Tuberculosis presentation and outcomes in older Hispanic adults from Tamaulipas, Mexico.

Older people are at high risk of developing and dying from pulmonary infections like tuberculosis (TB), but there are few studies among them, particularly in Hispanics. To address these gaps, we sought to identify host factors associated with TB and adverse treatment outcomes in older Hispanics by conducting a cross-sectional study of TB surveillance data from Tamaulipas, Mexico (2006-2013; n = 8381). Multivariable logistic regressions were assessed for older adults (OA ≥65 years) when compared to young (YA, 18-39 years) and middle-aged adults (40-64 years). We found that the OA had features associated with a less complicated TB (e.g., lower prevalence of extra-pulmonary TB and less likely to abandon treatment or have drug resistant TB), and yet, were more likely to die during TB treatment (adj-OR 3.9, 95% 2.5, 5.25). Among the OA, excess alcohol use and low body mass index increased their odds of death during TB treatment, while a higher number of reported contacts (social support) was protective. Diabetes was not associated with adverse outcomes in OA. Although older age is a predictor of death during TB disease, OA are not prioritized by the World Health Organization for latent TB infection screening and treatment during contact investigations. With safer, short-course latent TB infection treatment available, we propose the inclusion of OA as a high-risk group in latent TB management guidelines.

Modeling the Impact of Recommendations for Primary Care-Based Screening for Latent Tuberculosis Infection in California.

OBJECTIVE: Targeted testing and treatment of persons with latent tuberculosis infection (LTBI) is a critical component of the US tuberculosis (TB) elimination strategy. In January 2016, the California Department of Public Health issued a tool and user guide for TB risk assessment (California tool) and guidance for LTBI testing, and in September 2016, the US Preventive Services Task Force (USPSTF) issued recommendations for LTBI testing in primary care settings. We estimated the epidemiologic effect of adherence to both recommendations in California. METHODS: We used an individual-based Markov micro-simulation model to estimate the number of cases of TB disease expected through 2026 with baseline LTBI strategies compared with implementation of the USPSTF or California tool guidance. We estimated the risk of LTBI by age and country of origin, the probability of being in a targeted population, and the probability of presenting for primary care based on available data. We assumed 100% adherence to testing guidance but imperfect adherence to treatment. RESULTS: Implementation of USPSTF and California tool guidance would result in nearly identical numbers of tests administered and cases of TB disease prevented. Perfect adherence to either recommendation would result in approximately 7000 cases of TB disease averted (40% reduction compared with baseline) by 2026. Almost all of this decline would be driven by a reduction in the number of cases among non-US-born persons. CONCLUSIONS: By focusing on the non-US-born population, adherence to LTBI testing strategies recommended by the USPSTF and the California tool could substantially reduce the burden of TB disease in California in the next decade.

Insights into culturally appropriate latent tuberculosis infection (LTBI) screening in NSW: perspectives of Indian and Pakistani migrants.

OBJECTIVE: Latent tuberculosis (LTBI) case-finding and treatment are a focus of TB elimination in Australia. We sought the perspectives of migrants from two high-burden countries likely to be targeted by this strategy. METHODS: To understand perceptions of migrant groups in Australia on LTBI screening, 28 in-depth interviews were conducted with Indian and Pakistani community members recruited purposively through local organisations in the Illawarra region, New South Wales. Drawing on local TB policy, data collected qualitatively was analysed using framework methodologies. RESULTS: Australia's immigration system prioritises migrants of higher socioeconomic status. Participants supported elimination but perceived TB as a disease of the poor and not relevant to them. Lack of understanding of LTBI and sensitivity to being 'targeted' are further barriers to screening participation. CONCLUSION: Information provision and targeting rationale are an essential preamble to LTBI screening. Migration appears to modify cultural attitudes to TB, but not significantly. Despite less stigma surrounding TB in Australian contexts, testing privacy and confidentiality, and limiting public identification of specific groups remain important to program acceptability. Implications for public health: Progress towards TB elimination can be enhanced by consulting with targeted communities, using existing networks for communication and service provision; emphasising prevention benefits.

The implementation of rifapentine and isoniazid (3HP) in two remote Arctic communities with a predominantly Inuit population, the Taima TB 3HP study.

Background: The incidence of TB among Inuit is the highest in Canada. A significantly shorter latent TB infection (LTBI) treatment with rifapentine and isoniazid once weekly for 12 weeks (3HP) is now available in limited settings in Canada.Methods: A prospective open-label 2-year observational postmarketing study was conducted introducing 3HP for the first time in Canada in Iqaluit followed by a program rollout in Qikiqtarjuaq, Nunavut.Results: A total of 247 people were offered 3HP, 102 in the Iqaluit postmarketing study and 145 in the Qikiqtarjuaq program roll out. Although statistical significance was not reached, more people who started treatment completed treatment in the 3HP group (Iqaluit, 60/73 (82.2%) and Qikiqtarjuaq, 89/115 (77.4%)) than in the historical control 9INHgroup (306/420 = 72.9%) (p = 0.2). Most of the adverse events in 3HP treated patients were associated with mild discomfort but no disruption of normal daily activity. Not drinking alcohol was associated with increased 3HP completion (OR 13.33, 95% CI, 2.27-78.20) as was not taking concomitant medications (OR 7.19, 95% CI, 1.47-35.30).Conclusions: The present study supports the feasibility and safety profile of 3HP for the treatment of LTBI in Nunavut.

Effectiveness of BCG Vaccination Against Mycobacterium tuberculosis Infection in Adults: A Cross-sectional Analysis of a UK-Based Cohort.

BACKGROUND: BCG appears to reduce acquisition of Mycobacterium tuberculosis infection in children, measured using interferon-gamma release assays (IGRAs). We explored whether BCG vaccination continues to be associated with decreased prevalence of M. tuberculosis infection in adults. METHODS: We conducted a cross-sectional analysis of data from adult contacts of tuberculosis cases participating in a UK cohort study. Vaccine effectiveness (VE) of BCG, ascertained based on presence of a scar or vaccination history, against latent tuberculosis infection (LTBI), measured via IGRA, was assessed using multivariable logistic regression. The effects of age at BCG and time since vaccination were also explored. RESULTS: Of 3453 recent tuberculosis contacts, 27.5% had LTBI. There was strong evidence of an association between BCG and LTBI (adjusted odds ratio = 0.70; 95% confidence interval, .56-.87; P = .0017) yielding a VE of 30%. VE declined with time since vaccination but there was evidence that LTBI prevalence was lower amongst vaccinated individuals even >20 years after vaccination, compared with nonvaccinated participants. CONCLUSIONS: BCG is associated with lower prevalence of LTBI in adult contacts of tuberculosis. These results contribute to growing evidence that suggests BCG may protect against M. tuberculosis infection as well as disease. This has implications for immunization programs, vaccine development, and tuberculosis control efforts worldwide. CLINICAL TRIALS REGISTRATION: NCT01162265.

Protocol for a cluster randomised control trial evaluating the efficacy and safety of treatment for latent tuberculosis infection in recent migrants within primary care: the CATAPuLT trial.

BACKGROUND: The identification and treatment of LTBI is a key component of the WHO's strategy to eliminate TB. Recent migrants from high TB-incidence countries are recognised to be at risk TB reactivation, and many high-income countries have focused on LTBI screening and treatment programmes for this group. However, migrants are the group least likely to complete the LTBI cascade-of-care. This pragmatic cluster-randomised, parallel group, superiority trial investigates whether a model of care based entirely within a community setting (primary care) will improve treatment completion compared with treatment in specialist TB services (secondary care). METHODS: The CATAPuLT trial (Completion and Acceptability of Treatment Across Primary Care and the community for Latent Tuberculosis) randomised 34 general practices in London, England, to evaluate the efficacy and safety of treatment for LBTI in recent migrants within primary care. GP practices were randomised to either provide management for LTBI entirely within primary care (GPs and community pharmacists) or to refer patients to secondary care. The target recruitment number for individuals is 576. The primary outcome is treatment completion (defined as taking at least 90% of antibiotic doses). The secondary outcomes assess adherence, acceptance of treatment, the incidence of adverse effects including drug-induced liver injury, the rates of active TB, patient satisfaction and cost-effectiveness of LTBI treatment. This protocol adheres to the SPIRIT Checklist. DISCUSSION: The CATAPuLT trial seeks to provide implementation research evidence for a patient-centred intervention to improve treatment completion for LTBI amongst recent migrants to the UK. TRIAL REGISTRATION: NCT03069807, March 2017, registered retrospectively.

Evaluation and treatment of latent tuberculosis infection among healthcare workers in Korea: A multicentre cohort analysis.

OBJECTIVE: Healthcare workers (HCWs) are one of the target groups for systematic testing and treatment of latent tuberculosis infection (LTBI) in a setting of low TB incidence. We performed this study to describe the testing of HCWs for LTBI and analyse the acceptance and completion of treatment of LTBI. METHODS: This retrospective cohort study was conducted in four university-affiliated hospitals between January 1 and December 31, 2018. HCWs with positive interferon-gamma release assay (IGRA) during LTBI screening were analysed. We assessed the acceptance and completion of LTBI treatment. RESULTS: Overall, 893 HCWs were IGRA positive. Among them, 609 HCWs visited the clinic for evaluation of LTBI. Of 609 HCWs who were evaluated, 302 (49.6%) were offered treatment for LTBI. The proportion of acceptance for treatment was 64.5% (195 of 302 HCWs). The treatment course was completed by 143 of 195 HCWs (73.3%). Three months of isoniazid and rifampin (3HR) was used in 137 HCWs (70.3%) and 4 months of rifampin (4R) in 58 (29.7%). 72 HCWs (36.9%) experienced at least one adverse drug events, but there was no different characteristics between completer and non-completer. CONCLUSION: The acceptance and completion of LTBI treatment were unsatisfactory. Subjective perspective regarding obstacles to treatment of LTBI needs to be explored to increase compliance to LTBI treatment.

A Feasibility Study for Diagnosis of Latent Tuberculosis Infection Using an IGRA Point-of-Care Platform in South Korea.

PURPOSE: This study aimed to evaluate ichroma™ IGRA-TB, a novel point-of-care platform for assaying IFN-γ release, and to compare it with QuantiFERON-TB Gold In-Tube (QFT-GIT) for identifying Mycobacterium tuberculosis (M. tb) infection. MATERIALS AND METHODS: We recruited 60 healthy subjects, and blood samples were obtained in QFT-GIT blood collection tubes. The blood collection tubes were incubated at 37°C, and culture supernatant was harvested after 18-24 hours. IFN-γ responses were assessed by the ichroma™ IGRA-TB cartridge and the QFT-GIT IFN-γ enzyme-linked immunosorbent assay. Three active TB patients were recruited as a positive control for M. tb infection. RESULTS: The area under the receiver operating characteristic curve of the ichroma™ IGRA-TB test for differentiating between infected and non-infected individuals was 0.9706 (p<0.001). Inconsistent positivity between the two tests was found in three participants who showed weak positive IFN-γ responses (<1.0 IU/mL) with QFT-GIT. However, the two tests had excellent agreement (95.2%, κ=0.91, p<0.001), and a very strong positive correlation was observed between the IFN-γ values of both tests (r=0.91, p<0.001). CONCLUSION: The diagnostic accuracy demonstrated in this study indicates that the ichroma™ IGRA-TB test could be used as a rapid diagnostic method for detecting latent TB infection. It may be particularly beneficial in resource-limited places that require cost-effective laboratory diagnostics.

High Prevalence of Active and Latent Tuberculosis in Children and Adolescents in Tibetan Schools in India: The Zero TB Kids Initiative in Tibetan Refugee Children.

BACKGROUND: Tuberculosis (TB) prevalence is high among Tibetan refugees in India, with almost half of cases occurring in congregate facilities, including schools. A comprehensive program of TB case finding and treatment of TB infection (TBI) was undertaken in schools for Tibetan refugee children. METHODS: Schoolchildren and staff in Tibetan schools in Himachal Pradesh, India, were screened for TB with an algorithm using symptoms, chest radiography, molecular diagnostics, and tuberculin skin testing. Individuals with active TB were treated and those with TBI were offered isoniazid-rifampicin preventive therapy for 3 months. RESULTS: From April 2017 to March 2018, we screened 5391 schoolchildren (median age, 13 years) and 786 staff in 11 Tibetan schools. Forty-six TB cases, including 1 with multidrug resistance, were found in schoolchildren, for a prevalence of 853 per 100 000. Extensively drug-resistant TB was diagnosed in 1 staff member. The majority of cases (66%) were subclinical. TBI was detected in 930 of 5234 (18%) schoolchildren and 334 of 634 (53%) staff who completed testing. Children in boarding schools had a higher prevalence of TBI than children in day schools (915/5020 [18%] vs 15/371 [4%]; P < .01). Preventive therapy was provided to 799 of 888 (90%) schoolchildren and 101 of 332 (30%) staff with TBI; 857 (95%) people successfully completed therapy. CONCLUSIONS: TB prevalence is extremely high among Tibetan schoolchildren. Effective active case finding and a high uptake and completion of preventive therapy for children were achieved. With leadership and community mobilization, TB control is implementable on a population level.

Latent Tuberculosis Infection Beliefs and Testing and Treatment Health Behaviors Amongst Non-US-Born South Asians in New Jersey: A Cross-Sectional Community Survey.

Latent tuberculosis infection (LTBI) remains a problem in the United States as reactivation leads to active TB disease particularly in persons with risk factors. The objective of this study is to assess the knowledge, attitudes and health behaviors related to testing and treatment of LTBI among non-US-born South Asians (SA) in New Jersey (NJ). A cross-sectional, community-based survey was the primary tool for gathering data. Eligibility criteria included being at least 18 years of age, self-identifying as SA, verbal consent for participation, and birth in a high TB endemic country. A hardcopy survey was distributed at local South Asian health fairs. The survey included questions about demographics, knowledge, beliefs on TB, and health behaviors (testing and treatment). Descriptive statistics were performed for all survey responses. Logistic regression models were constructed to assess the association of characteristics/beliefs and study outcomes. The survey sample size included 387 respondents. A total of 197 (54%) of respondents reported ever been tested for TB. Those who were tested for TB were generally younger, had higher educational levels, higher household incomes, and were more likely to have health insurance than those not ever tested for TB. Significantly more respondents who self-reported ever been tested for TB believed that TB was very or extremely serious (71.1% vs. 56.2%, p = 0.004). Also, significantly more respondents who self-reported ever been tested for TB believed that it was important to get tested (91.2% vs. 63.3%, p < 0.001). The survey analysis concluded that high-risk SA residents in NJ demonstrated a low rate of testing for TB.

Screening for latent tuberculosis infection by an Aboriginal Community Controlled Health Service, New South Wales, Australia, 2015.

OBJECTIVE: Ongoing transmission of tuberculosis (TB) continues in Indigenous communities in New South Wales (NSW), Australia. In a pilot project, a Public Health Unit TB team partnered with an Aboriginal Community Controlled Health Service (ACCHS) in a community with a cluster of TB to augment screening for latent TB infection (LTBI) using interferon-gamma release assay (IGRA). This study examined screening data and programme outcomes at 12 months post hoc to advise practice and policy formulation. METHODS: We conducted a retrospective, cross-sectional analysis of demographic and clinical data of ACCHS patients, stratified by IGRA testing status. Differences in sex and age distribution between the groups and cases of a genetically and epidemiologically linked TB cluster in Aboriginal people in NSW were assessed using non-parametric tests. RESULTS: Of 2019 Aboriginal and Torres Strait Islander people seen by general practitioners during the study period, 135 (6.7%) participated in the screening. Twenty-four (17.8%) participants were IGRA positive. One person was diagnosed with active TB. Twelve participants received a chest X-ray at the time of the positive test, and six participants had an additional chest X-ray within 12 months. None commenced preventive treatment for LTBI. DISCUSSION: ACCHS screening for LTBI reached individuals in the age group most commonly affected by TB in these Aboriginal communities. No conclusions can be made regarding the population prevalence due to the low screening rate. Further strategies need to be developed to increase appropriate follow-up and preventive treatment.

Estrategia secuencial para el cribado de la ITBL en inmigrantes recién llegados en situación social vulnerable / Sequential strategy for the LTBI screening of newly-arrived immigrants in vulnerable social situations

INTRODUCCIÓN: Algunos estudios indican altas prevalencias de infección tuberculosa latente (ITBL) en población inmigrante, lo que es relevante, pues el 5-10% de los casos desarrollaran una tuberculosis activa. El objetivo de este estudio es describir los resultados de una estrategia secuencial en población inmigrante recién llegada para el diagnóstico de ITBL usando la prueba de tuberculina (PT) e IGRAs. MÉTODOS: Se realizó un estudio descriptivo retrospectivo con inmigrantes entre 6 y 35años de edad de centros de acogida, derivados a una unidad de salud internacional entre julio de 2013 y junio de 2016. Se realizó la PT, y cuando fue ≥ 5 mm, se determinaron los IGRAs. La ITBL se definió como aquellos con IGRAs ≥ 0,35 UI/ml y radiografía de tórax normal. RESULTADOS: De los 184 casos, 138 (75,0%) eran hombres, de 23,0años de edad. Las áreas geográficas de origen más frecuente fueron: 63 (34,2%) de Asia, 42 (22,8%) de Europa del Este y 41 (22,3%) del África subsahariana. La PT fue ≥10mm en 79 (42,9%). La prevalencia de ITBL usando la estrategia secuencial fue de 33/184 (17,9%). El índice kappa de Cohen (entre PT ≥ 10mm e IGRAs) fue de 0,226. CONCLUSIÓN: Basar el diagnóstico de la ITBL tan solo en la PT puede representar una sobreestimación. Algunos estudios demuestran que el cribado secuencial sería el más coste-efectivo, y ello parece más evidente en las poblaciones vacunadas con BCG

INTRODUCTION: Some studies indicate high prevalences of latent tuberculosis infection (LTBI) in the immigrant population, which is relevant because 5-10% of cases will develop active tuberculosis. The objective of this study is to describe the results of a sequential strategy in the newly-arrived immigrant population for the diagnosis of LTBI using the tuberculin skin test (TST) and IGRAs. METHODS: A retrospective descriptive study was carried out with immigrants between 6 and 35years of age from shelters, referred to an international health unit between July 2013 and June 2016. The TST was performed and when it was ≥ 5mm, IGRAs were conducted. LTBI was defined as an IGRA ≥ 0.35IU/ml and normal chest X-ray. RESULTS: Of the 184 cases, 138 (75.0%) were men, 23.0 years of age. The most common geographical areas were: 63 (34.2%) from Asia, 42 (22.8%) from Eastern Europe and 41 (22.3%) from sub-Saharan Africa. The TST was ≥ 10mm in 79 cases (42.9%). The prevalence of LTBI using the sequential strategy was 33/184 (17.9%). Cohen's Kappa index (between TST ≥ 10mm and IGRAs) was 0.226. CONCLUSION: Basing LTBI screening on the TST alone could give rise to an overestimation. Some studies show that sequential screening would be the most cost-effective; this seems most evident in BCG-vaccinated populations

Yield of testing and treatment for tuberculosis among foreign-born persons during contact investigations in the United States: A semi-systematic review.

BACKGROUND: Contact investigation is an important strategy for maintaining control of tuberculosis (TB) in the United States. However, testing and treatment outcomes specifically to foreign-born populations are poorly understood. We reviewed literature on testing and LTBI identified during contact investigations in foreign-born populations living in the US. METHODS: We conducted a comprehensive search of peer-reviewed and grey literature using Cochrane systematic review methods. We included studies with adult and adolescent populations that were at least 50% foreign-born. Pooled proportions and 95% confidence intervals (CIs) were calculated via inverse-variance weighted meta-analysis, and cumulative proportions were calculated as products of adjacent step proportions. RESULTS: We identified 22 studies published between 1997 and 2014 that included at least 50% foreign-born participants. From studies of predominantly (>90%) foreign-born populations, almost all identified contacts were recruited and had valid test results, and 54.8% (95% CI 45.1-62.5%) of contacts with valid test results tested positive. From studies of majority (50% to 90%) foreign-born populations, 78.4% (95% CI 78.0-78.9%) of identified contacts were recruited, 92.0% (95% CI 91.6-92.3%) of recruited contacts had valid test results, and 38.5% (95% CI 31.9%-44.2%) of persons with valid results tested positive. These proportions varied by test type in studies of predominantly foreign-born populations. For every 1000 contacts identified in predominantly foreign-born populations, we estimate that 535 (95% CI 438 to 625) will test positive, and 354 (95% CI 244 to 453) will complete LTBI treatment. For every 1000 contacts identified in majority foreign-born populations, these estimates are 276 (95% CI 230 to 318), and 134 (95% CI 44 to 264), respectively. CONCLUSIONS: Contact investigation is a high yield activity for identifying and treating foreign-born persons with LTBI, but must be complemented by other tuberculosis control activities in order to achieve continued progress toward TB elimination.

Risk factors associated with the development of active tuberculosis among patients with advanced chronic kidney disease.

OBJECTIVES: The risk of developing active TB is greater in those receiving haemodialysis. This study aimed to describe the incidence of active tuberculosis among patients referred for management of kidney disease and dialysis in a high incidence UK city, with the purpose of informing latent TB testing and treatment practice. METHODS: Information from the tuberculosis register was cross-referenced with the Department of Renal Medicine patient information system. All patients seen between 1st January 2005 and 1st October 2016 were included in the analyses with the exception of those with prior TB. RESULTS: 68 cases of active TB were identified, an incidence of 126/100,000 patient-years (95% CI 97-169). Incidence was lowest in those with CKD 1 or 2 and rose as high as 256/100,000 patient-years (95% CI 183-374) in those receiving renal replacement therapy. 48% of cases were pulmonary and 87% of TB patients gave their ethnicity as either black/black British or Asian/Asian British, significantly more than in the non-TB renal group. Cases occurred steadily over the time period in which patients were in the cohort. CONCLUSION: TB incidence was very high among those receiving renal replacement therapy or CKD 4 or 5. Most cases occurred in those of an Asian/Asian British or black/black British background. Testing and treating such patients for latent TB is justified and should include those who have been receiving renal replacement therapy for some years.

LTBI among migrants by Mediterranean Sea: assessing prevalence and its variations according with different thresholds and diagnostic tools. A 10-month on-field experience.

Background: In 2016, 362 753 migrants reached Europe by sea. Most of migrants come from high tuberculosis (TB) burden countries and travel in conditions that increase the risk for communicable diseases. The goal of WHO End TB Strategy is to end global epidemic by 2035. Management of latent TB infection (LTBI) in low TB incidence countries is thus essential. Nevertheless, a lack of uniformity in policies and procedures for LTBI screening in Europe is perceived. The aim of this study was to estimate the LTBI prevalence in migrants by Mediterranean Sea. Methods: A cross-sectional study was conducted, involving 1038 migrants. Since a gold standard method is not available, LTBI prevalence was assessed in four alternative scenarios with different thresholds and diagnostic tools: (i) TST ≥ 5 mm; (ii) TST ≥ 10 mm; (iii) TST ≥ 5 mm plus IGRA; and (iv) TST ≥ 10 mm plus IGRA. TST = tuberculin skin test; IGRA = interferon-gamma release assay. Results: The four scenarios returned the following prevalence: (i) TST ≥ 5 mm: 40%; (ii) TST ≥ 10 mm: 33%; (iii) TST ≥ 5 mm plus IGRA: 27%; and (iv) TST ≥ 10 mm plus IGRA: 25%. Moreover, a positive association was found between the proportion of IGRA positive patients and the size of TST induration site. No patient who reported TST ≥ 18 mm tested IGRA negative. Conclusions: Prevalence varied substantially in the investigated scenarios. Significant differences were noted according with the nationality of migrants, probably attributable to different Bacillus Calmette-Guérin vaccination coverage rates in the countries of origin or different exposition to non-tuberculous mycobacteria infection. Data about the nationality can suggest the need of a tailored approach according to migrants' area of origin.

Universal screening for latent and active tuberculosis (TB) in asylum seeking children, Bochum and Hamburg, Germany, September 2015 to November 2016.

BackgroundIn Germany, the incidence of tuberculosis (TB) in children has been on the rise since 2009. High numbers of foreign-born asylum seekers have contributed considerably to the disease burden. Therefore, effective screening strategies for latent TB infection (LTBI) and active TB in asylum seeking children are needed. Aim: Our aim was to investigate the prevalence of LTBI and active TB in asylum seeking children up to 15 years of age in two geographic regions in Germany. Methods: Screening for TB was performed in children in asylum seeker reception centres by tuberculin skin test (TST) or interferon gamma release assay (IGRA). Children with positive results were evaluated for active TB. Additionally, country of origin, sex, travel time, TB symptoms, TB contact and Bacille Calmette-Guérin (BCG) vaccination status were registered. Results: Of 968 screened children 66 (6.8%) had TB infection (58 LTBI, 8 active TB). LTBI prevalence was similar in children from high (Afghanistan) and low (Syria) incidence countries (8.7% vs 6.4%). There were no differences regarding sex, age or travel time between infected and non-infected children. Children under the age of 6 years were at higher risk of progression to active TB (19% vs 2% respectively, p=0,07). Most children (7/8) with active TB were asymptomatic at the time of diagnosis. None of the children had been knowingly exposed to TB. Conclusions: Asylum seeking children from high and low incidence countries are both at risk of developing LTBI or active TB. Universal TB screening for all asylum seeking children should be considered.

Spatial clusters of latent tuberculous infection, Connecticut, 2010-2014.

SETTING: In the United States, tuberculosis (TB) control is increasingly focusing on the identification of persons with latent tuberculous infection (LTBI). OBJECTIVE: To characterize the local epidemiology of LTBI in Connecticut, USA. METHODS: We used spatial analyses 1) to identify census tract-level clusters of reported LTBI and TB disease in Connecticut, 2) to compare persons and populations in clusters with those not in clusters, and 3) to compare persons with LTBI to those with TB disease. RESULTS: Significant census tract-level spatial clusters of LTBI and TB disease were identified. Compared with persons with LTBI in non-clustered census tracts, those in clustered census tracts were more likely to be foreign-born and less likely to be of white non-Hispanic ethnicity. Populations in census tract clusters of high LTBI prevalence had greater crowding, persons living in poverty, and persons lacking health care insurance than populations not in clustered census tracts. Persons with LTBI were less likely than those with TB disease to be of Asian ethnicity, and persons with LTBI were more likely than those with TB disease to reside in a clustered census tract. CONCLUSIONS: Characterizing fine-scale populations at risk for LTBI supports effective and culturally accessible screening and treatment programs.

Sequential strategy for the LTBI screening of newly-arrived immigrants in vulnerable social situations. / Estrategia secuencial para el cribado de la ITBL en inmigrantes recién llegados en situación social vulnerable.

INTRODUCTION: Some studies indicate high prevalences of latent tuberculosis infection (LTBI) in the immigrant population, which is relevant because 5-10% of cases will develop active tuberculosis. The objective of this study is to describe the results of a sequential strategy in the newly-arrived immigrant population for the diagnosis of LTBI using the tuberculin skin test (TST) and IGRAs. METHODS: A retrospective descriptive study was carried out with immigrants between 6 and 35years of age from shelters, referred to an international health unit between July 2013 and June 2016. The TST was performed and when it was ≥5mm, IGRAs were conducted. LTBI was defined as an IGRA ≥0.35IU/ml and normal chest X-ray. RESULTS: Of the 184 cases, 138 (75.0%) were men, 23.0 years of age. The most common geographical areas were: 63 (34.2%) from Asia, 42 (22.8%) from Eastern Europe and 41 (22.3%) from sub-Saharan Africa. The TST was ≥10mm in 79 cases (42.9%). The prevalence of LTBI using the sequential strategy was 33/184 (17.9%). Cohen's Kappa index (between TST≥10mm and IGRAs) was 0.226. CONCLUSION: Basing LTBI screening on the TST alone could give rise to an overestimation. Some studies show that sequential screening would be the most cost-effective; this seems most evident in BCG-vaccinated populations.

Latent Tuberculosis Infection Testing Practices in Long-Term Care Facilities, Boston, Massachusetts.

OBJECTIVES: To describe latent tuberculosis infection (LTBI) testing practices in long-term care facilities (LTCFs). DESIGN: Retrospective cohort study. SETTING: Three Boston-area LTCFs. PARTICIPANTS: Residents admitted between January 1 and December 31, 2011. MEASUREMENTS: Resident demographic characteristics, comorbidities, LTCF stay, and LTBI testing and treatment. RESULTS: Data for 291 LTCF residents admitted in 2011 were reviewed. Of the 257 without a history of LTBI and with documentation of testing, 162 (63%) were tested; 114 of 186 (61%) with a stay less than 90 days and 48 of 71 (68%) with a stay of 90 days or longer were tested. Of 196 residents with data on prior LTBI testing, 39 (19.9%) had LTBI; 12 of these (30.8%) were diagnosed at the LTCF. Hispanic participants were more likely than black participants to undergo LTBI testing (adjusted odds ratio (aOR) = 2.4, P = .003). Having a length of stay of less than 90 days (aOR = 0.7, P < .001) and history of illicit drug use (aOR = 0.7, P < .001) were associated with lower odds of LTBI testing. CONCLUSION: One-fifth of LTCF residents had LTBI, but testing was not always performed. The high prevalence of LTBI in older adults combined with the risk of an outbreak if a case of tuberculosis occurs in a LTCF make LTBI testing and treatment an important prevention opportunity. The importance of LTBI testing in LTCFs needs to be reinforced.

Resistance to First-Line Antituberculosis Drugs in Washington State by Region of Birth and Implications for Latent Tuberculosis Treatment Among Foreign-Born Individuals.

The United States has a low burden of drug resistance among tuberculosis (TB) cases compared with other world regions. TB is increasingly concentrated among foreign-born individuals who have higher rates of drug resistance than U.S.-born individuals. While universal drug susceptibility testing is the standard for detecting active tuberculosis, there are limited guidelines for latent tuberculosis infection (LTBI) treatment based on risk factors for drug resistance. To quantify the variable risk of drug resistance among foreign-born individuals, all TB cases in Washington State between 1994 and 2014 with drug resistance data for isoniazid, rifampin, pyrazinamide, and ethambutol were divided into eight regions of birth. Logistic regression was used to characterize regional differences in resistance patterns. Genotypic cluster and lineage data were compared against drug resistance in a subanalysis. Among 4,298 cases, isoniazid resistance was more common in foreign-born individuals (12.6% versus 4.8%; P < 0.001), with the highest burden among individuals from the Asia-Pacific (14.8%) region. Rifampin resistance was slightly higher among foreign-born individuals (1.9% versus 1.1%; P = 0.063). Multivariate logistic regression demonstrated that older age was associated with a lower risk of resistance to isoniazid and rifampin (odds ratio [OR] = 0.86, P = 0.006 and OR = 0.64, P = 0.003 for each 20-year interval, respectively). These data suggest drug resistance in LTBI will remain a challenge and that rifampin-based regimens for treatment of LTBI in non-human immunodeficiency virus-infected adults may be preferable for individuals born in regions with high levels of isoniazid resistance. However, further research is needed to demonstrate whether LTBI treatment based on region of birth further decreases TB reactivation.