Tuberculosis In London Research Articles

Outcomes of a residential respite service for homeless people with tuberculosis in London, UK: a cross-sectional study.

Many countries are seeking to eliminate tuberculosis (TB), but incidence remains high in socially excluded groups such as people experiencing homelessness. There is limited research into the effectiveness of residential respite services (RRS), which provide accomodation and social and clinical support for homeless people with active TB. We used a register of all cases of TB diagnosed in London between 1 January 2010 and 3 October 2019 to compare characteristics and outcomes of patients treated in an RRS with patients receiving standard care. The primary outcome was successful treatment completion. We used logistic regression to compare likelihood of completing treatment, and simulation to estimate the absolute change in treatment completion resulting from this service. A total of 78 homeless patients finished an episode of TB treatment at the RRS. Patients treated in the RRS were more likely than patients treated in standard care to have clinical and social risk factors including drug resistance, history of homelessness, drug or alcohol use, and need for directly observed therapy. After adjusting for these factors, patients treated in the RRS had 2.97 times the odds of completing treatment (95% CI = 1.44-6.96). Treatment ended in failure for 8/78 patients treated in the RRS (10%, 95% CI = 5%-20%). We estimated that in the absence of the RRS, treatment would have ended in failure for 17/78 patients (95% CI = 11-25). The residential respite service for homeless TB patients with complex social needs was associated with better treatment outcomes.

High-tech ‘Find and Treat’ service tackles tuberculosis in London's homeless

High-tech ‘Find and Treat’ service tackles tuberculosis in London's homeless

Why has the incidence of tuberculosis not reduced in London during the COVID-19 pandemic?

The rate of tuberculosis in London, UK, has not reduced during the COVID-19 pandemic. This might be surprising given that tuberculosis is airborne, and suggests important lessons about the transmission and treatment of the disease.

1406. Hepatitis B and C Prevalence in Patients with Active and Latent Tuberculosis in an Ethnically Diverse Area of London, UK

BackgroundNorth West London has one of the highest tuberculosis (TB) rates in the UK, at 24.8 per 10,000. The UK prevalence of hepatitis B virus (HBV) is 0.1-0.5% and for hepatitis C virus (HCV) is 0.5-1%. Chronic infection with HBV or HCV can lead to an increased risk of adverse treatment outcomes, such as drug-induced liver injury (DILI) in patients with active or latent TB. National guidelines recommend routinely screening for HBV/HCV prior to initiating TB treatment. Our objectives were to 1) evaluate the HBV/HCV screening practice in local TB clinics, 2) establish the prevalence of HBV/HCV in patients receiving TB treatment.MethodsRetrospective analysis of laboratory and medical records of patients treated for active or latent TB identified from the London TB register and clinic records from 01/01/2018 to 31/12/2020 from London North West NHS Trust.Results1409 patients received treatment for TB during the time period of interest; 574 (40.7%) had active disease and 835 (59.3%) had latent infection. 966/1409 patients (68.56%) were screened for HBV and HCV. 55.9% of the active TB group and 77.2% of the latent infection group were tested. 66 (6.8%) patients had isolated anti-HBc positivity, 22 (2.3%) were HBV surface antigen positive and 8 (0.8%) were HCV-antibody positive. HBV surface antigens were more prevalent in active TB patients: 9/321 (2.80%) with active TB versus 13/645 (2.02%) with latent TB. 36/321 (11.21%) active TB patients had HBV core antibodies compared to 30/645 (4.65%) latent TB patients (p < 0.001). Three patients started antiviral treatment following their viral hepatitis diagnosis (one with HBV, two with HCV).ConclusionThe prevalence of chronic HBV in the study population was higher than the estimated UK prevalence. Fifteen diagnoses of hepatitis were new, allowing specialist referral for monitoring of fibrosis and development of hepatocellular carcinoma. Three patients required hepatitis treatment. 6.8% of patients were positive for anti-HBc and therefore identified as being at future risk of HBV reactivation if requiring immunosuppressive therapies.TB disproportionately affects marginalised communities; screening for viral hepatitis in TB clinic represents an opportunity to target these hard-to-reach groups to maximise the impact of public health interventions.Disclosures All Authors: No reported disclosures

Delays in diagnosis of osteoarticular tuberculosis

Background: Osteoarticular Mycobacterium tuberculosis infection is uncommon, accounting for 2–5% of tuberculosis (TB) cases worldwide. Presenting symptoms may be non-specific, leading to a delay in diagnosis and treatment. We reviewed data from a cohort of patients with osteoarticular TB in an ethnically diverse area of London with the highest TB endemicity in the UK. Methods and materials: Retrospective analysis of laboratory and medical records, radiology and microbiology results of patients with osteoarticular TB identified from the London TB register between January 2016 and October 2019 from London North West University Healthcare NHS Trust. Results: 74 patients were identified with median age 36 years (range 11–82). 59.5% were South Asian, 23% were from Sub-Saharan Africa. None were HIV positive; 16.2% had type 2 diabetes. The commonest site of infection was spine (46 patients), followed by sternum (8) and ankle (5). Twenty (27%) had multifocal disease with 14.9% having concurrent pulmonary TB. A 50% of patients with spinal TB had radiological evidence of multilevel disease. Patients with spinal TB were more likely to present with constitutional symptoms than patients with TB at other osteoarticular sites (48.8% vs. 10.7%, p < 0.001). Forty cases were culture-positive with 38 fully-sensitive, 1 MDR and 1 isoniazid-resistant. Twenty-nine patients had positive tissue or pus GeneXpert MTB/RIF®. A 42% of patients were treated empirically on a clinico-radiological basis. Mean number of days from symptom onset to initiation of treatment was 187.5 days. Patients with spinal TB had fewer days between onset of symptoms and commencing treatment compared to patients with TB at other sites (mean 99.8 days vs. 328.4 days, p < 0.01). Most patients (73%) received extended treatment between 9 and 12 months. Twenty-five required surgical intervention including abscess drainage (16), spinal fixation (1) and joint replacement (2). 32.8% of patients had residual symptoms after completing treatment including limb weakness, flaccid paralysis and pain. Two patients were lost to follow up and 3 died before completing treatment. Conclusion: This cohort review identifies a significant delay in diagnosing osteoarticular TB, resulting in disability and morbidity. Clinicians should therefore give early consideration to osteoarticular TB in patients presenting with bone or joint pain, even in the absence of constitutional symptoms.

Extraspinal articular tuberculosis: An 11-year retrospective study of demographic features and clinical outcomes in East London

ObjectivesTo describe demographic features, clinical outcomes and diagnostic delay amongst patients with extra-spinal articular tuberculosis (TB) in a low-incidence setting. MethodsCases of TB treated at our institution between 2004 and 2014 were identified via the London TB register (LTBR). Demographic features of extra-spinal articular TB cases were compared to controls with TB at all other sites. For articular cases (excluding individuals <16 years or with spinal TB without peripheral joint involvement) clinical data were retrospectively collected. Results6,146 TB patients were identified over the study period; 146 (2.4%) cases had extra-spinal articular infection. There was no difference in median age between extra-spinal articular TB cases and controls with TB at other sites (31 vs 32 years, p = 0.57). Articular cases were more likely to be male (70.6% vs 59.5%, p = 0.007), Bangladeshi (28.7% vs 18.0%) or Pakistani (24.0% vs 16.1%) and were less likely to be Black-African (9.5% vs 19.8%) (p < 0.001). 93 cases were included in the case series; 85 (88.5%) were migrants and 83 (89.2%) were South Asian. Knee and elbow joints were affected in 22 (23.7%) and 18 (19.4%) cases respectively. The median durations of pre-healthcare and healthcare associated delay were 16 and 6 weeks respectively. Where mycobacterial culture was performed, 57/75 (76%) were positive for Mycobacterium tuberculosis. 86 (92.5%) cases received standard quadruple therapy for a median of 6 months (IQR 6–9). Recurrence of TB infection occurred in 4 (4.3%) cases and there were no TB related deaths. Seven (7.6%) cases required surgical intervention. ConclusionsExtra-spinal articular TB more commonly affected men and people of South Asian ethnicity. Significant diagnostic delays were identified, including avoidable healthcare-associated delays.

The NHS visitor and migrant cost recovery programme \u2013 a threat to health?

BackgroundIn April 2014 the UK government launched the ‘NHS Visitor and Migrant Cost Recovery Programme Implementation Plan’ which set out a series of policy changes to recoup costs from ‘chargeable’ (largely non-UK born) patients. In England, approximately 75% of tuberculosis (TB) cases occur in people born abroad. Delays in TB treatment increase risk of morbidity, mortality and transmission in the community. We investigated whether diagnostic delay has increased since the Cost Recovery Programme (CRP) was introduced.MethodsThere were 3342 adult TB cases notified on the London TB Register across Barts Health NHS Trust between 1st January 2011 and 31st December 2016. Cases with missing relevant information were excluded. The median time between symptom onset and treatment initiation before and after the CRP was calculated according to birthplace and compared using the Mann Whitney test. Delayed diagnosis was considered greater or equal to median time to treatment for all patients (79 days). Univariable logistic regression was used to manually select exposure variables for inclusion in a multivariable model to test the association between diagnostic delay and the implementation of the CRP.ResultsWe included 2237 TB cases. Among non-UK born patients, median time-to-treatment increased from 69 days to 89 days following introduction of CRP (p < 0.001). Median time-to-treatment also increased for the UK-born population from 75.5 days to 89.5 days (p = 0.307). The multivariable logistic regression model showed non-UK born patients were more likely to have a delay in diagnosis after the CRP (adjOR 1.37, 95% CI 1.13–1.66, p value 0.001).ConclusionSince the introduction of the CRP there has been a significant delay for TB treatment among non-UK born patients. Further research exploring the effect of policies restricting access to healthcare for migrants is urgently needed if we wish to eliminate TB nationally.

Evaluation of the BD MAX™ MDR-TB assay in a real-world setting for the diagnosis of pulmonary and extra-pulmonary TB

Tuberculosis in London occurs at a rate of 19 cases per 100,000 population, with a significant proportion diagnosed as extra-pulmonary infection. At Barts Health NHS Trust, our TB rates are much higher than the London average and approximately 60% cases are extra-pulmonary in nature. We evaluated the BD MAX™ MDR-TB assay as a molecular tool for rapid diagnosis of TB. One hundred twenty-eight specimens, encompassing pulmonary (70) and extra-pulmonary (58) infection, were tested using the BD MAX™ MDR-TB assay and compared with smear and liquid culture results, to determine PCR performance. The BD MAX™ MDR-TB assay was also compared with the Xpert MTB/RIF assay, where applicable. TB was successfully detected in 50/66 Mycobacterium tuberculosis culture positive specimens, with additional detections in 2 of the culture negative specimens. The BD MAX™ MDR-TB assay demonstrated higher sensitivity with the pulmonary samples (92%) compared with the extra-pulmonary samples (52%), although the performance with fluids and biopsies demonstrated greater potential than the remaining extra-pulmonary samples. Rifampicin and/or isoniazid resistance was successfully detected by the BD MAX™ in 2/3 samples, where WGS susceptibility results were available. The BD MAX™ MDR-TB assay was comparable with the performance of the Xpert MTB/RIF assay. TB can successfully be diagnosed, in both pulmonary and extra-pulmonary samples, using the BD MAX™ MDR-TB assay.

Presentation and healthcare delays among people with tuberculosis in London, and the impact on treatment outcome

BackgroundA quarter of London’s pulmonary tuberculosis (TB) patients have over 4 months of delay. Late diagnosis increases disease severity and the risk of transmission. We aim to classify delays, identify...

Complications of miliary tuberculosis: low mortality and predictive biomarkers from a UK cohort

BackgroundUntreated, miliary tuberculosis (TB) has a mortality approaching 100%. As it is uncommon there is little specific data to guide its management. We report detailed data from a UK cohort of patients with miliary tuberculosis and the associations and predictive ability of admission blood tests with clinical outcomes.MethodsRoutinely collected demographic, clinical, blood, imaging, histopathological and microbiological data were assessed for all patients with miliary TB identified from the London TB register from 2008 to 2012 from Northwest London Hospitals NHS Trust. Multivariable logistic regression was used to assess factors independently associated with the need for critical care intervention. Receiver operator characteristics (ROC) were calculated to assess the discriminatory ability of admission blood tests to predict clinical outcomes.ResultsFifty-two patients were identified with miliary tuberculosis, of whom 29% had confirmed central nervous system (CNS) involvement. Magnetic resonance imaging (MRI) was more sensitive than computed tomography (CT) or lumbar puncture for detecting CNS disease. Severe complications were frequent, with 15% requiring critical care intervention with mechanical ventilation. This was independently associated with admission hyponatraemia and elevated alanine aminotransferase (ALT). Having an admission sodium ≥125 mmol/L and an ALT <180 IU/L had 82% sensitivity and 100% specificity for predicting a favourable outcome with an area under the ROC curve (AUC) of 0.91. Despite the frequency of severe complications, one-year mortality was low at 2%.ConclusionsAlthough severe complications of miliary tuberculosis were frequent, mortality was low with timely access to critical care intervention, anti-tuberculous therapy and possibly corticosteroid use. Clinical outcomes could accurately be predicted using routinely collected biochemistry data.

Multiple large clusters of tuberculosis in London: a cross-sectional analysis of molecular and spatial data.

Large outbreaks of tuberculosis (TB) represent a particular threat to disease control because they reflect multiple instances of active transmission. The extent to which long chains of transmission contribute to high TB incidence in London is unknown. We aimed to estimate the contribution of large clusters to the burden of TB in London and identify risk factors.We identified TB patients resident in London notified between 2010 and 2014, and used 24-locus mycobacterial interspersed repetitive units–variable number tandem repeat strain typing data to classify cases according to molecular cluster size. We used spatial scan statistics to test for spatial clustering and analysed risk factors through multinomial logistic regression.TB isolates from 7458 patients were included in the analysis. There were 20 large molecular clusters (with n>20 cases), comprising 795 (11%) of all cases; 18 (90%) large clusters exhibited significant spatial clustering. Cases in large clusters were more likely to be UK born (adjusted odds ratio 2.93, 95% CI 2.28–3.77), of black-Caribbean ethnicity (adjusted odds ratio 3.64, 95% CI 2.23–5.94) and have multiple social risk factors (adjusted odds ratio 3.75, 95% CI 1.96–7.16).Large clusters of cases contribute substantially to the burden of TB in London. Targeting interventions such as screening in deprived areas and social risk groups, including those of black ethnicities and born in the UK, should be a priority for reducing transmission.

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

IntroductionLondon 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...

PTH-069 Active Tuberculosis in Patients with Inflammatory Bowel Disease After Treatment with Anti-TNF Therapy

Introduction Anti-tumour necrosis factor agents (anti–TNF) are major advances in the management of inflammatory bowel disease (IBD) however they are associated with a 5 fold increased risk of Mycobacterium tuberculosis (TB) infection. All patients should be screened for latent TB infection (LTBI) prior to anti-TNF therapy. Here, we review active TB cases after anti-TNF therapy to identify lessons to be learned. Methods All patients with IBD treated with anti-TNF between March 2007-November 2015 were identified from pharmacy database. Those who developed active TB were identified from the London TB register. Clinical and electronic notes were reviewed. LTBI screening is with history, Chest X-Ray (CXR) and tuberculin skin test (TST) before July 2013 or Quantiferon Gold Assay (QFT-G) after July 2013. Results Of 596 patients treated with anti-TNF, 6 had active TB. 5 had Crohn’s and 1 had Ulcerative Colitis. 3 were male, none had HIV. Age range was 24–49 years. 5 were Caucasian, 1 was UK born but of Pakistani origin. 3 were on Adalimumab (ADA) at time of TB diagnosis and 2 on Infliximab (IFX), 3 were on at least 1 other immunosuppressive. 1 was not on anti-TNFs at TB diagnosis but received IFX 3 months earlier. Time from initiation of anti-TNF to TB diagnosis ranged from 3–41 months (median:13, IQR = 32). 3 had culture confirmed TB, 1 was MTB complex PCR positive but culture negative and 2 had presumed TB. All isolated cultures were fully sensitive. 2 had miliary TB, 2 abdominal TB, 1 pleuro-pulmonary TB and 1 both pulmonary and pericardial TB. Treatment duration was 6–12 months, 5 patients completed treatment and 1 remains on treatment. 3 had prior vaccination for TB, 1 did not and the vaccination status of 2 was unknown. 4 patients had negative TSTs pre-anti-TNF (3 while immunosuppressed), 1 had an indeterminate QFT-G test (while immunosuppressed) and 1 had neither. All patients had normal CXR prior to anti-TNF. No patients received LTBI treatment. Conclusion All cases were considered low epidemiological risk for LTBI . None had a positive TST or QFT-G, however the risk of false negatives is high in immunosuppression. As some patients screened may receive prolonged and recurrent courses of anti-TNF, we recommend discussion around when patients should be rescreened. It is unclear if these cases represent de novo infection or reactivation of latent disease but re-screening may have identified them at the latent stage. As it is not possible to prevent all cases of active TB, there must be continued focus on prompt diagnosis and treatment, alongside comprehensive screening by working with local TB services. Disclosure of Interest None Declared

Development of an open source tool for mapping disease clusters

BackgroundMapping is an important step in investigations of infectious disease outbreaks. Despite advances in molecular characterisation of pathogens that allow delineation of outbreaks with greater precision, geospatial methods that complement these analyses are rarely used in real time. Barriers include lack of flexibility, expense of specialised software, and the need for trained personnel. This study aimed to develop a tool with free, open source software that could be used by public health professionals to display clusters of disease on a map, and to demonstrate its utility through the exemplar of molecular clusters of tuberculosis in London. MethodsWe developed a bespoke interactive mapping tool using Shiny, a web application framework for the statistical software package, R. Mapping was enabled using Leaflet, a JavaScript library for interactive mapping, through the R package leaflet. Data were extracted from the Enhanced Tuberculosis Surveillance System for cases of tuberculosis with a residential postcode in London, who were part of a molecular cluster, and were notified between Jan 1, 2010, and Dec 31, 2013. FindingsData subsets can be interactively displayed on the basis of cluster name, notification date, demographics, and reported risk factors. In addition to mapping, epidemic curves and summary tables are automatically produced. The tool was used to explore 3194 cases of tuberculosis in 767 clusters in London, and allowed rapid overview of the geographical, temporal, and epidemiological features to support cluster investigation. InterpretationGeographical displays of molecular data can enhance understanding of disease transmission. Advantages of the tool developed in this study include: flexibility, allowing user-defined subsets of data in any geographical location to be displayed; potential adaptability to other geocoded health or other contextual data; and a web interface, which is user-friendly, needs minimal training to operate, and does not require upload of identifiable information to the internet. A potential limitation is maintenance of code, although the use of open source software also benefits from support and improvement from the wider developer community. Future work will involve testing of the tool with potential users to assess its utility in practice. FundingCMS is funded by the Farr Institute of Health Informatics Research.

A risk calculator for multidrug-resistant tuberculosis in London, UK

BackgroundRapid nucleic acid amplification technologies provide a fast and effective way to diagnose multidrug-resistant (MDR) tuberculosis. However, the number of false positive results produced by overtesting in low risk groups is a concern. With present estimates of the burden of MDR tuberculosis in the UK and rapid test sensitivity and specificity, the expected positive predictive value for testing all patients with tuberculosis is 0·47. Treatment for MDR tuberculosis is time-consuming and expensive, with severe side-effects for patients. Therefore an accessible risk calculator that can be used by clinicians to effectively target rapid testing is needed. MethodsUsing enhanced tuberculosis surveillance data collected through the London TB Register (a web-based system used by all TB clinics within the city) from 2009 to 2013, we developed a multivariable risk prediction model based on a-priori risk factors of MDR tuberculosis in London. Bootstrapping was used to internally validate the model, and external validation was done with national tuberculosis data from the same time period. FindingsOf 7292 individuals, 134 (1·83%) tested positive for MDR tuberculosis. In a multivariable penalised logistic regression model, the strongest risk factors associated with MDR tuberculosis included previous diagnosis, the burden of MDR tuberculosis in a patient's country of birth, recent arrival in the UK if foreign born, and age, with younger individuals at higher risk (appendix). The calibration slope was 0·90 after internal validation, and the area under the receiver operating characteristic curve (AUC) decreased from 0·73 to 0·70; this small reduction suggested satisfactory performance. Non-parametric calibration curves indicated accurate prediction for most patients, but with overestimated risk predicted for higher risk individuals. On an external dataset of 9652 patients, AUC was 0·74 with a calibration slope of 0·99. If only higher risk (>2%) patients were rapidly tested, we estimated that the positive predictive value would increase to 0·65. InterpretationThe model has been developed into a working calculator in Excel; the algorithms could also be integrated into surveillance registers to support embedding into clinical practice. Future research could include health economic work to help identify a range of cut-off risks at which testing is worthwhile. The model would need validating with local data before use in other countries. FundingOD is supported by a National Institute for Health Research (NIHR) Research Methods Fellowship.

S60 C - Reactive Protein Reflects Mycobacterial Load In Active Tuberculosis But Cannot Be Used As A Rule-out Diagnostic Test

Background Measurement of the C-reactive protein (CRP) is widely available and is often part of the diagnostic evaluation of patients with suspected Tuberculosis (TB) yet there are little published data regarding its use in this context. We sought to determine CRP’s relationship with TB disease and whether normal CRP levels were seen in those without active TB. Method We undertook a retrospective review of electronic records from the London TB service between 2004–2013, obtained blood results from hospital computer systems and reviewed case-notes where there was uncertainty regarding sites of disease or availability of culture results. Results Using data from 533 subjects with active TB, 23% of all cases and 16.5% of culture-confirmed cases had a CRP of ≤5 mg/L. Individuals with HIV co-infection had significantly higher median CRP (see Table). There was a significantly higher CRP in smear-positive pulmonary disease and those with a positive culture. Sites of disease that could be expected to have a high mycobacterial load (e.g. pulmonary disease and disseminated disease) had a significantly higher CRP than those such as skin, lymph node or CNS disease, where the mycobacterial load is typically low in HIV negative subjects. HIV status, site of disease and culture status remained significantly associated with CRP in a multivariable linear regression analysis. Conclusions These data suggest that CRP cannot be used as a rule-out test for active TB but does reflect mycobacterial load. This has clinical implications given that individuals with a high mycobacterial load may be more infectious (and hence require enhanced contact tracing), be at greater risk of developing drug resistance if non-adherent, and may require prolonged duration of treatment.

P183 Endobronchial Ultrasound And Tuberculosis: Beware The Non-caseating Granuloma

Introduction Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is now the standard of care for investigating intra-thoracic lymphadenopathy. Although well validated in malignancy and sarcoidosis, the literature for intra-thoracic tuberculous lymphadenitis is limited. Previous work from neighbouring London boroughs reported a sensitivity (histology or microbiology consistent with tuberculosis (TB)) for TB of 94% with positive TB culture in 47% of 156 patients Methods We examined retrospectively all EBUS-TBNA procedures performed at a London district general hospital between April 2010 and January 2014. Patients were referred to our EBUS service from our own hospital and two local centres. All patients were assessed clinically prior to the procedure and underwent a CT scan. Bronchoscopy reporting software was used to identify all EBUS procedures. Patient notes, clinic letters, electronic patient records and the London TB Register (LTBR) were used to obtain clinical information then matched with pathological and microbiological results. All patients were followed up for a minimum of 6 months. Results 363 patients were included. The overall sample yield (either lymph node or tumour identified) was 94%. 63 cases of tuberculosis were identified and EBUS-TBNA had been diagnostic in 57 (90%). Pathological findings were consistent with TB in 84% of cases and culture was positive in 62%. Culture identified 5 cases of drug resistance. Where caseating granulomas were identified, 18/25 cases were culture positive and 15/23 where non-caseating granulomas were identified (p = 0.76). In addition, where necrotic material was obtained 3/5 samples were culture positive and where reactive lymph nodes were identified 4/9 samples were culture positive. Conclusion EBUS-TBNA is a useful tool in the investigation of intra-thoracic tuberculous lymphadenitis. We show the possibility of achieving higher culture positivity from that reported in the literature. It highlights the importance of the TB culture for definitive diagnosis and detecting drug resistance. It is important to examine these findings in the context of appropriate clinical information and investigations.

P185 Improving The Accuracy Of Microbiological Diagnosis Of Tb Lymphadenitis - Is A Multidisciplinary Approach Necessary?

Introduction The gold standard for diagnosing tuberculosis (TB) is from culture of the organism from fluid or tissue. Histological analysis of surgical specimens is well-established, but microbiological analysis is less frequent. Our trust serves a population with a high incidence of TB. Therefore, patients who present with lymphadenopathy should always be considered for a diagnosis of TB and all specimens sent for microbiological and histological diagnosis. Methods A retrospective analysis was undertaken of all patients diagnosed with TB lymphadenitis between 2009–2013 using the London TB Register (LTBR), case notes and laboratory data to identify the proportion diagnosed with microbiology data compared with histology data. Results 324 patients were diagnosed with TB lymphadenitis from LTBR, of which 73% (235/324) had lymph node (LN) specimens taken for microbiological or histological diagnosis. 233 patients had extrathoracic disease alone, of which 62% (144/233) had LN tissue sent for microbiology with 74% yielding a positive culture. 75 patients had intrathoracic disease, of which 31% (23/75) had LN tissue sent for microbiology with 52% yielding a positive culture. In both groups, a greater percentage of LN tissue was sent for histo-cytological analysis than microbiology (see figure). 75% (12/16) of patients with combined extrathoracic and intrathoracic disease had specimens sent for microbiology. 83% (11/16) gained a positive microbiological diagnosis from lymph node sampling. Conclusion Microbiological specimens were more likely to be sent in patients with extrathoracic disease compared to those with intrathoracic disease. This may partly be explained by the fact that all intrathoracic lymph node sampling during this study period was undertaken at other centres, mostly through referrals from the lung cancer MDT. Therefore TB may not have been considered as a possible diagnosis. However, a significant proportion of surgical samples taken locally did not have microbiology specimens sent, which potentially may have impacted on treatment outcomes. This review highlights that more education should be undertaken locally with surgical and radiology departments and the lung MDT, emphasising the need for all lymph node specimens to be sent for both microbiological and histological analysis.

P282 A Prospective Study To Determine The Accuracy Of Self-reported Smoking Habits In Patients With Tuberculosis

Background Smoking is an independent risk factor for tuberculosis infection, disease and mortality. It is therefore important that clinicians can identify patients who are actively smoking in order to provide optimal care. The reliability of self-reported smoking habits is often questioned but the development of biochemical assays that measure the nicotine metabolite cotinine, allow for an objective assessment of smoking status. Here we assess the accuracy of self-reported smoking habits in patients with tuberculosis by comparing these with urinary cotinine levels. Methods Patients were recruited from two London tuberculosis clinics. Self-reported smoking habits were obtained from an interviewer administered questionnaire. Urinary cotinine levels were measured using a SmokeScreen ® test kit (GFC Diagnostics, Oxfordshire, UK), a semi-quantitative colorimetric assay. Results One hundred patients attending clinic for treatment of active tuberculosis or latent tuberculosis infection completed the study (Table 1). Nineteen reported using tobacco and had either smoked or chewed tobacco the day before testing, the quantity of which was representative of a standard day’s consumption. Duration of smoking ranged from 3 to 40 years with a mean of 13.4+10.5 and a median of 10.0. Eight further patients recorded stopping smoking between a few days and 6 years prior to testing, with a mean cessation period of 2.0+2.1 years. Two of these had later started chewing tobacco. Although nineteen patients reported either smoking or chewing tobacco, a further six patients’ urine tested positive for cotinine, i.e. 24% of tobacco users failed to report its use (Table 1). Furthermore, nine patients produced the colour change indicating heavy smoking (11–15/day) and ten patients produced a result indicating very heavy smoking (>16/day), although only two reported smoking 11–15 cigarettes the previous day and a further two must have chewed an equivalent amount of tobacco. This corresponds to 79% of heavy to very heavy tobacco users under-reporting its use. Conclusion Discrepancies exist between objective and subjective assessments of smoking habits amongst patients with TB which may be attributable to an under-reporting of tobacco use, suggesting further avenues of research in this patient cohort.

Diagnosing abdominal tuberculosis in the acute abdomen

BackgroundDespite recent improvements in medical treatments, the incidence of abdominal tuberculosis (ATB) in the United Kingdom has increased over the past two decades. This case series examined the difficulties encountered in correctly diagnosing this infection. Patients and methodsA retrospective study was undertaken, reviewing the records of 36 patients diagnosed with ATB from 2000 to 2012 at a district general hospital in outer East London. ResultsThe commonest presenting feature was abdominal pain in 67% of patients, and the most common sites of infection were the iliocaecal junction and peritoneum, seen in 36.1% and 33.3% respectively. Six patients were initially investigated for Crohn's disease and one for ileitis. The highest disease prevalence was seen in patients born in India and Pakistan, which was 27.8% and 19.4% of patients respectively.Colonoscopy was performed in nine patients, and three of these reported normal findings. The other six reported visible non-specific inflammatory changes. Three patients had abdominal X-rays reported and one patient had an abdominal ultrasound, all of which were normal. An abdominal computerised topography (CT) scan was performed in 26 patients and a chest CT was undertaken in 19 patients. Varying degrees of inflammatory changes were seen in all of the patients who had CT scans. Microbiological culture was positive for Mycobacterium tuberculosis or acid-fast bacilli in 71% of patients. ConclusionsAbdominal tuberculosis can be very difficult to diagnose as symptoms are non-specific and can mimic other types of granulomatous inflammatory bowel diseases. Radiology appears largely unhelpful due to the non-specificity of any positive imaging findings, and there is a lack of diagnostic procedural and microbiological tests with high specificity and sensitivity. In view of the increasing incidence of tuberculosis in London, there should be a high index of suspicion for ATB in individuals from high-incidence countries who present with non-specific abdominal symptoms.