2.5% in those aged 35 plus, p< 0.001.

Cure and completion rates were defined by recording death (from any cause) as non-completion, so these rates cannot be expected to reach 100%. (Source: Health Protection Agency – CDSC - TB section – 2001- Enhanced TB Surveillance). The data should be interpreted with caution, as outcome information was unavailable for 21% of TB cases reported in 2001 (CDR Weekly 14 (1), 2004).

In London, a multivariate analysis revealed that a history of homelessness, imprisonment, problem drug use, problem alcohol use, mental health problems, living alone and previous tuberculosis were independently associated with poor treatment adherence amongst TB patients (The London Tuberculosis Nurses Network).

TB cases and drug resistance

The proportion of drug resistant cases reported through Enhanced TB Surveillance for 2001 was derived from MycobNet information on initial isolates at the start of treatment. The proportion of TB isolates (N=4043) with some form of drug resistance was as follows:

  • Isoniazid resistance 7.84%,
  • Rifampicin resistance 1.7%
  • Multiple Drug Resistance (MDR) 1.24%

(Sources: Health Protection Agency – CDSC - TB section – 2001 - Enhanced TB Surveillance and MycobNet).

In England and Wales in the period between 1994 and 2001, isoniazid resistance increased by 2.04%, rifampicin resistance decreased slightly by 0.2%, and MDR-TB decreased by 0.26%. (Source: Health Protection Agency – CDSC – TB section – 2001 - Enhanced TB Surveillance and MycobNet).

Risk factors for drug-resistant TB

{Djuretic et al. (2002)} reported an analysis of MycobNet data that included 24,876 initial isolates of Mycobacterium Tuberculosis collected between 1993 and 1999.

The highest proportions of isoniazid resistance and MDR-TB were reported in the following groups (isoniazid-resistant %, MDR TB %):

  • Those aged 15–44 (7.6%, 1.5%)
  • Males (5.9%, 1.4%) compared to females (5.4%, 0.9%; MDR p<0.001).
  • Black African cases (10.1%; 2%) compared to Indian subcontinent (7.2%; 1.4%) versus White ethnic group cases (4.1%; 1.4%)
  • TB cases born abroad (9.1%, 2%) compared to UK born (4.2%, 1%; isoniazid p<0.001, MDR p<0.001)
  • London (7.6%, 1.7%) compared to rest of the UK (4.6%, 0.9%)
  • England (6%; 1.3%) compared to Wales (4.4%; 0.6%)
  • Pulmonary TB (MDR 1.5%) compared to non-pulmonary TB (MDR 0.8%; p<0.001).
  • Previous TB diagnosis (15.5%, 9.4%) compared to TB cases without previous diagnosis (5.7%, 0.8%) compared to cases with no available data (4.9%, 0.7%; isoniazid p<0.001, MDR p<0.001)
  • TB/HIV co-infection confirmed in 3.6% of all isolates collected between 1993 and 1999 (11.6%, 4.6%) compared to s cases with unknown and negative HIV status (5.5%, 1.1%; isoniazid resistance p<0.001, MDR p<0.001) ({Djuretic et al., 2002}, p.480).

In the context of London, a multivariate analysis found that history of imprisonment and previous tuberculosis were independently associated with drug resistance (isoniazid or MDR-TB; both p<0.001) in TB cases (The London Tuberculosis Nurses Network).

TB and NHS hospital resources

According to Hospital Episode Statistics (HES) data for England, TB disease accounted for 5666 finished hospital episodes for the year 2002 – 2003. This represented 0.04 % of all finished NHS hospital episodes for all diagnostic categories that year.

  • TB of the lungs and respiratory system accounted for 3779 hospital episodes (67% of all completed TB hospital episodes), and 38 833 hospital bed days (61% of all bed days for TB admissions).
  • Sixty-nine percent of TB patients were aged 15–59, with 10% aged 75 plus.
  • Male patients accounted for 57% of all finished TB episodes.
  • Mean length of stay in hospital was 18.1 days for TB compared to 7.9 days for all diagnostic categories.
  • Just 8% of all completed TB episodes were day cases (admitted and discharged on the same day) compared to 29% for all diagnostic categories.
  • The total number of bed days occupied by all TB patients was 63 347, or 0.12 % of all bed days for all primary diagnostic categories for that year.

(Source: Hospital Episode Statistics, England, 2002–03 http://www.doh.gov.uk/hes/tables/tb00202a.pdf)

In Wales, TB accounted for 153 finished episodes of hospital treatment in 2001–02, representing 0.02% of all completed hospital episodes during this period (Patient Episode Data Wales).

  • Lung and respiratory forms of TB accounted for 107 completed hospital episodes and 1199 bed days (57% of all TB bed days in Wales).
  • Sixty-six percent of TB admissions were male, with 57% of TB episodes completed by patients aged 15–59 and 20% by those aged 75 plus.
  • Six percent of all TB admissions were day cases with the remaining 94% requiring a stay of at least one night. For all diagnostic categories, the proportion of day cases was 18%.
  • Completed TB episodes amounted to 2120 bed days, or 0.05% of all hospital bed days for all diagnostic categories.

(Source: Health Solutions Wales - Patient Episode Data Wales (PEDW) 2001–2002 via personal communication).

BCG vaccination

Prior to intended immunisation with BCG, a tuberculin skin test is administered and only those who are found negative are immunized, although infants can be immunized without a skin test. In England in 2002–03, just over 413 000 persons were skin-tested of whom 33 000 (8%) were TST positive, including some due to previous immunisation. Just over 449 000 BCG vaccinations were administered, with Table xiii providing a breakdown of the data by relevant age group.

Table xiii. BCG vaccinations by age group in England, 2002–03.

Table xiii

BCG vaccinations by age group in England, 2002–03.

In Wales, 33 536 BCG vaccinations took place in 2002–2003, with Table xiv providing a breakdown of the data by relevant age group.

Table xiv. BCG vaccinations by age group in Wales, 2002–03.

Table xiv

BCG vaccinations by age group in Wales, 2002–03.

There was some evidence that BCG vaccination coverage varied in different regions of England and Wales. A survey conducted by {Joseph et al. (1992)} found that 15/169 health districts in England and Wales had discontinued routine school BCG vaccination by 1992, and 31/169 districts did not offer a neonatal BCG program. A total of 148 health districts (80%), including 14 of the 15 districts without a school BCG program, offered BCG to babies from ethnic minority groups, and 120 districts offered BCG vaccine to neonates of recent immigrants from high incidence countries ({Joseph et al., 1992}, p.496). There was no national dataset available at the time of drafting this document on regional variation of BCG vaccination coverage defined as that proportion of the local population of eligible candidates who receive BCG.

Conclusion

The rising incidence of TB in England and Wales since 1987 may be linked to a number of different socio-demographic factors. The major contributor on a regional level to this rising incidence is London, and yet within the capital there is a great degree of variation in TB rates within boroughs. Some boroughs have incidence rates below the national average of 12.9 per 100 000, while others have rates in excess of 80 per 100 000. Other cities in England and Wales may also be contributing to this rise in TB incidence, but at the time this document was written, the TB case rate data that existed for other specific cities was not considered reliable.

The concentration of ethnic groups, some of which include large numbers of people born abroad, may explain some of the local variation in TB rates both within London, and also between different regions in England and Wales. However, both country of birth, and length of residency in England and Wales appear to be important risk factors for TB disease. Unfortunately, there is an absence of robust national data on the impact of socio-economic deprivation on TB disease rates.

The HPA Centre for infections intends to begin collecting socio-economic data on TB cases in future, and this may facilitate a clearer understanding of the relative contributions of ethnicity, country of birth, length of residency and socio-economic deprivation to TB disease rates in England and Wales.

Age and sex are also important variables, since males have higher rates of TB disease than females, and TB rates are increasing more rapidly for those aged 15–24 and 25–34, particularly in London and the Eastern NHS region. Those aged 45–64 and 65 plus still have the highest proportions of TB cases in the other regions of England and Wales.

The median age of TB cases who were born abroad is younger than those born in the UK, suggesting that young people born outside the UK are at increased risk for TB disease. It is possible that age and sex differences in TB disease case rates are also influenced by ethnicity, but the national data that stratifies TB cases by sex, age, and ethnicity was not considered reliable at the time this document was written.

Although data on TB/HIV co-infection is limited by the matching methodology used, it appears that TB/HIV co-infection is most commonly found in those aged between 35–44, living in London, who were born abroad.

The 2001 treatment completion rate was significantly lower in pulmonary cases than in non-pulmonary cases. Multiple Drug Resistance (MDR) detected in isolates at the start of treatment decreased overall between 1994 and 2001, although isoniazid resistance increased during the same time period.

TB disease appears to require a longer period of hospital inpatient treatment than the average for all diagnostic categories. Pulmonary forms of TB account for the majority of completed TB hospital episodes and bed days in both England and Wales.

There may be some regional variation in BCG vaccination coverage of infants and children aged 10–15.

Finally, it is worth noting that national data on other groups at high risk for TB disease such as homeless people, drug and alcohol abusers, and those in prisons were not routinely collected in England and Wales at the time of writing.

Copyright © 2006, Royal College of Physicians of London.

For 2006 original guideline text, no part of the content may be reproduced in any form (including photocopying or storing it in any medium by electronic means and whether or not transiently or incidentally to some other issue of this publication) without the written permission of the Royal College of Physicians of London. Applications for the Royal College of Physicians of London's written permission to reproduce any part of this publication should be addressed to the publisher.

For 2011 updated text, the material may be freely reproduced for educational and not-for-profit purposes. No reproduction by or for commercial organisations, or for commercial purposes, is allowed without the express written permission of NICE.

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