Metabolic and Bariatric Surgery in Patients with Obesity Class V (BMI > 60 kg/m2): a Modified Delphi Study

BACKGROUND

Metabolic and bariatric surgery (MBS) is the preferred method to achieve significant weight loss in patients with Obesity Class V (BMI > 60 kg/m2). However, there is no consensus regarding the best procedure(s) for this population. Additionally, these patients will likely have a higher risk of complications and mortality. The aim of this study was to achieve a consensus among a global panel of expert bariatric surgeons using a modified Delphi methodology.

METHODS

A total of 36 recognized opinion-makers and highly experienced metabolic and bariatric surgeons participated in the present Delphi consensus. 81 statements on preoperative management, selection of the procedure, perioperative management, weight loss parameters, follow-up, and metabolic outcomes were voted on in two rounds. A consensus was considered reached when an agreement of ≥ 70% of experts' votes was achieved.

RESULTS

A total of 54 out of 81 statements reached consensus. Remarkably, more than 90% of the experts agreed that patients should be notified of the greater risk of complications, the possibility of modifications to the surgical procedure, and the early start of chemical thromboprophylaxis. Regarding the choice of the procedure, SADI-S, RYGB, and OAGB were the top 3 preferred operations. However, no consensus was reached on the limb length in these operations.

CONCLUSION

This study represents the first attempt to reach consensus on the choice of procedures as well as perioperative management in patients with obesity class V. Although overall consensus was reached in different areas, more research is needed to better serve this high-risk population.

Performance evaluation of human cough annotators: optimal metrics and sex differences

INTRODUCTION

Despite its high prevalence and significance, there is still no widely available method to quantify cough. In order to demonstrate agreement with the current gold standard of human annotation, emerging automated techniques require a robust, reproducible approach to annotation. We describe the extent to which a human annotator of cough sounds (a) agrees with herself (intralabeller or intrarater agreement) and (b) agrees with other independent labellers (interlabeller or inter-rater agreement); we go on to describe significant sex differences in cough sound length and epochs size.

MATERIALS AND METHODS

24 participants wore an audiorecording smartwatch to capture 6-24 hours of continuous audio. A randomly selected sample of the whole audio was labelled twice by an expert annotator and a third time by six trained annotators. We collected 400 hours of audio and analysed 40 hours. The cough counts as well as cough seconds (any 1 s of time containing at least one cough) from different annotators were compared and summary statistics from linear and Bland-Altman analyses were used to quantify intraobserver and interobserver agreement.

RESULTS

There was excellent intralabeller (less than two disagreements per hour monitored, Pearson's correlation 0.98) and interlabeller agreement (Pearson's correlation 0.96), using cough seconds as the unit of analysis decreased annotator discrepancies by 50% in comparison to coughs. Within this data set, it was observed that the length of cough sounds and epoch size (number of coughs per bout or attach) differed between women and men.

CONCLUSION

Given the decreased interobserver variability in annotation when using cough seconds (vs just coughs) we propose their use for manually annotating cough when assessing of the performance of automatic cough monitoring systems. The differences in cough sound length and epochs size may have important implications for equality in the development of cough monitoring tools.

TRIAL REGISTRATION NUMBER

NCT05042063.

A Contemporary Review of Smart Phone Applications in Bariatric and Metabolic Surgery: an Underdeveloped Support Service

This study aims to be a contemporary review of mHealth apps in bariatric and metabolic surgery (BMS) to assess their quality using the Silberg scale as well as features, themes, usability, and medical/allied health professional involvement (MAPI). Apps were identified using search terms in the Android and Apple app stores. 52 apps were included. 42 (80.7%) apps main target users were patients. More than half, 27 (52%), targeted US based users. 29 (56%) had payment-restricted content. 42 (81%) had MAPI and the mean Silberg score was 5.2. Compared to previous studies the quality of BMS apps is improving with more MAPI and useful functionality. Wider use of mHealth apps for patient centred follow-up, management and care are yet to be widely implemented and explored.

Acoustic surveillance of cough for detecting respiratory disease using artificial intelligence

Research question

Can smartphones be used to detect individual and population-level changes in cough frequency that correlate with the incidence of coronavirus disease 2019 (COVID-19) and other respiratory infections?

Methods

This was a prospective cohort study carried out in Pamplona (Spain) between 2020 and 2021 using artificial intelligence cough detection software. Changes in cough frequency around the time of medical consultation were evaluated using a randomisation routine; significance was tested by comparing the distribution of cough frequencies to that obtained from a model of no difference. The correlation between changes of cough frequency and COVID-19 incidence was studied using an autoregressive moving average analysis, and its strength determined by calculating its autocorrelation function (ACF). Predictors for the regular use of the system were studied using a linear regression. Overall user experience was evaluated using a satisfaction questionnaire and through focused group discussions.

Results

We followed-up 616 participants and collected >62 000 coughs. Coughs per hour surged around the time cohort subjects sought medical care (difference +0.77 coughs·h−1; p=0.00001). There was a weak temporal correlation between aggregated coughs and the incidence of COVID-19 in the local population (ACF 0.43). Technical issues affected uptake and regular use of the system.

Interpretation

Artificial intelligence systems can detect changes in cough frequency that temporarily correlate with the onset of clinical disease at the individual level. A clearer correlation with population-level COVID-19 incidence, or other respiratory conditions, could be achieved with better penetration and compliance with cough monitoring.

Longitudinal Passive Cough Monitoring and Its Implications for Detecting Changes in Clinical Status

Research Question

What is the impact of the duration of cough monitoring on its accuracy in detecting changes in the cough frequency?

Materials and Methods

This is a statistical analysis of a prospective cohort study. Participants were recruited in the city of Pamplona (Northern Spain) and their cough frequency was passively monitored using smartphone-based acoustic artificial intelligence software. Differences in cough frequency were compared using a one-tailed Mann-Whitney U test and a randomisation routine to simulate 24-h monitoring.

Results

616 participants were monitored for an aggregated duration of over 9 person-years and registered 62 325 coughs. This empiric analysis found that an individual's cough patterns are stochastic, following a binomial distribution. When compared to continuous monitoring, limiting observation to 24 h can lead to inaccurate estimates of change in cough frequency, particularly in persons with low or small changes in rate.

Interpretation

Detecting changes in an individual's rate of coughing is complicated by significant stochastic variability within and between days. Assessing change based solely on intermittent sampling, including 24-h, can be misleading. This is particularly problematic in detecting small changes in individuals who have a low rate and/or high variance in cough pattern.

Routine Use of Esophago-gastro-duodenoscopy (EGD) in Bariatric Surgery-an International Survey of Our Current Practice

INTRODUCTION

The role of esophago-gastro-duodenoscopy (EGD) in bariatric surgery has been widely discussed. In 2020, the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) issued recommendations on the routine use of EGD before and after bariatric surgery. However, little is known of our current practice and the guidance uptake.

METHODS

We conducted an international survey assessing bariatric surgeons' practice on the use of EGD. The survey aimed to identify whether surgeons offer EGD in the following settings: pre-operative, post-operative at 1 year, every 2-3 years following longitudinal sleeve gastrectomy (LSG) or one-anastomosis gastric bypass (OAGB). Data was analyzed using descriptive statistics.

RESULTS

Among 121 respondents, 72% are aware of the IFSO recommendations. The commonly performed bariatric procedures were LSG, Roux-en-Y gastric bypass (RYGB), and OAGB. 53.7% surgeons routinely offer pre-operative EGD and 14.3% routinely offer post-operative EGD for bariatric patients at 1 year after surgery. Majority do not routinely offer EGD after LSG (74.8%) or OAGB (79.7%) every 2-3 years as proposed by IFSO.

CONCLUSION

The uptake of IFSO recommendation is variable according to each recommendation with better compliance among surgeons with regard to pre-operative EGD. Further research is necessary to develop robust evidence-base for the role of endoscopy after bariatric surgery with the inclusion of patient and public involvement.

Outcomes of bariatric surgery in extreme obesity: results from the United Kingdom National Bariatric Surgery Registry for patients with a body mass index >70 kg/m2

BACKGROUND

Bariatric and metabolic surgery (BMS) is an established safe, effective, and durable treatment for obesity and its complications. However, there is still a paucity of evidence on surgery outcomes in patients suffering from extreme obesity.

OBJECTIVES

This study aimed to evaluate outcomes of BMS in weight loss and the resolution of co-morbidities in patients with a body mass index (BMI) ≥70kg/m2.

SETTING

National Health Service and private hospitals in the United Kingdom.

METHODS

This cohort study analyzed prospectively collected records from the UK National Bariatric Surgery Registry of patients with a BMI ≥70 kg/m2 undergoing Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), or adjustable gastric band (AGB) between January 2009 and June 2014.

RESULTS

There were 230 patients (64% female) eligible for inclusion in the study: 22 underwent AGB; 102 underwent SG, and 106 underwent RYGB. Preoperative weight and BMI values were comparable (76 ± 7 kg/m2 for AGB; 75 ± 5 kg/m2 for SG; 74 ± 5 kg/m2 for RYGB). The median postoperative follow-up was 13 months for AGB (10-22 mo), 18 for SG (6-28 mo), and 15 for RYGB (6-24 mo). Patients undergoing RYGB and SG exhibited the greatest postoperative total body weight loss (35 ± 13% and 31 ± 15%, respectively; P = .14), which led to postoperative BMIs of 48 ± 10 kg/m2 and 51 ± 11 kg/m2, respectively (P = .14). All procedures conferred a reduction in the incidence of co-morbidities, including type 2 diabetes, and led to improved functional statuses. The overall complication rate was 7%, with 3 deaths (1%) within 30 days of surgery.

CONCLUSION

This study found that primary BMS in patients with a BMI >70kg/m2 has an acceptable safety profile and is associated with good medium-term clinical outcomes. RYGB and SG are associated with better weight loss and great improvements in co-morbidities than AGB. Given the noninferiority of SG outcomes and SG's potential for further conversion to other BMS procedures if required, SG may be the best choice for primary BMS in patients with extreme obesity.

Obstructive sleep apnea remission following bariatric surgery: a national registry cohort study

BACKGROUND

Obstructive sleep apnea (OSA) is strongly associated with metabolic syndrome. Bariatric surgery is an effective available treatment for OSA; however, limited research predicts which patients undergoing bariatric surgery will undergo OSA resolution.

OBJECTIVES

To determine perioperative predictors for OSA resolution following bariatric surgery using a national database.

SETTING

United Kingdom national bariatric surgery database.

METHODS

The UK National Bariatric Surgery Registry (NBSR) was interrogated to identify all patients with OSA that underwent primary bariatric surgery between January 2009 and June 2017. Those with at least 1 follow-up recording postoperative OSA status were selected for further analysis. Demographic, pre- and postoperative outcomes were collected and analyzed. Poisson multivariate regression was conducted to identify predictors of OSA remission.

RESULTS

A total of 4015 bariatric cases were eligible for inclusion: 2482 (61.8%) patients underwent laparoscopic Roux-en-Y gastric bypass (LRYGB), 1196 (29.8%) sleeve gastrectomy (LSG), and 337 (8.4%) adjustable gastric banding (LAGB). Overall, the mean excess weight loss (EWL) % for the whole group was 61.2 (SD ± 27.2). OSA resolution was recorded in 2377 (59.2%) patients. Following Poisson regression, LRYGB (risk ratio [RR], 1.49 confidence interval [CI] 1.25-1.78) and LSG (RR, 1.46 [CI 1.22-1.75] were associated with approximately 50% increased likelihood of OSA remission compared with LAGB. Greater weight loss following intervention was associated with greater likelihood of OSA remission, while both greater age and greater preoperative body mass index (BMI) were associated with reduced likelihood of OSA remission (P < .001).

CONCLUSION

This study demonstrated that metabolic surgery results in OSA remission in the majority of patients with obesity. Younger age, lower BMI preprocedure, greater %EWL and the use of LSG or LRYGB positively predicted OSA remission.

Diagnostic Performance of Artificial Intelligence-Based Models for the Detection of Early Esophageal Cancers in Barret's Esophagus: A Meta-Analysis of Patient-Based Studies

Introduction

Barret’s esophagus (BE) is a precursor of adenocarcinoma of the esophagus. The detection of high-grade dysplasia and adenocarcinoma at an early stage can improve survival but is very challenging. Artificial intelligence (AI)-based models have been claimed to improve diagnostic accuracy. The aim of the current study was to carry out a meta-analysis of papers reporting the results of artificial intelligence-based models used in real-time white light endoscopy of patients with BE to detect early esophageal adenocarcinoma (EEAC).

Methods

This meta-analysis was registered with the International Prospective Register of Systematic Reviews (PROSPERO; Reg No. CRD42021246148) and its conduction and reporting followed the Preferred Reporting Items for Systematic Review and Meta-Analysis of Diagnostic Test Accuracy (PRISMA-DTA) statement guidelines. All peer-reviewed and preprint original articles that reported the sensitivity and specificity of AI-based models on white light endoscopic imaging as an index test against the standard criterion of histologically proven early oesophageal cancer on the background of Barret's esophagus reported as per-patient analysis were considered for inclusion. There was no restriction on type and year of publication, however, articles published in the English language were searched. The search engines used included Medline, PubMed, EMBASE, EMCARE, AMED, BNI, and HMIC. The search strategy included the following keywords for all search engines: ("Esophageal Cancer" OR "Esophageal Neoplasms" OR " Oesophageal Cancer" OR "Oesophageal Neoplasms” OR "Barrett's Esophagus" OR "Barrett's Oesophagus") And ("Artificial Intelligence" OR "Deep Learning" OR "Machine Learning" OR "Convolutional Network"). This search was conducted on November 30, 2020. Duplicate studies were excluded. Studies that reported more than one dataset per patient for the diagnostic accuracy of the AI-based model were included twice. Quantitative and qualitative data, including first author, year of publication, true positives (TP), false negatives (FN), false positives (FP), true negatives (TN), the threshold of the index test, and country where the study was conducted, were extracted using a data extraction sheet. The Quality Appraisal for Diverse Studies 2 (QUADS-2) tool was used to assess the quality of each study. Data were analyzed using MetaDTA, interactive online software for meta-analysis of diagnostic studies. The diagnostic performance of the meta-analysis was assessed by a summary receiver operating characteristics (sROC) plot. A meta-analysis tree was constructed using MetaDTA software to determine the effect of cumulative sensitivity and specificity on surveillance of patients with BE in terms of miss rate and overdiagnosis.

Results

The literature search revealed 171 relevant records. After removing duplicates, 117 records were screened. Full-text articles of 28 studies were assessed for eligibility. Only three studies reporting four datasets met the inclusion criteria. The summary sensitivity and specificity of AI-based models were 0.90 (95% CI, 0.83- 0.944) and 0.86 (95% CI, 0.781-0.91), respectively. The area under the curve for all the available evidence was 0.88.

Conclusion

Collective evidence for the routine usage of AI-based models in the detection of EEAC is encouraging but is limited by the low number of studies. Further prospective studies reporting the patient-based diagnostic accuracy of such models are required.

Bariatric surgery for patients with type 2 diabetes mellitus requiring insulin: Clinical outcome and cost-effectiveness analyses

BACKGROUND

Although bariatric surgery is well established as an effective treatment for patients with obesity and type 2 diabetes mellitus (T2DM), there exists reluctance to increase its availability for patients with severe T2DM. The aims of this study were to examine the impact of bariatric surgery on T2DM resolution in patients with obesity and T2DM requiring insulin (T2DM-Ins) using data from a national database and to develop a health economic model to evaluate the cost-effectiveness of surgery in this cohort when compared to best medical treatment (BMT).

METHODS AND FINDINGS

Clinical data from the National Bariatric Surgical Registry (NBSR), a comprehensive database of bariatric surgery in the United Kingdom, were extracted to analyse outcomes of patients with obesity and T2DM-Ins who underwent primary bariatric surgery between 2009 and 2017. Outcomes for this group were combined with data sourced from a comprehensive literature review in order to develop a state-transition microsimulation model to evaluate cost-effectiveness of bariatric surgery versus BMT for patients over a 5-year time horizon. The main outcome measure for the clinical study was insulin cessation at 1-year post-surgery: relative risks (RR) summarising predictive factors were determined, unadjusted, and after adjusting for variables including age, initial body mass index (BMI), duration of T2DM, and weight loss. Main outcome measures for the economic evaluation were total costs, total quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) at willingness-to-pay threshold of GBP£20,000. A total of 2,484 patients were eligible for inclusion, of which 1,847 had 1-year follow-up data (mean age of 51 years, mean initial BMI 47.2 kg/m2, and 64% female). 67% of patients no longer required insulin at 1-year postoperatively: these rates persisted for 4 years. Roux-en-Y gastric bypass (RYGB) was associated with a higher rate of insulin cessation (71.7%) than sleeve gastrectomy (SG; 64.5%; RR 0.92, confidence interval (CI) 0.86-0.99) and adjustable gastric band (AGB; 33.6%; RR 0.45, CI 0.34-0.60; p < 0.001). When adjusted for percentage total weight loss and demographic variables, insulin cessation following surgery was comparable for RYGB and SG (RR 0.97, CI 0.90-1.04), with AGB having the lowest cessation rates (RR 0.55, CI 0.40-0.74; p < 0.001). Over 5 years, bariatric surgery was cost saving compared to BMT (total cost GBP£22,057 versus GBP£26,286 respectively, incremental difference GBP£4,229). This was due to lower treatment costs as well as reduced diabetes-related complications costs and increased health benefits. Limitations of this study include loss to follow-up of patients within the NBSR dataset and that the time horizon for the economic analysis is limited to 5 years. In addition, the study reflects current medical and surgical treatment regimens for this cohort of patients, which may change.

CONCLUSIONS

In this study, we observed that in patients with obesity and T2DM-Ins, bariatric surgery was associated with high rates of postoperative cessation of insulin therapy, which is, in turn, a major driver of overall reductions in direct healthcare cost. Our findings suggest that a strategy utilising bariatric surgery for patients with obesity and T2DM-Ins is cost saving to the national healthcare provider (National Health Service (NHS)) over a 5-year time horizon.

A modified AUGIS Delphi process to establish research priorities in bariatric and metabolic surgery

Delphi methodology may be utilized to develop consensus opinion among a group of experts. The aim of our study was to use a modified Delphi process to determine the future research priorities among bariatric and metabolic healthcare professionals in the United Kingdom. Members of the Association of Upper Gastrointestinal Surgeons and the British Obesity and Metabolic Surgery Society were invited to submit individual research questions via an online survey (phase I). Two rounds of prioritization by multidisciplinary expert healthcare professionals (phase II and III) were completed to determine a final list of high-priority research questions. Fifty-one bariatric and metabolic surgery-focused questions were identified in phase I. Thirty-five questions were taken forward for prioritization in phase II. Eleven high-priority questions were identified in phase III. The final list of high-priority questions had an emphasis on the pathophysiology and long-term sequelae of bariatric and metabolic surgery. A modified Delphi process has produced a list of 11 high-priority research questions in bariatric and metabolic surgery. Future studies and awards from funding bodies should reflect this consensus list of prioritized questions in the interest of improving patient care and encouraging collaborative research across multiple centres.

Initiative for Promoting Affordable and Quality Tuberculosis Tests (IPAQT): a market-shaping intervention in India

A majority of patients with tuberculosis (TB) in India are diagnosed and treated in the private sector. Yet, most private providers do not use most recent WHO-endorsed microbiological tests such as liquid cultures, line probe assays and Xpert MTB/RIF due to a combination of factors such as lack of awareness, misaligned incentives and high prices that are unaffordable for patients. We designed a market-based approach to transform a high-price, low-volume market equilibrium into a low-price, high-volume equilibrium to improve the uptake of these tests. Toward this end, a non-profit consortium of private laboratories, called Initiative for Promoting Affordable and Quality Tuberculosis Tests (IPAQT) was formed in India in March 2013. It negotiated lower pricing on equipment and reagents with manufacturers, closer to that offered to the public sector. In return, IPAQT assured that this discount was passed on to patients, who typically paid for these tests out of their pockets, through an informally agreed on retail ceiling price. IPAQT also invested in demand generation activities that complemented the supply-side effort. IPAQT membership grew from 56 laboratories in 2013 to 211 in 2018. During this period, the initiative resulted in a 10-fold increase in the uptake of Xpert and a 30%-50% reduction in price. This initiative is planned to be expanded to other South Asian countries with similar TB epidemic and private market structure and dynamics. However, long-term sustainability of the initiative would require developing more cost-effective marketing activities and integration with broader private sector engagement agenda of the national TB programme.

Epidemiology of soil transmitted helminth and Strongyloides stercoralis infections in remote rural villages of Ranomafana National Park, Madagascar

Soil-transmitted helminth (STH) infections carry the highest number of disability adjusted life years among all neglected tropical diseases, disproportionately affecting low-income countries such as Madagascar.  This study describes the epidemiology of STH and S. stercoralis infections in twelve remote villages surrounding Ranomafana National Park (RNP), Ifanadiana, Madagascar. Questionnaires and stool samples were collected from 574 subjects from random households. The Kato-Katz method and spontaneous sedimentation technique were used to examine stool samples for evidence of infection. Infection prevalence rates were 71.4% for Ascaris lumbricoides (95% CI: 67.7-75.1), 74.7% for Trichuris trichiura (95% CI: 71.1-78.2), 33.1% for hookworm (95% CI: 29.2-36.9), and 3.3% for Strongyloides stercoralis (95% CI: 1.84-4.77). Participants who were older in age (OR = 0.96; 95% CI: 0.95-0.99) and who had a high school education (OR = 0.17; 95% CI: 0.04-0.77) were less likely to be infected with a STH. Females were less likely to be infected with A. lumbricoides (OR = 0.52; 95% CI: 0.33-0.82). Participants living in villages further from the main road were more likely to be infected with a STH (F = 4.00, p = 0.02). Overall, this study found that 92.5% (95% CI: 90.3-94.6) of the people living in rural regions near RNP have at least one STH infection. This calls into question the current preventative chemotherapy (PC) program in place and suggests that further medical, socioeconomic, and infrastructural deveopments are needed to reduce STH prevalence rates among this underserved population.

450. Using Geographical Information Systems to Interpret the Efficacy of Mass Drug Administration for Soil-Transmitted Helminthiasis in Rural Madagascar

Background

In Madagascar, mass drug administration (MDA) of anti-parasitics is administered every 6 months to combat soil-transmitted helminthiasis (STH) in school-aged children, although little information exists as to its efficacy. In recent years, geographical information systems (GIS) have been used for visualization of patterns in disease epidemiology. This inexpensive technology may be leveraged to aid in education of local health workers toward a more integrated approach to control STH.

Methods

Baseline questionnaires and stool/blood samples were collected from participants of Mangevo, a rural village in southeast Madagascar. GPS coordinates and qualitative descriptions were collected from all village homes, common latrines, and animal pens. All children 5–15 years old were given MDA per WHO protocol. Stool was again collected from these children 2 weeks later and 3 months later. Parasitological examination of stool samples for STH eggs was performed using Spontaneous Sedimentation Technique. Results were overlaid onto GIS maps and used to further educate the local mobile health team.

Results

A total of 183 participants were eligible for the study. Analysis found 89% of adults >15 years old were infected with one or more parasite and 100% of children 5–15 were infected with one or more parasite at time 0. Trichuris trichuria prevalence fell 8% (P < 0.5) in 2 weeks and climbed 17% (P < 0.05) by 3 months follow-up. Ascaris lumbricoides prevalence fell 96% (P < 0.0001) in the 2 weeks and climbed 95% (P < 0.0001) by 3 months follow-up. Hookworm prevalence dropped 89% (P < 0.0001) in 2 weeks and climbed 5% (P < 0.5) by 3 months follow-up. Prevalence data, descriptive results, and GPS coordinates of village homes were integrated into a GIS maps pre- and post-MDA of children, and pre-MDA for adults.

Conclusion

While GIS has been used to yield insights into the ecology of infection, this study examined the efficacy of the current MDA through the lens of small scale GIS mapping. This may be an ideal and inexpensive technology to help in the implementation of future interventions of the government-mandated STH treatment protocol and work toward the strengthening of local health teams.

Disclosures

All authors: No reported disclosures.

Allergic rhinitis

Allergic rhinitis is a common disorder that is strongly linked to asthma and conjunctivitis. It is usually a long-standing condition that often goes undetected in the primary-care setting. The classic symptoms of the disorder are nasal congestion, nasal itch, rhinorrhea and sneezing. A thorough history, physical examination and allergen skin testing are important for establishing the diagnosis of allergic rhinitis. Second-generation oral antihistamines and intranasal corticosteroids are the mainstay of treatment. Allergen immunotherapy is an effective immune-modulating treatment that should be recommended if pharmacologic therapy for allergic rhinitis is not effective or is not tolerated, or if chosen by the patient. This article provides an overview of the pathophysiology, diagnosis, and appropriate management of this disorder.

The Effects of Allergen-Induced Nasal Provocation on Pulmonary Function in Patients with Perennial Allergic Rhinitis

Fifteen patients with perennial allergic rhinitis responded intranasally to ragweed antigen challenge. Concomitant measurements of pulmonary function did not reveal a significant decrement on flow rates over a 30-minute period.

Obesity surgery makes patients healthier and more functional: real world results from the United Kingdom National Bariatric Surgery Registry

BACKGROUND

The National Bariatric Surgery Registry (NBSR) is the largest bespoke database in the field in the United Kingdom.

OBJECTIVES

Our aim was to analyze the NBSR to determine whether the effects of obesity surgery on associated co-morbidities observed in small randomized controlled clinical trials could be replicated in a "real life" setting within U.K. healthcare.

SETTING

United Kingdom.

METHODS

All NBSR entries for operations between 2000 and 2015 with associated demographic and co-morbidity data were analyzed retrospectively.

RESULTS

A total of 50,782 entries were analyzed. The patients were predominantly female (78%) and white European with a mean age of 45 ± 11 years and a mean body mass index of 48 ± 8 kg/m². Over 5 years of follow-up, statistically significant reductions in the prevalence of type 2 diabetes, hypertension, dyslipidemia, sleep apnea, asthma, functional impairment, arthritis, and gastroesophageal reflux disease were observed. The "remission" of these co-morbidities was evident 1 year postoperatively and reached a plateau 2 to 5 years after surgery. Obesity surgery was particularly effective on functional impairment and diabetes, almost doubling the proportion of patients able to climb 3 flights of stairs and halving the proportion of patients with diabetes related hyperglycemia compared with preoperatively. Surgery was safe with a morbidity of 3.1% and in-hospital mortality of .07% and a reduced median inpatient stay of 2 days, despite an increasingly sick patient population.

CONCLUSIONS

Obesity surgery in the U.K. results not only in weight loss, but also in substantial improvements in obesity-related co-morbidities. Appropriate support and funding will help improve the quality of the NBSR data set even further, thus enabling its use to inform healthcare policy.

Disparities in rate, triggers, and management in pediatric and adult cases of suspected drug-induced anaphylaxis in Canada

INTRODUCTION

Data is sparse on drug-induced anaphylaxis (DIA) and there have not been studies assessing the differences in clinical characteristics and management of DIA between adults and children.

OBJECTIVE

We assessed the percentage, diagnosis, and management of DIA among all anaphylaxis visits in three pediatric and one adult emergency departments (ED) across Canada.

METHODS

Children presenting to the Montreal Children's Hospital (MCH), British Columbia Children's Hospital (BCCH), and Children's Hospital at London Health Sciences Center and adults presenting to Hôpital du Sacré-Coeur with anaphylaxis were recruited as part of the Cross-Canada Anaphylaxis Registry. A standardized data form documenting the reaction and management was completed and patients were followed annually to determine assessment by allergist and use of confirmatory tests.

RESULTS

From June 2012 to May 2016, 51 children were recruited from the pediatric centers and 64 adults from the adult center with drug-induced anaphyalxis. More than half the cases were prospectively recruited. The percentage of DIA among all cases of anaphylaxis was similar in all three pediatric centers but higher in the adult center in Montreal. Most reactions in children were triggered by non-antibiotic drugs, and in adults, by antibiotics. The majority of adults and a third of children did not see an allergist after the initial reaction. In those that did see an allergist, diagnosis was established by either a skin test or an oral challenge in less than 20% of cases.

CONCLUSIONS

Our results reveal disparities in rate, culprit, and management of DIA in children versus adults. Further, most cases of suspected drug allergy are not appropriately diagnosed. Guidelines to improve assessment and diagnosis of DIA are required.

Mortality related to primary bariatric surgery in England

Background

Bariatric surgery is an accepted treatment option for severe obesity. Previous analysis of the independently collected Hospital Episode Statistics (HES) data for outcomes after bariatric surgery demonstrated a 30‐day postoperative mortality rate of 0·3 per cent in the English National Health Service (NHS). However, there have been no published mortality data for bariatric procedures performed since 2008. This study aimed to assess mortality related to bariatric surgery in England from 2009.

Methods

HES data were used to identify all patients who had primary bariatric surgery from 2009 to 2016. Clinical codes were used selectively to identify all primary bariatric procedures but exclude revision or conversion procedures and operations for malignant or other benign disease. The primary outcome measures were HES in‐hospital and Office for National Statistics (ONS) 30‐day mortality after discharge.

Results

A total of 41 241 primary bariatric procedures were carried out in the NHS between 2009 and 2016, with 29 in‐hospital deaths (0·07 per cent). The 30‐day mortality rate after discharge was 0·08 per cent (32 of 41 241). Both the in‐hospital and 30‐day mortality rates after discharge demonstrated a downward trend over the study period.

Conclusion

Overall in‐hospital and 30‐day mortality rates remain very low after primary bariatric surgery. An increased uptake of bariatric surgery within the English NHS has been safe.

Suppurative appendicitis presenting as acute scrotum confounded by a testicular appendage

Patients presenting with testicular pain and swelling mandate an urgent urology review and scrotal exploration to prevent testicle loss due to torsion. Other pathology masquerading as torsion is extremely rare but can occur. We present one such case. A 14-year-old male presented with a 1-day history of right testicular swelling and tenderness. He was apyrexial and denied any other symptoms. Blood tests demonstrated raised inflammatory markers. He had lower left-sided abdominal tenderness with a swollen, erythematous right hemiscrotum. During an urgent scrotal exploration for testicular torsion, a purulent hydrocele with a patent process vaginalis was noted, but no torsion. Post-operative abdominal pain mandated a general surgical review and subsequent appendicectomy. The patient made a full recovery. Acute suppurative appendicitis presenting as a urological emergency is extremely rare. To make a correct diagnosis and prevent multiple surgeries, a joint urological and general surgical assessment with a high index of suspicion is required.

Transcriptional profiles discriminate patients with pulmonary tuberculosis from non-tuberculous individuals depending on the presence of non-insulin diabetes mellitus

Our objective was to identify transcriptional biomarkers in peripheral blood mononuclear cells (PBMC) that discriminate individuals with latent tuberculosis infection (LTBI) from those with pulmonary tuberculosis (PTB) in subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in individuals without NIDDM. Using gene expression microarrays we identified differentially expressed genes from lungs of mice infected with Mycobacterium tuberculosis (Mtb) or a mutant (ΔsigH) representing a non-inflammatory model. Genes expressed in blood, with inflammatory related functions were evaluated in humans by RT-qPCR. NCF1 and ORM transcripts have the better discriminatory capacity to identify PTB subjects from LTBI and non-infected controls (NICs) independently of the presence of NIDDM. The sequential evaluation of the mRNA levels of NCF1 and ORM as multiple diagnostic tests showed 95% Sensitivity (Se) and 80% Specificity (Sp). In addition, FPR2 promises to be a good biomarker for the PTB detection in subjects with NIDDM (Se=100%; Sp=90%).

The relationship of distance from the surgical centre on attendance and weight loss after laparoscopic gastric bypass surgery in the United Kingdom

Obesity remains a significant worldwide health problem and is currently increasing. Surgery remains the only proven long-term intervention and has been shown to be cost-effective. Evidence suggests that regular follow-up following laparoscopic adjustable gastric banding is related to improved outcome, such evidence is lacking for laparoscopic gastric bypass surgery (laparoscopic Roux-en-Y gastric bypass [LRYGB]). This study examines the effect of distance on attendance at post-operative clinics and subsequent weight loss following surgery. A prospectively maintained database was interrogated to analyze patients undergoing LRYGB before August 2010. Patient demographics, percentage excess weight loss (%EWL), compliance with out-patient clinic attendances and the distance the patients lived from the hospital were examined. Perfect clinic attendees were compared with non-attendees and the distances patients lived from the hospital evaluated. There was a significantly greater %EWL at 1 year post-op observed in the perfect attendees group (65.5 vs. 59.5, P = 0.01). Increased %EWL was also evident at 2 years post-op but did not reach statistical significance (66.9 vs. 59.5, P = 0.06). There was a negative correlation observed between post-operative weight loss and distance from the bariatric centre (R = -0.21, P = 0.04). Close follow-up following LRYGB is essential to optimize outcomes. Increased frequency of out-patient clinic visits was associated with improved post-operative weight loss. Increasing distance between the patient's home and the bariatric centre was associated with worse post-operative weight loss.

Routine group and save unnecessary for gastric band surgery: a retrospective case review audit of 1018 bariatric patients

What is already known about this subject •  The demand for bariatric surgery is increasing. •  NHS Trusts are expected to instigate cost-efficiency measures. •  Previous articles have discussed the need for routine preoperative cross-match. What this study adds •  No gastric band patient suffered a significant drop in haemoglobin or needed a blood transfusion. •  Group and save samples could be safely stored in the laboratory and only sent for analysis if clinically indicated. •  Even greater cost savings could be achieved if prudent use of perioperative blood testing and blood transfusion was implemented.

SUMMARY

Current guidance at our Trust is that all bariatric surgical patients should have preoperative group and save (G&S) and full blood count (FBC) tests, as well as a FBC check 1 d post-operatively. Our aim was to investigate blood transfusion requirements of these patients and whether we could reduce the number of investigations requested. 1018 consecutive elective laparoscopic gastric band and laparoscopic Roux-en-Y gastric bypass patients who were operated on in our bariatric unit from March 2000 until January 2011 were identified. Patients' haemoglobin levels, G&S status and blood transfusion requirements were analyzed using our online pathology system. 607 patients had a laparoscopic gastric band, with 411 undergoing a laparoscopic Roux-en-Y gastric bypass. None of our gastric band patients required a transfusion; however, nine patients (2.2%) undergoing a gastric bypass needed a transfusion. Two patients required transfusion within 24 h of surgery while six of the remaining seven patients received blood 3-4 d post-operatively. Costs incurred on FBC and G&S tests during this time were estimated to exceed £15 700. G&S and post-operative FBC tests could be abandoned for laparoscopic gastric band patients with significant financial and person-time savings. However, given that 2.2% of laparoscopic Roux-en-Y gastric bypass patients needed a blood transfusion, we believe that post-operative FBC tests are still warranted in this patient group, with a G&S sample stored in pathology. Much greater financial savings could be achieved if prudent use of preoperative investigations, including storing G&S samples in the laboratory, was adopted for all elective operations.

Why India should become a global leader in high-quality, affordable TB diagnostics

The scale up of DOTS in India is one of the greatest public health accomplishments, and yet undiagnosed and poorly managed TB continues to fuel the epidemic such that India continues to have the highest number of TB cases in the world. Recognizing these challenges, the Government of India has set an ambitious goal of providing universal access to quality diagnosis and treatment for all TB patients in the country. Innovative tools and delivery systems in both the public and private sectors are essential for reaching this goal. Fortunately, India has the potential to solve its TB problem with "home-grown" solutions. Just as Indian pharmaceutical companies revolutionized access to high-quality, affordable AIDS drugs through generic production, Indian diagnostic companies could also become the world's hub for high-quality generic diagnostics. In the long term, India has the potential to lead the world in developing innovative TB diagnostics. For this to happen, Indian industry must move from the import and imitation approach to genuine innovation in both product development as well as delivery. This must be supported by permissive policies and enhanced funding by the Indian government and the private sector. Strict regulation of diagnostics, increased attention to quality assurance in laboratories, and greater engagement of the private health care providers are also needed to effectively deliver innovative products and approaches.

Allergic rhinitis

Allergic rhinitis is a common disorder that is strongly linked to asthma and conjunctivitis. It is usually a long-standing condition that often goes undetected in the primary-care setting. The classic symptoms of the disorder are nasal congestion, nasal itch, rhinorrhea and sneezing. A thorough history, physical examination and allergen skin testing are important for establishing the diagnosis of allergic rhinitis. Second-generation oral antihistamines and intranasal corticosteroids are the mainstay of treatment. Allergen immunotherapy is an effective immune-modulating treatment that should be recommended if pharmacologic therapy for allergic rhinitis is not effective or is not tolerated. This article provides an overview of the pathophysiology, diagnosis, and appropriate management of this disorder.

Diagnosing allergic rhinitis: effectiveness of the physical examination in comparison to conventional skin testing

OBJECTIVE

To evaluate the effectiveness of physical examination alone in diagnosing nasal allergic patients.

DESIGN

A cross-sectional study of 15 consecutive evaluable patients.

SETTING

A tertiary care otolaryngology clinic at the Jewish General Hospital, McGill University, Montreal.

METHODS

All patients were assessed by three physicians in random order. Each conducted a specific examination, made a clinical impression, and then took a directed history to make a second impression. Both impressions were compared to skin testing. Multivariate regression analyses assessed the linear relationships of both examination and history variables to impressions and skin testing results. Fleiss kappa tests assessed interrater reliabilities.

MAIN OUTCOME MEASURES

Accuracy in diagnosing allergic rhinitis by examination alone and inter-rater reliability in this diagnosis.

RESULTS

When comparing physical examination variables to history variables relative to the second impression, history variables had a stronger relationship (R²  =  .90 vs .52). This was also true when comparing both sets of variables to skin testing (R²  =  .81 vs .60). The interrater reliability of physical examination variables was poorer than that of the history variables (.377 and .494, respectively). Taking all physicians, the average sensitivity, specificity, positive predictive value, and negative predictive value of the history impression were all higher than those of the examination impression.

CONCLUSION

Physical examination alone yields unreliable and inconsistent results in diagnosing allergic rhinitis. This is likely secondary to the relative subjectivity involved in evaluating the nasal cavity. Adding a history to the examination is essential to increase diagnostic accuracy.

Canadian clinical practice guidelines for acute and chronic rhinosinusitis

This document provides health care practitioners with information regarding the management of acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) to enable them to better meet the needs of this patient population. These guidelines describe controversies in the management of acute bacterial rhinosinusitis (ABRS) and include recommendations that take into account changes in the bacteriologic landscape. Recent guidelines in ABRS have been released by American and European groups as recently as 2007, but these are either limited in their coverage of the subject of CRS, do not follow an evidence-based strategy, or omit relevant stakeholders in the development of guidelines and do not address the particulars of the Canadian health care environment.Advances in understanding the pathophysiology of CRS, along with the development of appropriate therapeutic strategies, have improved outcomes for patients with CRS. CRS now affects large numbers of patients globally, and primary care practitioners are confronted by this disease on a daily basis. Although initially considered a chronic bacterial infection, CRS is now recognized as having multiple distinct components (eg, infection, inflammation), which have led to changes in therapeutic approaches (eg, increased use of corticosteroids). The role of bacteria in the persistence of chronic infections and the roles of surgical and medical management are evolving. Although evidence is limited, guidance for managing patients with CRS would help practitioners less experienced in this area offer rational care. It is no longer reasonable to manage CRS as a prolonged version of ARS, but, rather, specific therapeutic strategies adapted to pathogenesis must be developed and diffused.Guidelines must take into account all available evidence and incorporate these in an unbiased fashion into management recommendations based on the quality of evidence, therapeutic benefit, and risks incurred. This document is focused on readability rather than completeness yet covers relevant information, offers summaries of areas where considerable evidence exists, and provides recommendations with an assessment of the strength of the evidence base and the degree of endorsement by the multidisciplinary expert group preparing the document.These guidelines have been copublished in both Allergy, Asthma, and Clinical Immunology and the Journal of Otolaryngology-Head and Neck Surgery.

Canadian clinical practice guidelines for acute and chronic rhinosinusitis

This document provides healthcare practitioners with information regarding the management of acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) to enable them to better meet the needs of this patient population. These guidelines describe controversies in the management of acute bacterial rhinosinusitis (ABRS) and include recommendations that take into account changes in the bacteriologic landscape. Recent guidelines in ABRS have been released by American and European groups as recently as 2007, but these are either limited in their coverage of the subject of CRS, do not follow an evidence-based strategy, or omit relevant stakeholders in guidelines development, and do not address the particulars of the Canadian healthcare environment.

Advances in understanding the pathophysiology of CRS, along with the development of appropriate therapeutic strategies, have improved outcomes for patients with CRS. CRS now affects large numbers of patients globally and primary care practitioners are confronted by this disease on a daily basis. Although initially considered a chronic bacterial infection, CRS is now recognized as having multiple distinct components (eg, infection, inflammation), which have led to changes in therapeutic approaches (eg, increased use of corticosteroids). The role of bacteria in the persistence of chronic infections, and the roles of surgical and medical management are evolving. Although evidence is limited, guidance for managing patients with CRS would help practitioners less experienced in this area offer rational care. It is no longer reasonable to manage CRS as a prolonged version of ARS, but rather, specific therapeutic strategies adapted to pathogenesis must be developed and diffused.

Guidelines must take into account all available evidence and incorporate these in an unbiased fashion into management recommendations based on the quality of evidence, therapeutic benefit, and risks incurred. This document is focused on readability rather than completeness, yet covers relevant information, offers summaries of areas where considerable evidence exists, and provides recommendations with an assessment of strength of the evidence base and degree of endorsement by the multidisciplinary expert group preparing the document.

These guidelines have been copublished in both Allergy, Asthma & Clinical Immunology and the Journal of Otolaryngology-Head and Neck Surgery.

Management of anaphylaxis in primary care: Canadian expert consensus recommendations

BACKGROUND

Anaphylaxis is often managed inadequately. We used findings from a systematic review of gaps in anaphylaxis management to develop evidence-based recommendations for gaps rated as clinically important by a panel of Canadian allergy experts.

METHODS

The nominal group technique (NGT) consensus methodology was used to develop evidence-based recommendations for the management of anaphylaxis in primary care. Physician-specific gaps from our systematic review were prioritized by consensus meeting participants in two rounds, which involved the rating, discussion, and re-rating of gaps. Using current anaphylaxis guidelines, recommendations were then developed for each category of gaps that were identified by the panel as clinically important.

RESULTS

Thirty unique physician gaps from the systematic review were categorized according to gaps of knowledge and anaphylaxis practice behaviors. The panel rated diagnosis of anaphylaxis, and when and how to use epinephrine auto-injectors as clinically important knowledge gaps; and rated infrequent or delayed epinephrine administration, low rate of auto-injector prescription, and infrequent or no referrals to allergy specialists after a reaction as important practice behavior gaps. Evidence from four guidelines was used to support the consensus recommendation statements for three resulting categories of gap themes: anaphylaxis management, epinephrine use, and follow-up care.

CONCLUSION

We used an NGT consensus methodology to develop an educational resource for primary care physicians and allergists to better understand how to manage patients with anaphylaxis. Next steps include testing our findings against observed data in primary care settings and to develop other strategies or tools to overcome gaps in anaphylaxis management.

Acute appendicitis presenting as small bowel obstruction: two case reports

Acute appendicitis is a common surgical problem however the diagnosis is often overlooked when it presents as a small bowel obstruction. In this report we present two cases of elderly patients who presented with small bowel obstruction and raised inflammatory markers. Both patients were successfully treated with a laparotomy, adhesiolysis and appendicectomy and went on to make a good recovery.

Virulence, immunopathology and transmissibility of selected strains of Mycobacterium tuberculosis in a murine model

After encounter with Mycobacterium tuberculosis, a series of non-uniform immune responses are triggered that define the course of the infection. Eight M. tuberculosis strains were selected from a prospective population-based study of pulmonary tuberculosis patients (1995-2003) based on relevant clinical/epidemiological patterns and tested in a well-characterized BALB/c mouse model of progressive pulmonary tuberculosis. In addition, a new mouse model of transmissibility consisting of prolonged cohousing (up to 60 days) of infected and naïve animals was tested. Four phenotypes were defined based on strain virulence (mouse survival, lung bacillary load and tissue damage), immunology response (cytokine expression determined by real-time polymerase chain reaction) and transmissibility (lung bacillary loads and cutaneous delayed-type hypersensitivity in naïve animals).We identified four clearly defined strain phenotypes: (1) hypervirulent strain with non-protective immune response and highly transmissible; (2) virulent strain, associated with high expression of proinflammatory cytokines (tumour necrosis factor and interferon) and very low anti-inflammatory cytokine expression (interleukins 4 and 10), which induced accelerated death by immunopathology; (3) strain inducing efficient protective immunity with lower virulence, and (4) strain demonstrating strong and early macrophage activation (innate immunity) with delayed participation of acquired immunity (interferon expression). We were able to correlate virulent and transmissible phenotypes in the mouse model and markers of community transmission such as tuberculin reactivity among contacts, rapid progression to disease and cluster status. However, we were not able to find correlation with the other two phenotypes. Our new transmission model supported the hypothesis that among these strains increased virulence was linked to increased transmission.

The influence of host and bacterial genotype on the development of disseminated disease with Mycobacterium tuberculosis

The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated pulmonary tuberculosis. The host genotype of tuberculosis cases was also compared with the genotype of 392 cord blood controls from the same population. Isolates of M. tuberculosis were genotyped by large sequence polymorphisms. The hosts were defined by polymorphisms in genes encoding Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and Toll-like receptor-2 (TLR-2). We found a significant protective association between the Euro-American lineage of M. tuberculosis and pulmonary rather than meningeal tuberculosis (Odds ratio (OR) for causing TBM 0.395, 95% confidence intervals (C.I.) 0.193–0.806, P = 0.009), suggesting these strains are less capable of extra-pulmonary dissemination than others in the study population. We also found that individuals with the C allele of TLR-2 T597C allele were more likely to have tuberculosis caused by the East-Asian/Beijing genotype (OR = 1.57 [95% C.I. 1.15–2.15]) than other individuals. The study provides evidence that M. tuberculosis genotype influences clinical disease phenotype and demonstrates, for the first time, a significant interaction between host and bacterial genotypes and the development of tuberculosis.

Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, kills over 2 million people each year. It is estimated that approximately one-third of the world population is infected with M. tuberculosis, though the majority will never develop active disease. The most severe form of tuberculosis occurs when the bacterium spreads to the brain to cause meningitis. We examined whether the genetic variation of the person and the bacteria influenced the type of disease a person develops. We have previously shown that certain mutations in genes of the human immune system can predispose adults in Vietnam to developing tuberculous meningitis. In this study we show that some strains of M. tuberculosis commonly found in Europe and America are less likely to cause tuberculous meningitis in Vietnamese adults than strains predominantly found in Asia. We then looked at the interaction between M. tuberculosis strains and mutations in human immune genes and show that a particular mutation, TLR2 T597C, is more commonly found in patients infected with the East-Asian/Beijing strains of M. tuberculosis. This is the first study to look at both the host and pathogen genotypes together in tuberculosis infection, and the findings suggest that the outcome of exposure to M. tuberculosis can depend on both the human genotype and the bacterial genotype.

Unique gene expression profiles in infants vaccinated with different strains of Mycobacterium bovis bacille Calmette-Guerin

Vaccination with Mycobacterium bovis bacille Calmette-Guérin (BCG) has variable efficacy in preventing tuberculosis. We hypothesized that some of this variation might be due to differences among BCG strains. To test this, neonates in Orizaba, Mexico, were vaccinated with one of three different BCG strains (BCG-Brazil [BBCG], BCG-Denmark [DBCG], or BCG-Japan [JBCG]). One year after vaccination, peripheral blood mononuclear cells (PBMC) were obtained and recall immune responses to culture filtrate proteins (CFP) of Mycobacterium tuberculosis were evaluated using quantitative real-time PCR. CFP-activated PBMC from BBCG- and DBCG-immunized children expressed high levels of cytokines characteristic of an adaptive immune response (gamma interferon, interleukin-2beta [IL-12beta], and IL-27), while those from children immunized with JBCG did not. In contrast, vaccination with JBCG resulted in significantly greater expression of cytokines characteristic of a proinflammatory immune response (IL-1alpha, IL-1beta, IL-6, and IL-24) in PBMC activated with CFP compared to PBMC from children vaccinated with BBCG or DBCG. Thus, different strains of BCG can activate different immune pathways, which may affect long-term vaccine efficacy.

Is tuberculin skin testing useful to diagnose latent tuberculosis in BCG-vaccinated children?

BACKGROUND

The tuberculin skin test (TST) is the most commonly used tool to detect infection with Mycobacterium tuberculosis. We sought to determine whether tuberculin skin testing is useful to detect latent infection by M. tuberculosis in a population that was vaccinated with the Bacille Calmette Guérin (BCG) vaccine.

METHODS

We performed a cross-sectional study during October 2000-February 2001, enrolling first and sixth graders from a random, stratified sample of public elementary schools in Orizaba, Veracruz, Mexico. We assessed the relationship between sociodemographic and epidemiological information, BCG scars, and TST reactivity.

RESULTS

There were 858 children enrolled in the study with a completed questionnaire and TST result. The prevalence of a positive TST result (> or =10 mm) was 12.4%. Controlling for BCG scar, age, and other characteristics, close contact with pulmonary tuberculosis patients (odds ratio 6.56, 95% confidence interval 2.05-21.07, P = 0.001) was independently associated with TST reactivity.

CONCLUSIONS

TST results helped identify children in a BCG-vaccinated population who had recent exposure to persons with pulmonary tuberculosis, were probably infected with M. tuberculosis, and could benefit from treatment for their latent tuberculosis infection.