Tuberculin reactivity in adults after 50 years of universal bacille Calmette–Guérin vaccination in Taiwan

Diagnosis and Treatment of Tubercular Uveitis in Taiwan - Consensus of Expert Panels

There is currently a lack of guidelines with regard to tubercular uveitis (TBU) management in Taiwan. We therefore propose an evidence-based consensus on the management for TBU. The Taiwan Ocular Inflammation Society conducted a meeting that included nine ophthalmologist and one infection disease expert that focused on three broad areas of (1) nomenclature for TBU, (2) assessment and diagnosis for TBU, and (3) treatment of TBU. Brief literature review on TBU diagnosis and management was conducted that informed this panel meeting in order to make decisions on each consensus statements. In terms of our results, a consensus statements and recommendations for the diagnosis and management of TBU were developed. This consensus statement provides an algorithmic approach toward diagnosing and managing TBU. These statements are meant to enhance but not replace individual clinician-patient interactions and to facilitate real-world clinical practice improvement in terms of TBU patients care.

Demographic Control Measure Implications of Tuberculosis Infection for Migrant Workers across Taiwan Regions

A sharp increase in migrant workers has raised concerns for TB epidemics, yet optimal TB control strategies remain unclear in Taiwan regions. This study assessed intervention efforts on reducing tuberculosis (TB) infection among migrant workers. We performed large-scale data analyses and used them to develop a control-based migrant worker-associated susceptible-latently infected-infectious-recovered (SLTR) model. We used the SLTR model to assess potential intervention strategies such as social distancing, early screening, and directly observed treatment, short-course (DOTS) for TB transmission among migrant workers and locals in three major hotspot cities from 2018 to 2023. We showed that social distancing was the best single strategy, while the best dual measure was social distancing coupled with early screening. However, the effectiveness of the triple strategy was marginally (1-3%) better than that of the dual measure. Our study provides a mechanistic framework to facilitate understanding of TB transmission dynamics between locals and migrant workers and to recommend better prevention strategies in anticipation of achieving WHO's milestones by the next decade. Our work has implications for migrant worker-associated TB infection prevention on a global scale and provides a knowledge base for exploring how outcomes can be best implemented by alternative control measure approaches.

Primary care providers' and nurses' knowledge, attitudes, and skills regarding latent TB infection testing and treatment: A qualitative study from Rhode Island

Background

Untreated latent tuberculosis infection (LTBI) is a major source of active tuberculosis disease in the United States. In 2016, the United States Preventive Services Task Force (USPSTF) recommended that screening for latent tuberculosis infection among individuals at increased risk be performed as routine preventive care. Traditionally, LTBI management–including both testing and treatment–has been conducted by specialists in the United States. It is believed that knowledge gaps among primary care team members and discomfort with LTBI treatment are significant barriers to LTBI management being conducted in primary care.

Methods and objectives

This qualitative study sought to evaluate the knowledge, attitudes, and skills of primary care team members regarding the LTBI care cascade, and to identify each stepwise barrier limiting primary care teams in following the USPSTF recommendations.

Results

We conducted 24 key informant interviews with primary care providers and nurses in Rhode Island. Our results demonstrate that overall, few primary care providers and nurses felt comfortable with LTBI management, and their confidence and comfort decreased throughout the cascade. Participants felt least confident with LTBI treatment and held misconceptions about LTBI testing, such as high cost. Although participants were not confident about LTBI treatment, most were enthusiastic about treating patients if provided additional training. Participants suggested that their lack of knowledge regarding LTBI treatment led to high rates of referral to specialist providers.

Conclusion

The gaps revealed in this study can inform training curricula for primary care team members in Rhode Island and nationally to shift the USPSTF policy into practice, and, ultimately, contribute to TB elimination in the United States.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on screening and treatment of tuberculosis infection in patients with inflammatory bowel disease

There is evidence that following the recommendations on screening and treatment of tuberculosis infection does not completely prevent the onset of tuberculosis in patients with inflammatory bowel disease. This fact, and the increasing use of new biologics and immunomodulators, has led the Spanish Group Working on Crohn's Disease and Ulcerative Colitis to update their recommendations for the prevention of tuberculosis in patients with inflammatory bowel disease. Diagnostic methods for latent tuberculosis infection, different scenarios in which screening is to be performed, strategies to reduce the risk of tuberculosis once biological treatment is initiated and chemoprophylaxis guidelines for latent tuberculosis infection are reviewed, as well as the management of active tuberculosis during biological treatment. Finally, there is a summary of the current recommendations within the paper and in an algorithm.

Effect of diabetes mellitus on risk of latent TB infection in a high TB incidence area: a community-based study in Taiwan

OBJECTIVE

To investigate the association between diabetes and latent tuberculosis infections (LTBI) in high TB incidence areas.

DESIGN

Community-based comparison study.

SETTING

Outpatient diabetes clinics at 4 hospitals and 13 health centres in urban and rural townships. A community-based screening programme was used to recruit non-diabetic participants.

PARTICIPANTS

A total of 2948 patients with diabetes aged older than 40 years were recruited, and 453 non-diabetic participants from the community were enrolled.

PRIMARY AND SECONDARY OUTCOME MEASURES

The interferon-gamma release assay (IGRA) and the tuberculin skin test were used to detect LTBI. The IGRA result was used as a surrogate of LTBI in logistic regression analysis.

RESULTS

Diabetes was significantly associated with LTBI (adjusted OR (aOR)=1.59; 95% CI 1.11 to 2.28) and age correlated positively with LTBI. Many subjects with diabetes also had additional risk factors (current smokers (aOR=1.28; 95% CI 0.95 to 1.71), comorbid chronic kidney disease (aOR=1.26; 95% CI 1.03 to 1.55) and history of TB (aOR=2.08; 95% CI 1.19 to 3.63)). The presence of BCG scar was protective (aOR=0.66; 95% CI 0.51 to 0.85). Duration of diabetes and poor glycaemic control were unrelated to the risk of LTBI.

CONCLUSION

There was a moderately increased risk of LTBI in patients with diabetes from this high TB incidence area. This finding suggests LTBI screening for the diabetics be combined with other risk factors and comorbidities of TB to better identify high-risk groups and improve the efficacy of targeted screening for LTBI.

The effect of combining QuantiFERON-TB Gold In-Tube test with tuberculin skin test on the detection of active tuberculosis

Background

Interferon-γ release assays (IGRAs) and tuberculin skin tests (TSTs) play an important role in the detection of tuberculosis (TB) infection. However, the interaction between these tests in detecting active pulmonary TB in adults has never been researched.

Methods

A matched case-control study was conducted in Taiwan from 1 March 2012 to 31 December 2013 by enrolling 150 confirmed TB cases and 852 matched controls dwelling at the same area (stratified by low, medium and high incidence).

Results

Compared with a negative QuantiFERON-TB Gold In-Tube (QFT-GIT) test and a negative tuberculin skin test (TST), the effect size for detecting active pulmonary TB was highest for both a positive QFT-GIT and positive TST (adjusted odds ratio [aOR] 8.77 [95% confidence interval {CI} 4.51 to 17.05]), but the detectability was substantially attenuated in the absence of either a positive TST (aOR 1.59 [95% CI 0.70 to 3.63]) or positive QFT-GIT (aOR 1.15 [95% CI 0.48 to 2.71]) after controlling for age and gender. The joint effect of detecting active TB was positively synergistic according to a large positive value of relative excess risk due to interaction (7.05 [95% CI 2.48 to 11.61]).

Conclusions

The administration of both the IGRA and TST for enhancing the detectability of active pulmonary TB in an area with a moderate prevalence of TB such as Taiwan is strongly suggested.

Serial Tuberculosis Screening in Inflammatory Bowel Disease Patients Receiving Anti-TNFα Therapy

BACKGROUND AND AIMS

One of the adverse effects of the tumour necrosis factor alpha [[TNFα] monoclonal antibodies for the treatment of immune-mediated inflammatory diseases is a higher propensity for tuberculosis development. The aim of this study was to explore the utility and sensitivity of serial tuberculosis screening during anti-TNFα treatment.

METHODS

A cohort of 46 inflammatory bowel disease patients receiving infliximab was prospectively recruited and followed for 26 months. During this period of time, a tuberculosis skin test and two different interferon ϒ release assays [QFT-GIT and T-SPOT.TB] were applied at 4-6-month intervals.

RESULTS

Overall, 16 patients were diagnosed with latent tuberculosis infection after having at least one test conversion: 12 patients had a positive tuberculosis skin test, seven patients had a positive T-SPOT.TB, and two patients had a positive QFT-GIT. Active tuberculosis was excluded in all; 15 were treated with isoniazid. A comparison between tests showed a moderate accuracy [72% to 85%] but low kappa values [0.063 to 0.377]. Concerning association with demographic and clinical characteristics, test conversion was more common among the male gender and those with a longer disease duration.

CONCLUSIONS

Tuberculosis tests conversions were common in inflammatory bowel disease patients treated with infliximab alone or in association with immunomodulators. In these immunosuppressed individuals, the classical tuberculosis skin test seems to have a higher sensitivity than the modern tests based on the release of interferonϒ.

A pulmonary tuberculosis outbreak in a long-term care facility

In long-term care facilities (LTCFs), the elderly are apt to be infected because those with latent tuberculosis infections (LTBIs) are at an increased risk for reactivation and post-primary TB disease. We report an outbreak of TB in staff and residents in a LTCF. An outbreak investigation was conducted after two TB cases were reported from the LTCF. A tuberculin skin test (TST), bacteriological examination and chest radiograph were administered to all facility staff and residents. An outbreak is defined as at least two epidemiologically linked cases that have identical Mycobacterium tuberculosis genotype isolates. This outbreak infected eight residents and one staff member, who were confirmed to have TB in a LTCF between September 2011 and October 2012. Based on the Becker method, the latent and infectious periods were estimated at 223·6 and 55·9 days. Two initial TST-negative resident contacts were diagnosed as TB cases through comprehensive TB screening. Observing elderly people who have a negative TST after TB screening appears to be necessary, given the long latent period for controlling a TB outbreak in a LTCF. It is important to consider providing LTBI treatment for elderly contacts.

Tuberculin skin test distribution following a change in BCG vaccination policy

Background

Epidemiologic data regarding tuberculin skin test (TST) responses are an important basis for TB control strategies. This study analyzed TST responses in Korea, which experienced a rapid change in BCG vaccination status.

Methods

TST responses in young adults were examined over 5 years. Participants with active TB lesions were excluded.

Results

A total of 5,552 participants were enrolled with median age of 21 years. When an induration diameter ≥10 mm was used as the criterion for a positive test, TST positivity fell (from 28.0% in 2005 to 15.3% in 2009); however, they remained steady when the criterion was ≥15–20 mm. A positive TST was associated with a personal or family of TB, the presence of a Bacille Calmette-Guérin (BCG) scar, and age (odds ratio [95% confidence interval] = 4.03 [2.61–6.22], 2.91 [1.80–4.71], 1.50 [1.31–1.72], and 1.15 [1.09–1.20], respectively). Among these factors, the decrease of participants with BCG scars was the most prominent change, which appeared to be associated with the change of TST positivity rate.

Conclusion

Overall, the rate of TST positivity in Korea decreased. However, this trend seems associated with the change of BCG vaccination strategy rather than successful control of LTBI. This study showed that change in BCG vaccination strategy can have great impact on TB epidemiologic survey based on TST.

Exposure to secondhand smoke and risk of tuberculosis: prospective cohort study

BACKGROUND

Prospective evidence on the association between secondhand-smoke exposure and tuberculosis is limited.

METHODS

We included 23,827 never smokers from two rounds (2001 and 2005) of Taiwan National Health Interview Survey. Information on exposure to secondhand smoke at home as well as other sociodemographic and behavioral factors was collected through in-person interview. The participants were prospectively followed for incidence of tuberculosis through cross-matching the survey database to the national tuberculosis registry of Taiwan.

RESULTS

A total of 85 cases of active tuberculosis were identified after a median follow-up of 7.0 years. The prevalence of exposure to secondhand smoke at home was 41.8% in the study population. In the multivariable Cox proportional hazards analysis, secondhand smoke was not associated with active tuberculosis (adjusted hazard ratio [HR], 1.03; 95% CI, 0.64 to 1.64). In the subgroup analysis, the association between secondhand smoke and tuberculosis decreased with increasing age; the adjusted HR for those <18, > = 18 and <40, > = 40 and <60, and > = 60 years old was 8.48 (0.77 to 93.56), 2.29 (0.75 to 7.01), 1.33 (0.58 to 3.01), and 0.66 (0.35 to 1.23) respectively. Results from extensive sensitivity analyses suggested that potential misclassification of secondhand-smoke exposure would not substantially affect the observed associations.

CONCLUSIONS

The results from this prospective cohort study did not support an overall association between secondhand smoke and tuberculosis. However, the finding that adolescents might be particularly susceptible to secondhand smoke's effect warrants further investigation.

Temporal trend analysis of avoidable mortality in Taiwan, 1971-2008: overall progress, with areas for further medical or public health investment

BACKGROUND

Avoidable mortality (AM), or "unnecessary untimely death," is considered an indicator of health care quality. We investigated trends in the age-standardized mortality rates (ASMRs) and associated standard expected years of life lost (SEYLL) for deaths amenable to medical care or public health measures in Taiwan from 1971-2008, with an emphasis on identifying areas where additional medical or public health investment may help reduce the burden of AM.

METHODS

Taiwan's ASMRs per 100,000 for AM and other causes of death were calculated using data from the National Death Certificate Registry in five-year bins from 1971 to 2008. SEYLL rates per 100,000 were calculated annually from 1971 to 2008 using the same data source.

RESULTS

ASMR for almost all AM and other causes of death declined dramatically from 1971 to 2008 except for lung cancer (16.6% and 7.4% increase among men and women, respectively) and breast cancer (109.8% increase among women). In the same period, SEYLL due to lung cancer increased from 269.2 to 555.7 for men and 249.7 to 342.5 for women. For women, SEYLL due to breast cancer increased from 263.5 in 1971 to 659.3 in 2008. There were gender-specific differences in the reduction (or increase) in AM rates, with women showing larger rates of reduction or smaller rates of increase. Among men, AM fell by 65.9% from 1971-1975 to 2006-2008, and deaths from other causes increased by 15.6%. Among women, AM and deaths from other causes fell by 80.8% and 59.8% respectively. SEYLL decreased, respectively among males and females, from 23,147.3 and 24,081.1 in 1971 to 11,261.8 and 5,929.6 in 2008.

CONCLUSION

From 1971 to 2008, Taiwan experienced a dramatic reduction in most AM and corresponding SEYLL except for lung cancer (for both males and females) and breast cancer (for females). Additional effort should be devoted to public health measures to combat the rising prevalence of smoking in Taiwan, which may be responsible for the increasing AM from lung cancer. If AM in breast cancer continues unabated in the future, greater policy emphasis on the early detection and treatment of breast cancer may also be warranted.

Seasonal dynamics of tuberculosis epidemics and implications for multidrug-resistant infection risk assessment

Understanding how seasonality shapes the dynamics of tuberculosis (TB) is essential in determining risks of transmission and drug resistance in (sub)tropical regions. We developed a relative fitness-based multidrug-resistant (MDR) TB model incorporated with seasonality and a probabilistic assessment model to assess infection risk in Taiwan regions. The model accurately captures the seasonal transmission and population dynamics of TB incidence during 2006-2008 and MDR TB in high TB burden areas during 2006-2010 in Taiwan. There is ~3% probability of having exceeded 50% of the population infected attributed to MDR TB. Our model not only provides insight into the understanding of the interactions between seasonal dynamics of TB and environmental factors but is also capable of predicting the seasonal patterns of TB incidence associated with MDR TB infection risk. A better understanding of the mechanisms of TB seasonality will be critical in predicting the impact of public control programmes.

Tuberculin skin test in bacille Calmette-Guérin-vaccinated children: how should we interpret the results?

BACKGROUND

The tuberculin skin test (TST) is the most useful method for the diagnosis of tuberculosis (TB). There is no evidence about the effect of bacillus Calmette-Guerin (BCG) vaccine on the interpretation of TST results.

OBJECTIVE

The aim of this study was to evaluate TST results in a population of immigrants and adopted children, analyzing the effect of the vaccine on TST.

METHODS

Cross-sectional observational study including immigrants or adopted children evaluated in our unit between January 2003 and December 2008 was made. Children diagnosed with TB, live attenuated virus vaccinated 2 months earlier, HIV-infected, chronically ill, or under treatment with immunosuppressive agents were excluded. TST was considered the dependent variable. Independent variables were gender, age, geographical origin, BCG scar, nutritional status, immune status, and intestinal parasites infestation.

RESULTS

One thousand seventy-four children were included, 69.6 % are female; their origin includes China (34.7 %), Latin America (20.8 %), India/Nepal (19.4 %), Eastern Europe (15.7 %), and Africa (9.3 %). BCG scar was present in 79 % of children. Mantoux = 0 mm in 84.4 %, <10 mm in 4.1 %, and ≥10 mm in 11.4 %. Only two variables, age and BCG scar, influenced TST result. Risk of a TST false-positive due to BCG disappears 3 years after vaccine administration.

CONCLUSIONS

A history of BCG vaccination at birth does not interfere with TST results in children >3 years old. Under 3 years of age, BCG does interfere with and may cause a false-positive TST result. In these cases, the use of interferon-gamma release assays (IGRAs) is recommended. If IGRAs are not available or when results are indeterminate, ignoring the antecedent of the vaccine is recommended.

A probabilistic transmission and population dynamic model to assess tuberculosis infection risk

The purpose of this study was to examine tuberculosis (TB) population dynamics and to assess potential infection risk in Taiwan. A well-established mathematical model of TB transmission built on previous models was adopted to study the potential impact of TB transmission. A probabilistic risk model was also developed to estimate site-specific risks of developing disease soon after recent primary infection, exogenous reinfection, or through endogenous reactivation (latently infected TB) among Taiwan regions. Here, we showed that the proportion of endogenous reactivation (53-67%) was larger than that of exogenous reinfection (32-47%). Our simulations showed that as epidemic reaches a steady state, age distribution of cases would finally shift toward older age groups dominated by latently infected TB cases as a result of endogenous reactivation. A comparison of age-weighted TB incidence data with our model simulation output with 95% credible intervals revealed that the predictions were in an apparent agreement with observed data. The median value of overall basic reproduction number (R₀) in eastern Taiwan ranged from 1.65 to 1.72, whereas northern Taiwan had the lowest R₀ estimate of 1.50. We found that total TB incidences in eastern Taiwan had 25-27% probabilities of total proportion of infected population exceeding 90%, whereas there were 36-66% probabilities having exceeded 20% of total proportion of infected population attributed to latently infected TB. We suggested that our Taiwan-based analysis can be extended to the context of developing countries, where TB remains a substantial cause of elderly morbidity and mortality.

Assessing the transmission risk of multidrug-resistant Mycobacterium tuberculosis epidemics in regions of Taiwan

OBJECTIVE

The objective of this study was to link transmission dynamics with a probabilistic risk model to provide a mechanistically explicit assessment for estimating the multidrug-resistant tuberculosis (MDR TB) infection risk in regions of Taiwan.

METHODS

A relative fitness (RF)-based MDR TB model was used to describe transmission, validated with disease data for the period 2006-2010. A dose-response model quantifying by basic reproduction number (R(0)) and total proportion of infected population was constructed to estimate the site-specific MDR TB infection risk.

RESULTS

We found that the incidence rate of MDR TB was highest in Hwalien County (4.91 per 100,000 population) in eastern Taiwan, with drug-sensitive and multidrug-resistant R(0) estimates of 0.89 (95% CI 0.23-2.17) and 0.38 (95% CI 0.05-1.30), respectively. The predictions were in apparent agreement with observed data in the 95% credible intervals. Our simulation showed that the incidence of MDR TB will be falling by 2013-2016. Our results indicated that the selected regions of Taiwan had only ∼1% probability of exceeding 50% of the population with infection attributed to MDR TB.

CONCLUSIONS

Our study found that the ongoing control programs implemented in Taiwan may succeed in curing most patients with MDR TB and will reduce the TB incidence countrywide.

Diagnostic value of EBUS-TBNA for lung cancer with non-enlarged lymph nodes: a study in a tuberculosis-endemic country

BACKGROUND

In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET.

METHODS

We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET.

CONCLUSION

In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred.

Positive tuberculin skin tests in nursing home residents in Southern Taiwan

In Taiwan, the tuberculin skin test (TST) is not recommended as a screening test for Mycobacterium tuberculosis (TB) infections. The aim of this study is to determine the prevalence and predictors of positive tuberculin reactivity and its association with TB infections among nursing home residents in Taiwan. A cross-sectional study and review of medical records were conducted at four nursing homes in Tainan City. A one-stage TST was performed by study nurses using two tuberculin units of purified protein derivative (PPD) of the RT23 strain. An induration ≥10 mm at 72 h was considered to be a positive reaction. Chest radiographs, acid-fast stains and mycobacterial cultures of three sputum samples were performed for those with a positive TST result. Of 115 residents (66.5% participation, mean age 73.1 years) who underwent a TST, 26 (22.6%) had a positive reaction. One woman was microbiologically diagnosed to have pulmonary TB. On multivariate analysis, a Bacille Calmette-Guérin (BCG) scar and a history of myocardial infarction were significantly associated with a positive TST. In conclusions, this study shows a considerable rate of positive TST among nursing home residents in southern Taiwan. A BCG scar and a history of myocardial infarction were associated with a positive TST.

Diagnostic performance of an enzyme-linked immunospot assay for interferon-gamma in extrapulmonary tuberculosis varies between different sites of disease

OBJECTIVES

To evaluate diagnostic performance of an enzyme-linked immunospot assay for interferon-gamma (T SPOT-TB) in patients with suspected extrapulmonary tuberculosis (TB).

METHODS

From January 2007 to December 2008, patients with suspected extrapulmonary TB were prospectively enrolled from 2 tertiary care hospitals.

RESULTS

A total of 138 patients with suspected extrapulmonary TB were enrolled; 50 patients had positive culture for Mycobacterium tuberculosis and 39 patients had probable TB. The sites of infection were lymph node (n = 20), pleura (n = 19), bone/joint (n = 15), urinary tract (n = 7), peritoneum (n = 7), meninges (n = 6), disseminated (n = 5), intestine (n = 3), pericardium (n = 2), skin (n = 2), throat (n = 1), neck (n = 1), and genitalia (n = 1). The overall sensitivity and specificity were 79.8% (71/89) and 81.6% (40/49). The sensitivity ranged from 100% for tuberculous meningitis, tuberculous pericarditis, and intestinal TB, 95% for lymphadenitis, to 42.9% for tuberculous peritonitis. The sensitivity of the T SPOT-TB assay was 70.6% in immunocompromised patients and 85.5% in immunocompetent patients (p = 0.09).

CONCLUSIONS

The T SPOT-TB assay can be a useful tool for diagnosing extra-pulmonary TB in immunocompetent and immunocompromised patients, particularly for tuberculous meningitis, pericarditis, lymphadenitis, and intestinal TB.

Safety of Etanercept in Patients at High Risk for Mycobacterial Tuberculosis Infections

Objective.

The magnitude of the risk of reactivation of tuberculosis (TB) on use of etanercept, especially in patients with positive purified protein derivative (PPD) test, has not been assessed. We evaluated the risk of developing active TB among PPD-positive patients treated with etanercept.

Methods.

All patients with a positive PPD test, as defined by American Thoracic Society guidelines, who received etanercept at Cook County Hospital from 2001 to 2008 were retrospectively reviewed. The primary endpoint was the development of active TB either while receiving or after completing etanercept therapy.

Results.

Four hundred eighty-seven patients received etanercept, of whom 84 were PPD-positive and constituted the primary cohort. The cohort was composed largely of patients who were at high risk for development of active TB: born in endemic area (80%), ethnic/racial minorities (51 Hispanic, 16 African American, and 8 Asian), and low socioeconomic status (66, 78.57%). Overall etanercept exposure was a mean of 24.6 months (range 3 to 60 mo), with 196 patient-years of etanercept exposure in PPD-positive individuals. Indications for etanercept use included rheumatoid arthritis 58 (69%), ankylosing spondylitis 11 (13%), psoriatic arthritis 13 (15.5%), juvenile inflammatory arthritis 1 (1.2%), and vasculitis 1 (1.2%). Of the 80 subjects, 74 received treatment for latent TB infection (LTBI) prior to initiating etanercept. A comprehensive review of these patients’ medical records failed to reveal any active TB infection.

Conclusion.

This systematic analysis suggests that the risk of reactivation of LTBI during etanercept therapy is low in appropriately treated individuals.

Tuberculous chemoprophylaxis requirements and safety in inflammatory bowel disease patients prior to anti-TNF therapy

BACKGROUND

Preventive actions are advised since the use of anti-tumor necrosis factor (TNF) agents is known to increase the risk of tuberculosis (TB). No data related to the effectiveness and safety of the preventive chemoprophylaxis (ChP) for TB in inflammatory bowel disease (IBD) patients are available. The goal was to evaluate the requirements, effectiveness, and safety profile of ChP in IBD patient candidates for anti-TNF therapy.

METHODS

All IBD patients diagnosed with latent TB while evaluated for anti-TNF therapy from the IBD database of 9 Spanish centers were included. Epidemiological and clinical data, risk factors for hepatotoxicity, ChP regimens, and side effects were registered.

RESULTS

Sixty-three out of 497 IBD evaluated patients (12.5%) had latent TB. Sixty-eight percent were on immunomodulators and 42% on systemic corticosteroids when a TB skin test (TST) was performed. The detection of a positive TST was done in 86% after a single exposure, but 14% needed a booster. All but 1 were treated with isoniazid alone for 6 or 9 months, and only 1 case required ChP discontinuation because of hepatotoxicity. No risk factors for hepatotoxicity were found. No cases of active TB were noticed in the 67 patients further treated with anti-TNF therapy.

CONCLUSIONS

More than 10% of Spanish IBD patients who are candidates for anti-TNF therapy have latent TB. TST retest is required to identify at least 14% of such patients; therefore, it should be considered if the initial TST is negative. ChP is safe in IBD patients even in those taking concomitant, potentially hepatotoxic drugs.

Comparison of the interferon- gamma release assay and the tuberculin skin test for contact investigation of tuberculosis in BCG-vaccinated health care workers

Health care workers are at increased risk of Mycobacterium tuberculosis infection. The tuberculin skin test (TST) is frequently false positive in BCG-vaccinated health care workers. QuantiFERON-TB GOLD (QFT-G) is a sensitive and specific interferon-gamma release assay unaffected by BCG vaccination. This study compared TST and QFT-G in the diagnosis of latent TB infection in BCG-vaccinated health care workers. 39 health care workers exposed to a smear-positive TB patient were enrolled. Initial TST was positive in 33 (84.6%) cases, but only 4 (10.2%) cases using QFT-G. TST conversion occurred in 2/6 (33.3%), compared to 4/32(12.5%), cases using QFT-G. A higher proportion of QFT converters was associated with intimate contact, although not reaching statistical significance. Face-to-face contact >1 h was significantly associated with QFT-G conversion >or=0.7 IU/ml (OR 8.63, 95%CI 1.08-69.07, p=0.04). Agreement between TST and QFT-G was 18.0%, (kappa: -0.03). Concordance between TST and QFT (>or=0.35 IU/ml) conversion was 40.0%(kappa=-0.40), and 60.0%(kappa=0.00) if QFT >or=0.7 IU/ml was used. Agreement increased with increasing TST cut-offs. TST is not useful in contact investigation among BCG-vaccinated health care workers, in an area with intermediate burden of TB. QFT may provide additional information for the diagnosis and strategic management of preventive treatment of LTBI in BCG-vaccinated health care workers in a country with intermediate burden of TB.

U.S. medical resident familiarity with national tuberculosis guidelines

Background

The ability of medical residents training at U.S. urban medical centers to diagnose and manage tuberculosis cases has important public health implications. We assessed medical resident knowledge about tuberculosis diagnosis and early management based on American Thoracic Society guidelines.

Methods

A 20-question tuberculosis knowledge survey was administered to 131 medical residents during a single routinely scheduled teaching conference at four different urban medical centers in Baltimore and Philadelphia. Survey questions were divided into 5 different subject categories. Data was collected pertaining to institution, year of residency training, and self-reported number of patients managed for tuberculosis within the previous year. The Kruskal-Wallis test was used to detect differences in median percent of questions answered correctly based on these variables.

Results

The median percent of survey questions answered correctly for all participating residents was 55%. Medical resident knowledge about tuberculosis did not improve with increasing post-graduate year of training or greater number of patients managed for tuberculosis within the previous year. Common areas of knowledge deficiency included the diagnosis and management of latent tuberculosis infection (median percent correct, 40.7%), as well as the interpretation of negative acid-fast sputum smear samples.

Conclusion

Many medical residents lack adequate knowledge of recommended guidelines for the management of tuberculosis. Since experience during training influences future practice pattterns, education of medical residents on guidelines for detection and early management of tuberculosis may be important for future improvements in national tuberculosis control strategies.

Risk of tuberculosis in patients treated with tumor necrosis factor antagonists due to incomplete prevention of reactivation of latent infection

OBJECTIVE

To evaluate the causes of new cases of active tuberculosis (ATB) in patients treated with tumor necrosis factor (TNF) antagonists included in the national registry BIOBADASER (Base de Datos de Productos Biológicos de la Sociedad Española de Reumatología) after the dissemination of recommendations to prevent reactivation of latent tuberculosis infection (LTBI).

METHODS

Incidence rate of ATB per 100,000 patient-years and 95% confidence intervals (95% CIs) were calculated in patients entering BIOBADASER after March 2002 and were stratified by compliance with recommendations (complete or incomplete). ATB rates in BIOBADASER were compared with the background rate and the rate in the rheumatoid arthritis cohort EMECAR (Estudio de la Morbilidad y Expresión Clínica de la Artritis Reumatoide) not treated with TNF antagonists. In addition, rates of ATB among patients treated with adalimumab, etanercept, and infliximab were estimated and compared only for treatments started after September 2003, when all 3 drugs became fully available.

RESULTS

Following March 2002, a total of 5,198 patients treated with a TNF antagonist were registered in BIOBADASER. Fifteen ATB cases were noted (rate 172 per 100,000 patient-years, 95% CI 103-285). Recommendations were fully followed in 2,655 treatments. The probability of developing ATB was 7 times higher when recommendations were not followed (incidence rate ratio 7.09, 95% CI 1.60-64.69). Two-step tuberculosis skin test for LTBI was the major failure in complying with recommendations.

CONCLUSION

New cases of ATB still occur in patients treated with all available TNF antagonists due to lack of compliance with recommendations to prevent reactivation of LTBI. Continuous evaluation of recommendations is required to improve clinical practice.