Reversing the tide of the UK tuberculosis epidemic

Contamination and transmission of Mycobacteria in indoor environments of public buildings

OBJECTIVES

The aim of this study was to detect Mycobacterium tuberculosis complex, M. avium subsp. avium and M. intracellulare, Mycobacterium contamination and to explore the aerosol transmission of mycobacteria in public buildings in China.

METHODS

A total of 552 environmental samples, namely 165 aerosol, 199 water, 70 air duct dust, and 118 soil samples, were collected from 39 public buildings and analysed using nested polymerase chain reaction.

RESULTS

The positivity rate of Mycobacterium tuberculosis complex, M. avium subsp. avium and M. intracellulare in air samples were 0.6% and 1.8%, respectively. There was significant difference in the positivity rate of Mycobacterium aerosol among the three types of public building (χ² = 6.108, p = 0.047). No positive results of Mycobacterium tuberculosis complex and M. avium and M. intracellulare were obtained from cooling, tap, shower, or fountain water. The positivity rate of Mycobacterium for water samples was 31.7% (63/199). The positivity rate of Mycobacterium tuberculosis complex, M. avium subsp. avium and M. intracellulare, Mycobacterium in soil samples were 1.1%, 34.6% and 43.6%, respectively. There was significant difference in the positivity rate of M. avium and M. intracellulare (χ² = 47.219, p < 0.001) and Mycobacterium (χ² = 33.535, p < 0.001) in the different origins of soil samples.

CONCLUSIONS

Mycobacteria are widespread in public buildings. Mycobacterium tuberculosis complex, M. avium and M. intracellulare were simultaneously present in the air ducts of central air conditioning systems and indoor air in public buildings, which indicates that aerosol transmission is a potential route.

Utility of EBUS-TBNA in diagnosing mediastinal tuberculous lymphadenitis in East London

OBJECTIVES

To characterise and describe the diagnostic utility of Endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) in intrathoracic tuberculosis in a cohort of patients with mediastinal lymphadenopathy of unknown aetiology.

METHODS

Consecutive patients with intrathoracic lymphadenopathy undergoing EBUS-TBNA between 2012 and 2016 were identified. Demographic data, biopsy cytopathology and mycobacteriology results, HIV and vitamin D status, susceptibility results and final diagnoses were recorded. Pre- and post-procedure probability scores were assigned to each case to reflect the probability of tuberculosis.

RESULTS

315 cases were identified; 54 (17.1%) had tuberculosis and 261 (82.9%) had a non-tuberculosis diagnosis. amongst TB cases, the sensitivity of EBUS-TBNA was 59.3% (95% CI 45.06-72.14), specificity 100% (95% CI 98.19-100) and the negative predictive value (NPV) was 92.23% (95% CI 88.31-94.95). 19/54 (35%) TB cases were confirmed by EBUS mycobacterial culture and 13/54 (24.1%) by cytopathology.  33 (61.1%) of the TB cases, had a low to medium pre-test probability score assigned prior to EBUS-TBNA. Amongst EBUS culture-confirmed cases, we found a resistance rate of 10.5% to one or more first line TB drugs, with one case of multi-drug resistant TB.

CONCLUSIONS

We confirmed the utility of EBUS-TBNA in the diagnosis of intrathoracic tuberculosis in an undifferentiated cohort of patients with mediastinal lymphadenopathy of unknown aetiology and advocate sending samples for mycobacterial culture in all cases in high tuberculosis incidence areas.

The association between chronic kidney disease and tuberculosis; a comparative cohort study in England

BACKGROUND

People with end-stage kidney disease have an increased risk of active tuberculosis (TB). Previous systematic reviews have demonstrated that patients with chronic kidney disease (CKD) have increased risk of severe community-acquired infections. We investigated the association between CKD (prior to renal replacement therapy) and incidence of TB in UK General Practice.

METHODS

Using the UK Clinical Practice Research Datalink, 242,349 patients with CKD (stages 3-5) (estimated glomerular filtration rate < 60 mL/min/1.73 m2 for ≥3 months) between April 2004 and March 2014 were identified and individually matched (by age, gender, general practice and calendar time) to a control from the general population without known CKD. The association between CKD (overall and by stage) and incident TB was investigated using a Poisson regression analysis adjusted for age, gender, ethnicity, socio-economic status, chronic obstructive pulmonary disease (COPD) and diabetes.

RESULTS

The incidence of TB was higher amongst patients with CKD compared to those without CKD: 14.63 and 9.89 cases per 100,000 person-years. After adjusting for age, gender, ethnicity, socio-economic status, diabetes and COPD, the association between CKD and TB remained (adjusted rate ratio [RR] 1.42, 95% confidence interval [CI] 1.01-1.85). The association may be stronger amongst those from non-white ethnic minorities (adjusted RR 2.83, 95%CI 1.32-6.03, p-value for interaction with ethnicity = 0.061). Amongst those with CKD stages 3-5, there was no evidence of a trend with CKD severity.

CONCLUSIONS

CKD is associated with an increased risk of TB diagnosis in a UK General Practice cohort. This group of patients should be considered for testing and treating for latent TB.

Evaluation of prediagnosis emergency department presentations in patients with active tuberculosis: the role of chest radiography, risk factors and symptoms

INTRODUCTION

London has a high rate of tuberculosis (TB) with 2572 cases reported in 2014. Cases are more common in non-UK born, alcohol-dependent or homeless patients. The emergency department (ED) presents an opportunity for the diagnosis of TB in these patient groups. This is the first study describing the clinico-radiological characteristics of such attendances in two urban UK hospitals for pulmonary TB (PTB) and extrapulmonary TB (EPTB).

METHODS

We conducted a retrospective cohort study using the London TB Register (LTBR) and hospital records to identify patients who presented to two London ED's in the 6 months prior to their ultimate TB diagnosis 2011-2012.

RESULTS

397 TB cases were identified. 39% (154/397) had presented to the ED in the 6 months prior to diagnosis. In the study population, the presence of cough, weight loss, fever and night sweats only had prevalence rates of 40%, 34%, 34% and 21%, respectively. Chest radiography was performed in 76% (117/154) of patients. For cases where a new diagnosis of TB was suspected, 73% (41/56) had an abnormal radiograph, compared with 36% (35/98) of patients where it was not. There was an abnormality on a chest radiograph in 73% (55/75) of PTB cases and also in 40% (21/52) of EPTB cases where a film was requested.

CONCLUSIONS

A large proportion of patients with TB present to ED. A diagnosis was more likely in the presence of an abnormal radiograph, suggesting opportunities for earlier diagnosis if risk factors, symptoms and chest radiograph findings are combined.

Equitable tuberculosis care in the North West of England: analysis of tuberculosis cohort review data

BACKGROUND: In the United Kingdom, tuberculosis (TB) predominantly affects the most deprived populations, yet the extent to which deprivation affects TB care outcomes is unknown.

METHODS: Since 2011, the North West TB Cohort Audit collaboration has undertaken quarterly reviews of outcomes against consensus-defined care standard indicators for all individuals notified with TB. We investigated associations between adverse TB care outcomes and Index of Multiple Deprivation (IMD) 2010 scores measured at lower super output area of residence using logistic regression models.

RESULTS: Of 1831 individuals notified with TB between 2011 and 2014, 62% (1131/1831) came from the most deprived national quintile areas. In single variable analysis, greater deprivation was significantly associated with increased likelihood of the completion of a standardised risk assessment (OR 2.99, 95%CI 5.27–19.65) and offer of a human immunodeficiency virus test (OR 1.72, 95%CI 1.10–2.62). In multivariable analysis, there were no significant associations.

CONCLUSIONS: TB patients in the most deprived areas had similar care indicators across a range of standards to those of individuals living in the more affluent areas, suggesting that the delivery of TB care in the North West of England is equitable. The extent to which the cohort review process contributes to, and sustains, this standard of care deserves further study.

Mind the gap: TB trends in the USA and the UK, 2000-2011

BACKGROUND

TB remains a major public health concern, even in low-incidence countries like the USA and the UK. Over the last two decades, cases of TB reported in the USA have declined, while they have increased substantially in the UK. We examined factors associated with this divergence in TB trends between the two countries.

METHODS

We analysed all cases of TB reported to the US and UK national TB surveillance systems from 1 January 2000 through 31 December 2011. Negative binominal regression was used to assess potential demographic, clinical and risk factor variables associated with differences in observed trends.

FINDINGS

A total of 259,609 cases were reported. From 2000 to 2011, annual TB incidence rates declined from 5.8 to 3.4 cases per 100,000 in the USA, whereas in the UK, TB incidence increased from 11.4 to 14.4 cases per 100,000. The majority of cases in both the USA (56%) and the UK (64%) were among foreign-born persons. The number of foreign-born cases reported in the USA declined by 15% (7731 in 2000 to 6564 in 2011) while native-born cases fell by 54% (8442 in 2000 to 3883 in 2011). In contrast, the number of foreign-born cases reported in the UK increased by 80% (3380 in 2000 to 6088 in 2011), while the number of native-born cases remained largely unchanged (2158 in 2000 to 2137 in 2011). In an adjusted negative binomial regression model, significant differences in trend were associated with sex, age, race/ethnicity, site of disease, HIV status and previous history of TB (p<0.01). Among the foreign-born, significant differences in trend were also associated with time since UK or US entry (p<0.01).

INTERPRETATION

To achieve TB elimination in the UK, a re-evaluation of current TB control policies and practices with a focus on foreign-born are needed. In the USA, maintaining and strengthening control practices are necessary to sustain the progress made over the last 20 years.

School life expectancy and risk for tuberculosis in Europe

OBJECTIVE

This study aims to investigate the effect of country-level school life expectancy on Tuberculosis (TB) incidence to gain further understanding of substantial variation in TB incidence across Europe.

METHODS

An ecological study examined the prospective association between baseline country-level education in 2000 measured by school life expectancy and TB incidence in 2000-2010 in 40 countries of the WHO European region using quantile regression. Subsequently, to validate the ecological associations between education and TB incidence, an individual-level analysis was performed using case-based data in 29 EU/EEA countries from the European Surveillance System (TESSy) and simulating a theoretical control group.

RESULTS

The ecological analysis showed that baseline school life expectancy had a negative prospective association with TB incidence. We observed consistent negative effects of school life expectancy on individuals' TB infections prospectively.

CONCLUSIONS

These findings suggests that country-level education is an important determinant of individual-level TB infection in the region, and in the absence of a social determinants indicator that is routinely collected for reportable infectious diseases, the adoption of country-level education for reportable infectious diseases would significantly advance the field.

Higher Rate of Tuberculosis in Second Generation Migrants Compared to Native Residents in a Metropolitan Setting in Western Europe

BACKGROUND

In Western Europe, migrants constitute an important risk group for tuberculosis, but little is known about successive generations of migrants. We aimed to characterize migration among tuberculosis cases in Berlin and to estimate annual rates of tuberculosis in two subsequent migrant generations. We hypothesized that second generation migrants born in Germany are at higher risk of tuberculosis compared to native (non-migrant) residents.

METHODS

A prospective cross-sectional study was conducted. All tuberculosis cases reported to health authorities in Berlin between 11/2010 and 10/2011 were eligible. Interviews were conducted using a structured questionnaire including demographic data, migration history of patients and their parents, and language use. Tuberculosis rates were estimated using 2011 census data.

RESULTS

Of 314 tuberculosis cases reported, 154 (49.0%) participated. Of these, 81 (52.6%) were first-, 14 (9.1%) were second generation migrants, and 59 (38.3%) were native residents. The tuberculosis rate per 100,000 individuals was 28.3 (95CI: 24.0-32.6) in first-, 10.2 (95%CI: 6.1-16.6) in second generation migrants, and 4.6 (95%CI: 3.7-5.6) in native residents. When combining information from the standard notification variables country of birth and citizenship, the sensitivity to detect second generation migration was 28.6%.

CONCLUSIONS

There is a higher rate of tuberculosis among second generation migrants compared to native residents in Berlin. This may be explained by presumably frequent contact and transmission within migrant populations. Second generation migration is insufficiently captured by the surveillance variables country of birth and citizenship. Surveillance systems in Western Europe should allow for quantifying the tuberculosis burden in this important risk group.

Risk of tuberculosis in patients with diabetes: population based cohort study using the UK Clinical Practice Research Datalink

BACKGROUND

Previous cohort studies demonstrate diabetes as a risk factor for tuberculosis (TB) disease. Public Health England has identified improved TB control as a priority area and has proposed a primary care-based screening program for latent TB. We investigated the association between diabetes and risk of tuberculosis in a UK General Practice cohort in order to identify potential high-risk groups appropriate for latent TB screening.

METHODS

Using data from the UK Clinical Practice Research Datalink we constructed a cohort of patients with incident diabetes. We included 222,731 patients with diabetes diagnosed from 1990-2013 and 1,218,616 controls without diabetes at index date who were matched for age, sex and general practice. The effect of diabetes was explored using a Poisson analysis adjusted for age, ethnicity, body mass index, socioeconomic status, alcohol intake and smoking. We explored the effects of age, diabetes duration and severity. The effects of diabetes on risk of incident TB were explored across strata of chronic disease care defined by cholesterol and blood pressure measurement and influenza vaccination rates.

RESULTS

During just under 7 million person-years of follow-up, 969 cases of TB were identified. The incidence of TB was higher amongst patients with diabetes compared with the unexposed group: 16.2 and 13.5 cases per 100,000 person-years, respectively. After adjustment for potential confounders the association between diabetes and TB remained (adjusted RR 1.30, 95 % CI 1.01 to 1.67, P = 0.04). There was no evidence that age, time since diagnosis and severity of diabetes affected the association between diabetes and TB. Diabetes patients with the lowest and highest rates of chronic disease management had a higher risk of TB (P <0.001 for all comparisons).

CONCLUSIONS

Diabetes as an independent risk factor is associated with only a modest overall increased risk of TB in our UK General Practice cohort and is unlikely to be sufficient cause to screen for latent TB. Across different consulting patterns, diabetes patients accessing the least amount of chronic disease care are at highest risk for TB.

Engaging new migrants in infectious disease screening: a qualitative semi-structured interview study of UK migrant community health-care leads

Migration to Europe - and in particular the UK - has risen dramatically in the past decades, with implications for public health services. Migrants have increased vulnerability to infectious diseases (70% of TB cases and 60% HIV cases are in migrants) and face multiple barriers to healthcare. There is currently considerable debate as to the optimum approach to infectious disease screening in this often hard-to-reach group, and an urgent need for innovative approaches. Little research has focused on the specific experience of new migrants, nor sought their views on ways forward. We undertook a qualitative semi-structured interview study of migrant community health-care leads representing dominant new migrant groups in London, UK, to explore their views around barriers to screening, acceptability of screening, and innovative approaches to screening for four key diseases (HIV, TB, hepatitis B, and hepatitis C). Participants unanimously agreed that current screening models are not perceived to be widely accessible to new migrant communities. Dominant barriers that discourage uptake of screening include disease-related stigma present in their own communities and services being perceived as non-migrant friendly. New migrants are likely to be disproportionately affected by these barriers, with implications for health status. Screening is certainly acceptable to new migrants, however, services need to be developed to become more community-based, proactive, and to work more closely with community organisations; findings that mirror the views of migrants and health-care providers in Europe and internationally. Awareness raising about the benefits of screening within new migrant communities is critical. One innovative approach proposed by participants is a community-based package of health screening combining all key diseases into one general health check-up, to lessen the associated stigma. Further research is needed to develop evidence-based community-focused screening models - drawing on models of best practice from other countries receiving high numbers of migrants.

'Complex' but coping: experience of symptoms of tuberculosis and health care seeking behaviours--a qualitative interview study of urban risk groups, London, UK

BACKGROUND

Tuberculosis awareness, grounded in social cognition models of health care seeking behaviour, relies on the ability of individuals to recognise symptoms, assess their risk and access health care (passive case finding). There is scant published research into the health actions of 'hard-to-reach' groups with tuberculosis, who represent approximately 17% of the London TB caseload. This study aimed to analyse patients' knowledge of tuberculosis, their experiences of symptoms and their health care seeking behaviours.

METHODS

Qualitative interviews were conducted with 17 participants, predominantly homeless and attending a major tuberculosis centre in London, UK. Most had complex medical and social needs including drug and alcohol use or immigration problems affecting entitlement to social welfare. Analytical frameworks aimed to reflect the role of broader social structures in shaping individual health actions.

RESULTS

Although participants demonstrated some knowledge of tuberculosis their awareness of personal risk was low. Symptoms commonly associated with tuberculosis were either not recognised or were attributed to other causes for which participants would not ordinarily seek health care. Many accessed health care by chance and, for some, for health concerns other than tuberculosis.

CONCLUSIONS

Health education, based on increasing awareness of symptoms, may play a limited role in tuberculosis care for populations with complex health and social needs. The findings support the intensification of outreach initiatives to identify groups at risk of tuberculosis and the development of structured care pathways which support people into prompt diagnosis and treatment.