Evaluation of immigrant tuberculosis screening in industrialized countries

Prevalence of HIV, Hepatitis C and Hepatitis B Infection Among Detainees in a French Administrative Detention Centre

BACKGROUND

In France, migrants constitute a significant proportion of people diagnosed with HIV, hepatitis C (HCV) and B (HBV). This study estimated the prevalence of these three viruses among detainees at a French administrative detention centre (CRA), through systematic Rapid Diagnostic Test (RDT) screening.

METHODS

This prospective, single-centre, cross-sectional, pilot study included detainees at the Nîmes CRA from February to December 2022. The primary endpoint was HIV, HCV and HBV prevalence determined by RDT. Secondary outcomes were: co-infections; study acceptability, reasons for non-inclusion, causes of non-contributory samples; and concordance between serological tests and RDT.

RESULTS

Among the 350 people agreeing to participate of 726 eligible, five refused the RDT, leaving 345 analysable participants for a participation rate of 47.5% (345/726). Participants were predominantly male (90%) with an average age of 31 years. The most common country of origin was Algeria (34%). Twenty (6%) had taken drugs intravenously and 240 (70%) had had unprotected sex within a median of 4.92 [1.08; 15] months. Virus prevalence was: 0% HIV; 4.64 [2.42; 6.86] % HCV; and 2.32 [1.01; 4.52] % HBV. Eleven (73%) of the RDT HCV positive cases were confirmed serologically. RDT detected one false-positive HCV case, as an anti-HCV Ac serological test was negative. Of the eight patients with positive HBV RDT, one declined the serology testing, thus 100% (7/7) of the tested RDT positive cases were confirmed by serology.

CONCLUSION

The study highlighted the need to screen detainees for HIV, HCV and HBV infection and suitability of RDTs.

A Quasi-experimental Study on the Effect of Pre-entry Tuberculosis Screening for Immigrants on Treatment Outcomes in South Korea: A Difference-in-Differences Analysis

OBJECTIVE

This study ascertains the effects of the pre-entry tuberculosis (TB) screening policy, which was implemented as a strategy for managing TB among immigrants, on the treatment outcomes of immigrants in South Korea.

METHODS

This study linked three different datasets from 2013 to 2018, namely (1) Korean National Tuberculosis Surveillance System; (2) National Health Information Database for patients diagnosed with TB with ICD code A15-A19, B90, or U84.3; and (3) Statistics Korea database related to cause of deaths. To identify the effect of the policy, cohorts comprising Korean and immigrant TB patients notified before (January 1, 2013-December 31, 2015) and after (September 1, 2016-December 31, 2018), the implementations of the policy were established. A difference-in-differences (DID) analysis of the treatment success and mortality rates was performed.

RESULTS

Data from 100,262 TB patients were included in the analysis (before policy implementation: 1240 immigrants and 65,723 Koreans; after policy implementation: 256 immigrants and 33,043 Koreans). The propensity score matching-DID analysis results showed that the difference in the treatment success rate between immigrants and Koreans decreased significantly, from 16% before to 6% after the policy implementation. The difference in the mortality rate between the two groups decreased from - 3% before to - 1% after the policy implementation; however, this difference was insignificant.

CONCLUSION

The treatment outcomes of immigrant TB patients in South Korea improved after the implementation of the pre-entry active TB screening policy. Future immigrant TB policies should consider establishing active patient support strategies and a healthcare collaboration system between countries.

A Systematic Review on Pulmonary TB Burden and Associated Factors Among Immigrants in the UK

Background

The rapid growth of international human migration has positioned the UK in the top five countries in the world with 9.4 million immigrants in 2022. These immigrants originate from low- and middle-income countries and remain particularly at risk of developing TB. In the UK, the number of TB cases has been increasing, and the influx of immigrants could be a contributing factor.

Objective

This review aims to map the burden of pulmonary TB among immigrants in the UK and investigate associated factors. It also reviews the TB management approaches among immigrants in the UK.

Design

The study utilized PRISMA guidelines to search electronic databases (PubMed and EMBASE) for articles published from 2000 to 2022 on TB prevalence and factors in immigrants and explored government websites for TB management strategies.

Results

Nineteen out of 530 initially identified articles were included. The included studies reported a prevalence rate of TB among immigrants ranging from 0.04 to 52.1%, showing a decrease in the burden over time. Additionally, a higher number of TB cases were observed among immigrants from the Asian region, particularly immigrants from South Asia, followed by those from sub-Saharan Africa. Stigma, misconception about the disease, language barrier, lack of confidentiality, and unfriendly healthcare system for immigrants were the main drivers of the TB burden among immigrants. The TB management approaches in the UK include pre-entry screening for active TB, LTBI testing for a specific population group, and antibacterial therapy for 3-6 months for TB patients.

Conclusion

The UK's control and prevention efforts in reducing tuberculosis prevalence among immigrants show optimism, but challenges persist. Key improvements include healthcare delivery, TB improvement programs, and policies addressing stigma and patient confidentiality.

Tuberculosis related barriers and facilitators among immigrants in Atlantic Canada: A qualitative study

Tuberculosis (TB) is a disease caused by the bacterium Mycobacterium tuberculosis and affects approximately one-quarter of the world's population. Immigrant populations in Canada are disproportionately affected by TB. Canada's immigration medical examinations include screening for active TB but not latent TB infection (LTBI). In LTBI, the bacterium remains dormant within the host but can reactivate and cause disease. Once active, TB can be transmitted to close contacts sharing confined spaces leading to the possibility of outbreaks in the broader community. This study aimed to 1) assess the current TB knowledge, perceived risk, and risk behaviors of immigrants in Atlantic Canada as well as 2) identify barriers and facilitators to testing and treatment of TB among this population. Three focus group discussions were conducted with a total of 14 non-Canadian born residents of New Brunswick aged 19 years and older. Data were analyzed using inductive thematic analysis. Four themes were identified from the data relating to barriers to testing and treatment of LTBI: 1) Need for education, 2) stigma, 3) fear of testing, treatment, and healthcare system, and 4) complacency. Results included reasons individuals would not receive TB testing, treatment, or seek help, as well as facilitators to testing and treatment. These findings may inform the implemention of an LTBI screening program in Atlantic Canada and more broadly across the country.

Importance of Tuberculosis Screening of Resident Visa Applicants in Low TB Incidence Settings: Experience from Oman

Introduction

For Oman, a country targeting tuberculosis (TB) elimination, TB among expatriates is a major challenge. Thus, screening for active TB using chest X-ray was made mandatory for expatriates’ residency renewals.

Objective

To estimate the incidence of bacteriologically confirmed TB and assess impact of chest X-ray based TB screening among expatriates in Muscat Governorate.

Methods

Applicants for residency and renewals were mandated for chest X-ray-based TB screening in 2018. We collected data of screened subjects with radiological suspicion of TB who were subjected to further bacteriological evaluation.

Results

Of 501,290 applicants screened during the study period, 436 (0.09%) had X-ray findings suggestive of TB. Among the 436, TB was confirmed in 53 (12.2%; 95% CI 9.2–15.6), giving an overall prevalence of 10.6 (95% CI 8–13.9) per 100,000 applicants (number needed to be screened 9458). Among renewals, the point prevalence of TB was 10.5 per 100,000 expatriates screened (95% CI 6.9–14.04 per 100,000), with a mean follow-up period of 11.8 years.

Conclusion

Our findings are consistent with the recommendation for utilization of chest X-ray as a preferred tool for active case finding in the setting of expatriate screening. Our findings are also suggestive of the need for latent TB screening and ruling out TB prior to latent TB treatment.

Effectiveness of nationwide programmatic testing and treatment for latent tuberculosis infection in migrants in England: a retrospective, population-based cohort study

Background

In low-incidence countries, tuberculosis mainly affects migrants, mostly resulting from reactivation of latent tuberculosis infection (LTBI) acquired in high-incidence countries before migration. A nationwide primary care-based LTBI testing and treatment programme for migrants from high-incidence countries was therefore established in high tuberculosis incidence areas in England. We aimed to assess the effectiveness of this programme.

Methods

We did a retrospective, population-based cohort study of migrants who registered in primary care between Jan 1, 2011, and Dec 31, 2018, in 55 high-burden areas with programmatic LTBI testing and treatment. Eligible individuals were aged 16–35 years, born in a high-incidence country, and had entered England in the past 5 years. Individuals who tested interferon-γ release assay (IGRA)-negative were advised about symptoms of tuberculosis, whereas those who tested IGRA-positive were clinically assessed to rule out active tuberculosis and offered preventive therapy. The primary outcome was incident tuberculosis notified to the national Enhanced Tuberculosis Surveillance system.

Findings

Our cohort comprised 368 097 eligible individuals who had registered in primary care, of whom 37 268 (10·1%) were tested by the programme. 1446 incident cases of tuberculosis were identified: 166 cases in individuals who had IGRA testing (incidence 204 cases [95% CI 176–238] per 100 000 person-years) and 1280 in individuals without IGRA testing (82 cases [77–86] per 100 000 person-years). Overall, in our primary analysis including all diagnosed tuberculosis cases, a time-varying association was identified between LTBI testing and treatment and lower risk of incident tuberculosis (hazard ratio [HR] 0·76 [95% CI 0·63–0·91]) when compared with no testing. In stratified analysis by follow-up period, the intervention was associated with higher risk of tuberculosis diagnosis during the first 6 months of follow-up (9·93 [7·63–12·9) and a lower risk after 6 months (0·57 [0·41–0·79]). IGRA-positive individuals had higher risk of tuberculosis diagnosis than IGRA-negative individuals (31·9 [20·4–49·8]). Of 37 268 migrants who were tested, 6640 (17·8%) were IGRA-positive, of whom 1740 (26·2%) started preventive treatment. LTBI treatment lowered the risk of tuberculosis: of 135 incident cases in the IGRA-positive cohort, seven cases were diagnosed in the treated group (1·87 cases [95% CI 0·89–3·93] per 1000 person-years) and 128 cases were diagnosed in the untreated group (10·9 cases [9·16–12·9] per 1000 person-years; HR 0·14 [95% CI 0·06–0·32]).

Interpretation

A low proportion of eligible migrants were tested by the programme and a small proportion of those testing positive started treatment. Despite this, programmatic LTBI testing and treatment of individuals migrating to a low-incidence region is effective at diagnosing active tuberculosis earlier and lowers the long-term risk of progression to tuberculosis. Increasing programme participation and treatment rates for those testing positive could substantially impact national tuberculosis incidence.

Funding

National Institute for Health Research Health Protection Research Unit in Respiratory Infections.

Overseas Treatment of Latent Tuberculosis Infection in US–Bound Immigrants

Seventy percent of tuberculosis (TB) cases in the United States occur among non–US-born persons; cases usually result from reactivation of latent TB infection (LTBI) likely acquired before the person’s US arrival. We conducted a prospective study among US immigrant visa applicants undergoing the required overseas medical examination in Vietnam. Consenting applicants >15 years of age were offered an interferon-γ release assay (IGRA); those 12–14 years of age received an IGRA as part of the required examination. Eligible participants were offered LTBI treatment with 12 doses of weekly isoniazid and rifapentine. Of 5,311 immigrant visa applicants recruited, 2,438 (46%) consented to participate; 2,276 had an IGRA processed, and 484 (21%) tested positive. Among 452 participants eligible for treatment, 304 (67%) initiated treatment, and 268 (88%) completed treatment. We demonstrated that using the overseas medical examination to provide voluntary LTBI testing and treatment should be considered to advance US TB elimination efforts.

Invited Commentary: The Role of Tuberculosis Screening Among Migrants to Low-Incidence Settings in (Not) Achieving Elimination

The cost-effectiveness of migrant tuberculosis prevention programs is highly relevant to many countries with low tuberculosis incidence as they attempt to eliminate the disease. Dale et al. (Am J Epidemiol. 2022;191(2):255-270) evaluated strategies for tuberculosis infection screening and treatment among new migrants to Australia. Screening for infection before migration, and then administering preventive treatment after arrival, was more cost-effective than performing both screening and treatment after arrival. From the Australian health payer perspective, the improved cost-effectiveness of premigration screening partly reflected the shift of screening costs to migrants, which may raise ethical concerns. Key sensitivity analyses highlighted the influence of health disutility associated with tuberculosis preventive treatment, and of posttreatment sequelae of tuberculosis disease. Both considerations warrant greater attention in future research. For all strategies, the impact on tuberculosis incidence among migrants was modest (<15%), suggesting enhanced migrant screening will not achieve tuberculosis elimination in low-incidence settings. This emphasizes the need to increase investment and effort in global tuberculosis prevention and care, which will ultimately reduce the prevalence of tuberculosis infection and therefore the risk of tuberculosis disease among migrants. Such efforts will benefit high and low tuberculosis incidence countries alike, and advance all countries further toward tuberculosis elimination.

Targeting screening and treatment for latent tuberculosis infection towards asylum seekers from high-incidence countries - a model-based cost-effectiveness analysis

Background

Enhancing tuberculosis (TB) prevention and care in a post-COVID-19-pandemic phase will be essential to ensure progress towards global TB elimination. In low-burden countries, asylum seekers constitute an important high-risk group. TB frequently arises post-immigration due to the reactivation of latent TB infection (LTBI). Upon-entry screening for LTBI and TB preventive treatment (TPT) are considered worthwhile if targeted to asylum seekers from high-incidence countries who usually present with higher rates of LTBI. However, there is insufficient knowledge about optimal incidence thresholds above which introduction could be cost-effective. We aimed to estimate, among asylum seekers in Germany, the health impact and costs of upon-entry LTBI screening/TPT introduced at different thresholds of country-of-origin TB incidence.

Methods

We sampled hypothetical cohorts of 30–45 thousand asylum seekers aged 15 to 34 years expected to arrive in Germany in 2022 from cohorts of first-time applicants observed in 2017–2019. We modelled LTBI prevalence as a function of country-of-origin TB incidence fitted to data from observational studies. We then used a probabilistic decision-analytic model to estimate health-system costs and quality-adjusted life years (QALYs) under interferon gamma release assay (IGRA)-based screening for LTBI and rifampicin-based TPT (daily, 4 months). Incremental cost-effectiveness ratios (ICERs) were calculated for scenarios of introducing LTBI screening/TPT at different incidence thresholds.

Results

We estimated that among 15- to 34-year-old asylum seekers arriving in Germany in 2022, 17.5% (95% uncertainty interval: 14.2–21.6%) will be latently infected. Introducing LTBI screening/TPT above 250 per 100,000 country-of-origin TB incidence would gain 7.3 (2.7–14.8) QALYs at a cost of €51,000 (€18,000–€114,100) per QALY. Lowering the threshold to ≥200 would cost an incremental €53,300 (€19,100–€122,500) per additional QALY gained relative to the ≥250 threshold scenario; ICERs for the ≥150 and ≥ 100 thresholds were €55,900 (€20,200–€128,200) and €62,000 (€23,200–€142,000), respectively, using the next higher threshold as a reference, and considerably higher at thresholds below 100.

Conclusions

LTBI screening and TPT among 15- to 34-year-old asylum seekers arriving in Germany could produce health benefits at reasonable additional cost (with respect to international benchmarks) if introduced at incidence thresholds ≥100. Empirical trials are needed to investigate the feasibility and effectiveness of this approach.

Tuberculosis in migrants to Australia: Outcomes of a national screening program

Background: Few low-incidence countries are on track to achieve the ambitious target of reaching TB pre-elimination by 2035. Australia is a high-income country with a low burden of TB, which is particularly concentrated in migrant populations. As part of Australia's migration program, permanent, provisional and humanitarian visa applicants are screened for TB, along with some applicants for temporary visas.

Methods: We calculated the prevalence of all forms of active TB and bacteriologically-confirmed TB among onshore and offshore applicants for visas to Australia from July 2014 to June 2017, and investigated associated risk factors using logistic regression.

Findings: Visa applicants were predominantly young adults from various Asian countries. Among 2,381,217 applicants, 1263 cases of active TB were diagnosed, including 852 cases of bacteriologically-confirmed TB. Overall TB prevalence was 53.0 per 100,000, corresponding to one TB diagnosis for every 1887 applicants screened. TB rates increased with age and were higher among humanitarian applicants and those previously treated for TB, although most cases occurred in applicants without these risk factors. TB prevalence by country of origin was similar to WHO estimates for some countries, but considerably lower for others. For several highly represented countries of origin, rates appear to have fallen relative to earlier comparable studies.

Interpretation: Prevalence of TB among visa applicants to Australia and the consequent risk to the Australian community appear to be declining and remain low. In this context, support for TB control programs overseas and preventive interventions are likely to have the greatest impact on domestic TB burden.

Funding: No specific funding was received for this study. JMT is a recipient of an Early Career Fellowship from the Australian National Health and Medical Research Council (APP1142638).

Trend and treatment outcomes of latent tuberculosis infection among migrant persons in Japan: retrospective analysis of Japan tuberculosis surveillance data

BACKGROUND

Screening for latent tuberculosis infection (LTBI) among migrant population has become a critical issue for many low tuberculosis (TB) burden countries. Evidence regarding effectiveness of LTBI programs are limited, however, partly because of paucity of national data on treatment outcomes for LTBI. In Japan, notification of LTBI is mandatory, and its treatment outcome is reported as part of Japan's national TB surveillance system. We thus conducted a detailed analysis of LTBI among foreign-born persons, to update the epidemiological trend of newly notified LTBI between 2007 and 2018, and to examine the treatment regimen and outcome of those notified in 2016 and 2017, focusing specifically on the potential risk factors for lost to follow-up.

METHODS

We extracted and analyzed the data of newly notified LTBI patients from the Japan Tuberculosis Surveillance System to examine the overall trend of notification and by age groups and modes of detection between 2007 and 2018, and the cohort data for treatment regimen and outcomes of foreign-born persons notified with LTBI in 2016 and 2017. Trends and proportions were summarized descriptively, and logistic regression analysis was conducted to identify potential risk factors for lost to follow-up. Comparisons were made with the Japan-born patients where appropriate, using chi-squared tests.

RESULTS

Both the number and proportion of LTBI among foreign-born persons have been constantly increasing, reaching 963 cases in 2018. Cohort analysis of the surveillance data indicated that the proportion of those on shorter regimen was higher among the foreign- than Japan-born patients (5.5% vs. 1.8%, p < 0.001). The proportion of those who have been lost to follow-up and transferred outside of Japan combined was higher among the foreign- than Japan-born patients (12.0% vs, 8.2%, p < 0.001). Risk factors for lost to follow-up were being employed on a temporal basis, and job status unknown (adjusted odds ratios 3.11 and 4.09, 95% confidence intervals 1.34-7.26 and 1.60-10.48, respectively).

CONCLUSIONS

Migrant population face greater risk of interrupting LTBI treatment, and interventions to improve adherence are a critical component of programmatic management of LTBI. Further studies are needed to explore the cultural and socioeconomic situation in which foreign-born persons undergo LTBI treatment in Japan.

Latent tuberculosis in migrants travelling through the northeast regions of Mexico

Background

Latent tuberculosis infection (LTBI) affects nearly a quarter of the global population. Public health interventions aimed at interrupting tuberculosis transmission do not routinely include systematic screening of migrant populations for LTBI in Mexico, nor other high-income countries. However, early detection and treatment of LTBI in immigrant populations from high-burden countries are recommended by the World Health Organization.

Objective

The objective of this study was to determine the proportion of migrants with LTBI in shelters in northeastern Mexico.

Methods

In this cross-sectional study, blood samples were obtained from 455 migrants living in shelters in northeastern Mexico during January 2017 to October 2019. LTBI was diagnosed using the QuantiFERON®-TB Gold Plus test.

Results

Most of the migrants evaluated in this study were from Honduras; ∼86% were male; the average age was 29 ± 10 years. LTBI was identified in 18.4% of those from Central America. Migrants from El Salvador and Nicaragua were more likely to have LTBI than those from Honduras or Guatemala. Overweight or obese persons and older persons had a higher prevalence of LTBI. We detected no significant differences with respect to LTBI when the results were compared based on gender, education, or marital status.

Conclusion

The LTBI rates amongst migrants from Central America recently screened in shelters in northeastern Mexico appears to be relatively low given recent estimates of LTBI prevalence in Mexico.

Tuberculosis in migrants - screening, surveillance and ethics

Tuberculosis (TB) is the leading infectious cause of human mortality and is responsible for nearly 2 million deaths every year. It is often regarded as a ‘silent killer’ because it predominantly affects the poor and marginalized, and disease outbreaks occur in ‘slow motion’ compared to Ebola or coronavirus 2 (COVID-19). In low incidence countries, TB is predominantly an imported disease and TB control in migrants is pivotal for countries to progress towards TB elimination in accordance with the World Health Organisations (WHO’s) End TB strategy. This review provides a brief overview of the different screening approaches and surveillance processes that are in place in low TB incidence countries. It also includes a detailed discussion of the ethical issues related to TB screening of migrants in these settings and the different interests that need to be balanced. Given recognition that a holistic approach that recognizes and respects basic human rights is required to end TB, the review considers the complexities that require consideration in low-incidence countries that are aiming for TB elimination.

Cost-effectiveness of Latent Tuberculosis Infection Screening before Immigration to Low-Incidence Countries

Prospective migrants to countries where the incidence of tuberculosis (TB) is low (low-incidence countries) receive TB screening; however, screening for latent TB infection (LTBI) before immigration is rare. We evaluated the cost-effectiveness of mandated and sponsored preimmigration LTBI screening for migrants to low-incidence countries. We used discrete event simulation to model preimmigration LTBI screening coupled with postarrival follow-up and treatment for those who test positive. Preimmigration interferon-gamma release assay screening and postarrival rifampin treatment was preferred in deterministic analysis. We calculated cost per quality-adjusted life-year gained for migrants from countries with different TB incidences. Our analysis provides evidence of the cost-effectiveness of preimmigration LTBI screening for migrants to low-incidence countries. Coupled with research on sustainability, acceptability, and program implementation, these results can inform policy decisions.

The effectiveness and cost-effectiveness of screening for active tuberculosis among migrants in the EU/EEA: a systematic review

: The foreign-born population make up an increasing and large proportion of tuberculosis (TB) cases in European Union/European Economic Area (EU/EEA) low-incidence countries and challenge TB elimination efforts. Methods: We conducted a systematic review to determine effectiveness (yield and performance of chest radiography (CXR) to detect active TB, treatment outcomes and acceptance of screening) and a second systematic review on cost-effectiveness of screening for active TB among migrants living in the EU/EEA. Results: We identified six systematic reviews, one report and three individual studies that addressed our aims. CXR was highly sensitive (98%) but only moderately specific (75%). The yield of detecting active TB with CXR screening among migrants was 350 per 100,000 population overall but ranged widely by host country (110–2,340), migrant type (170–1,192), TB incidence in source country (19–336) and screening setting (220–1,720). The CXR yield was lower (19.6 vs 336/100,000) and the numbers needed to screen were higher (5,076 vs 298) among migrants from source countries with lower TB incidence (≤ 50 compared with ≥ 350/100,000). Cost-effectiveness was highest among migrants originating from high (> 120/100,000) TB incidence countries. The foreign-born had similar or better TB treatment outcomes than those born in the EU/EEA. Acceptance of CXR screening was high (85%) among migrants. Discussion: Screening programmes for active TB are most efficient when targeting migrants from higher TB incidence countries. The limited number of studies identified and the heterogeneous evidence highlight the need for further data to inform screening programmes for migrants in the EU/EEA.

The effectiveness and cost-effectiveness of screening for latent tuberculosis among migrants in the EU/EEA: a systematic review

Migrants account for a large and growing proportion of tuberculosis (TB) cases in low-incidence countries in the European Union/European Economic Area (EU/EEA) which are primarily due to reactivation of latent TB infection (LTBI). Addressing LTBI among migrants will be critical to achieve TB elimination. Methods: We conducted a systematic review to determine effectiveness (performance of diagnostic tests, efficacy of treatment, uptake and completion of screening and treatment) and a second systematic review on cost-effectiveness of LTBI screening programmes for migrants living in the EU/EEA. Results: We identified seven systematic reviews and 16 individual studies that addressed our aims. Tuberculin skin tests and interferon gamma release assays had high sensitivity (79%) but when positive, both tests poorly predicted the development of active TB (incidence rate ratio: 2.07 and 2.40, respectively). Different LTBI treatment regimens had low to moderate efficacy but were equivalent in preventing active TB. Rifampicin-based regimens may be preferred because of lower hepatotoxicity (risk ratio = 0.15) and higher completion rates (82% vs 69%) compared with isoniazid. Only 14.3% of migrants eligible for screening completed treatment because of losses along all steps of the LTBI care cascade. Limited economic analyses suggest that the most cost-effective approach may be targeting young migrants from high TB incidence countries. Discussion: The effectiveness of LTBI programmes is limited by the large pool of migrants with LTBI, poorly predictive tests, long treatments and a weak care cascade. Targeted LTBI programmes that ensure high screening uptake and treatment completion will have greatest individual and public health benefit.

Medical care for migrant children in Europe: a practical recommendation for first and follow-up appointments

Between 2015 and 2017, an estimated 200,000 to 400,000 children were seeking asylum each year in EU/EEA countries. As access to high-quality health care is important, we collected and compared current recommendations across Europe for a consensus recommendation on medical care for migrant (asylum-seeking and refugee) children. Existing recommendations were collected from published literature and identified through national representatives from paediatric societies of 31 EU/EEA countries through the European Academy of Paediatrics (EAP). Recommendations were systematically extracted and collected in a database. Those mentioned in at least one recommendation were evaluated for inclusion, and evidence on recommendations was specifically identified in literature searches focused on recent evidence from Europe. For eight EU/EEA countries, a national recommendation was identified. Growth and development, vision and hearing impairment, skin and dental problems, immunisations, anaemia, micronutrient deficiency, helminths, hepatitis B and C, human immunodeficiency virus, malaria, schistosomiasis, syphilis, tuberculosis, mental health disorder and sexual health were most frequently mentioned and therefore selected for inclusion in the recommendation.Conclusion: The current document includes general recommendations on ethical standards, use of interpreters and specific recommendations for prevention or early detection of communicable and non-communicable diseases. It may serve as a tool to ensure the fundamental right that migrant children in Europe receive a comprehensive, patient-centred health care.

Demographic predictors of active tuberculosis in people migrating to British Columbia, Canada: a retrospective cohort study

BACKGROUND

Canadian tuberculosis (TB) guidelines recommend targeting postlanding screening for and treatment of latent tuberculosis infection (LTBI) in people migrating to Canada who are at increased risk for TB reactivation. Our objectives were to calculate robust longitudinal estimates of TB incidence in a cohort of people migrating to British Columbia, Canada, over a 29-year period, and to identify groups at highest risk of developing TB based on demographic characteristics at time of landing.

METHODS

We included all individuals (n = 1 080 908) who became permanent residents of Canada between Jan. 1, 1985, and Dec. 31, 2012, and were resident in BC at any time between 1985 and 2013. Multiple administrative databases were linked to the provincial TB registry. We used recursive partitioning models to identify populations with high TB yield.

RESULTS

Active TB was diagnosed in 2814 individuals (incidence rate 24.2/100 000 person-years). Demographic factors (live-in caregiver, family, refugee immigration classes; higher TB incidence in country of birth; and older age) were strong predictors of TB incidence in BC, with elevated rates continuing many years after entry into the cohort. Recursive partitioning identified refugees 18-64 years of age from countries with a TB incidence greater than 224/100 000 population as a high-yield group, with 1% developing TB within the first 10 years.

INTERPRETATION

These findings support recommendations in Canadian guidelines to target postlanding screening for and treatment of LTBI in adult refugees from high-incidence countries. Because high-yield populations can be identified at entry via demographic data, screening at this point may be practical and high-impact, particularly if the LTBI care cascade can be optimized.

The problem with defining foreign birth as a risk factor in tuberculosis epidemiology studies

OBJECTIVE

To examine how stratifying persons born outside Canada according to tuberculosis (TB) incidence in their birth country and other demographic factors refines our understanding of TB epidemiology and local TB transmission.

BACKGROUND

Population-level TB surveillance programs and research studies in low incidence settings often report all persons born outside the country in which the study is conducted as "foreign-born"-a single label for a highly diverse population with variable TB risks. This may mask important TB epidemiologic trends and not accurately reflect local transmission patterns.

METHODS

We used population-level data from two large cohorts in British Columbia (BC), Canada: an immigration cohort (n = 337,492 permanent residents to BC) and a genotyping cohort (n = 2290 culture-confirmed active TB cases). We stratified active TB case counts, incidence rates, and genotypic clustering (an indicator of TB transmission) in BC by birth country TB incidence, age at immigration, and years since arrival.

RESULTS

Persons from high-incidence countries had a 12-fold higher TB incidence than those emigrating from low-incidence settings. Estimates of local transmission, as captured by genotyping, versus reactivation of latent TB infection acquired outside Canada varied when data were stratified by birthplace TB incidence, as did patient-level characteristics of individuals in each group, such as age and years between immigration and diagnosis.

CONCLUSION

Categorizing persons beyond simply "foreign-born", particularly in the context of TB epidemiologic and molecular data, is needed for a more accurate understanding of TB rates and patterns of transmission.

Using country of origin to inform targeted tuberculosis screening in asylum seekers: a modelling study of screening data in a German federal state, 2002-2015

BACKGROUND

Screening programmes for tuberculosis (TB) among immigrants rarely consider the heterogeneity of risk related to migrants' country of origin. We assess the performance of a large screening programme in asylum seekers by analysing (i) the difference in yield and numbers needed to screen (NNS) by country and WHO-reported TB burden, (ii) the possible impact of screening thresholds on sensitivity, and (iii) the value of WHO-estimated TB burden to improve the prediction accuracy of screening yield.

METHODS

We combined individual data of 119,037 asylum seekers screened for TB in Germany (2002-2015) with TB estimates of the World Health Organization (WHO) (1990-2014) for their 81 countries of origin. Adjusted rate ratios (aRR) and 95% credible intervals (CrI) of the observed yield of screening were calculated in Bayesian Poisson regression models by categories of WHO-estimated TB incidence. We assessed changes in sensitivity depending on screening thresholds, used WHO TB estimates as prior information to predict TB in asylum seekers, and modelled country-specific probabilities of numbers needed to screen (NNS) conditional on different screening thresholds.

RESULTS

The overall yield was 82 per 100,000 and the annual yield ranged from 44.1 to 279.7 per 100,000. Country-specific yields ranged from 10 (95%- CrI: 1-47) to 683 (95%-CrI: 306-1336) per 100,000 in Iraqi and Somali asylum seekers, respectively. The observed yield was higher in asylum seekers from countries with a WHO-estimated TB incidence > 50 relative to those from countries ≤50 per 100,000 (aRR: 4.17, 95%-CrI: 2.86-6.59). Introducing a threshold in the range of a WHO-estimated TB incidence of 50 and 100 per 100,000 resulted in the lowest "loss" in sensitivity. WHO's TB prevalence estimates improved prediction accuracy for eight of the 11 countries, and allowed modelling country-specific probabilities of NNS.

CONCLUSIONS

WHO's TB data can inform the estimation of screening yield and thus be used to improve screening efficiency in asylum seekers. This may help to develop more targeted screening strategies by reducing uncertainty in estimates of expected country-specific yield, and identify thresholds with lowest loss in sensitivity. Further modelling studies are needed which combine clinical, diagnostic and country-specific parameters.

Tuberculosis screening for prospective migrants to high-income countries: systematic review of policies

OBJECTIVE

To compare predeparture tuberculosis (TB) screening policies, including screening criteria and screening tests, and visa requirements for prospective migrants to high-income countries that have low to intermediate TB incidence and high immigration.

STUDY DESIGN

Systematic review of policy documents.

METHODS

We systematically identified high-income, high net-migration countries with an estimated TB incidence of <30 per 100,000. After initial selection, this yielded 15 countries which potentially had TB screening policies. We performed a systematic search of governmental and official visa services' websites for these countries to identify visa information and policy documents for prospective migrants. Results were summarized, tabulated, and compared.

RESULTS

Programs to screen for active TB were identified in all 15 countries, but screening criteria and screening tests varied substantially between countries. Prospective migrants' country of origin represented an initial assessment criterion which generally focused on elevated TB incidence based on World Health Organization data but also focused on the countries of origin that sent the most migrants, and this varied between destination countries. Specific categories of migrants represented a second assessment criterion that focused on duration of stay and reasons for migration; the focus of which showed variation between the destination countries. Specific screening tests including medical examination and chest X-rays were used as the final stage of assessment, and there were differences between which tests were used between the destination countries.

CONCLUSIONS

Current approaches to migrant TB screening are inconsistent in their approach and implementation. While this variation might reflect adaptation to local public health situations, it could also indicate uncertainty concerning optimal strategies. Comparative research studies are needed to define the most effective and efficient methods for TB screening of migrants.

Estimating the prevalence of latent tuberculosis in a low-incidence setting: Australia

Migration is a key driver of tuberculosis (TB) in many low-incidence settings, with the majority of TB cases attributed to reactivation of latent TB (LTBI) acquired overseas. A greater understanding of LTBI risk in heterogeneous migrant populations would aid health planning. We aimed to estimate the LTBI prevalence and distribution among locally born and overseas-born Australians.

Annual risks of TB infection estimates were applied to population cohorts (by country of birth, year of arrival and age) in Australian census data in 2006, 2011 and 2016.

Both the absolute number and proportion of Australian residents with LTBI increased from 4.6% (interquartile range (IQR) 4.2–5.2%) in 2006 to 5.1% (IQR 4.7–5.5%) in 2016, due to the increasing proportion of the population born overseas (23.8% in 2006 to 28.3% in 2016). Of all residents estimated to have LTBI in 2016; 93.2% were overseas born, 21.6% were aged <35 years and 34.4% had migrated to Australia since 2007.

The overall prevalence of LTBI in Australia is low. Some residents, particularly migrants from high-incidence settings, may have considerably higher risk of LTBI, and these findings allow for tailored public health interventions to reduce the risk and impact of future TB disease.

Improving access to multi-drug resistant tuberculosis diagnostic and health services for refugees and migrants

By the end of 2017, an estimated 68.5 million people were displaced from their homes worldwide, of whom 25.4 million were refugees. The transmission and globalization of multi-drug resistant tuberculosis during refugee migration is a now priority issue in the public health agenda. Political and scientific commitment at the highest national and international levels will be critical to intensifying action in promoting improved health services for migrants and refugees.

Nationwide surveillance algorithms for tuberculosis among immigrant workers from highly endemic countries following pre-entry screening in Taiwan

Background

This cross-sectional study was retrospectively performed to assess the trend of tuberculosis (TB) among Taiwan’s immigrant workers from highly TB-endemic countries under an intervention of conducting a 4-round follow-up (at 0–3 days and 6, 18, and 30 months post-migration) screening program with initial chest X-ray (CXR) following an overseas, pre-entry normal CXR.

Methods

The immigrant workers with TB disease enrolled in the Taiwan TB registry database in 2011–2014 were analyzed and linked to an immigrant worker physical exam database to stratify TB case categories of actively screened or not for comparison.

Results

Following pre-entry screening for the admission of CXR-normal immigrant workers from highly endemic countries, the overall TB incidence of 70.6–128.6/100,000 person-years resulted either from a subsequent series of 4-round post-entry active screenings or misalliance algorithms, including passive diagnostics for the illness. Overall, the TB relative risk based on incidence in the immigrant working population was 2.2- to 5.5-fold greater than that among corresponding age Taiwanese, with 14.3% (15.5/100,000 person-years) sputum-smear-positive pulmonary TB (SS+ PTB), 74.2% (80.8/100,000 person-years) sputum-smear-negative (SS-) PTB, and 7.8% (8.5/100,000 person-years) only extra-pulmonary TB (EPTB). Regarding the clinical characteristics, 55.5% TB cases – identified through passive illness diagnostics vs. 44.5% TB cases actively identified through mandatory screenings, were higher in SS+ PTB (adjusted odds Ratio (aOR): 1.5, 95% CI: 1.1–2.0, P = 0.008), higher in SC+ PTB (aOR: 1.4, 95% CI: 1.1–1.7, P = 0.004), higher in concurrent extra-pulmonary TB (aOR: 8.9, CI: 4.5–7.4, P < 0.001), and higher in normal CXR TB (aOR: > 100, CI: 0- > 100, P = 0.908). The TB yields of 3rd- to 4th-round screenings were higher than those of 1st- and 2nd-round screenings and ranged from 52.6–65.3 cases per 100,000 screenings in 2013–2014.

Conclusions

The multiple post-entry TB screenings with initial CXR for high-risk immigrants could actively reduce TB transmission by finding SS- TB cases at early stages. The TB yields at post-entry 3rd- to 4th-round screenings might imply a persistent reactivation of latent TB. Adding more sensitive, economical screenings and preventive treatments for latent TB infection is a comprehensive approach for accelerating TB elimination.

Infectious disease testing of UK-bound refugees: a population-based, cross-sectional study

BACKGROUND

The UK, like a number of other countries, has a refugee resettlement programme. External factors, such as higher prevalence of infectious diseases in the country of origin and circumstances of travel, are likely to increase the infectious disease risk of refugees, but published data is scarce. The International Organization for Migration carries out and collates data on standardised pre-entry health assessments (HA), including testing for infectious diseases, on all UK refugee applicants as part of the resettlement programme. From this data, we report the yield of selected infectious diseases (tuberculosis (TB), HIV, syphilis, hepatitis B and hepatitis C) and key risk factors with the aim of informing public health policy.

METHODS

We examined a large cohort of refugees (n = 18,418) who underwent a comprehensive pre-entry HA between March 2013 and August 2017. We calculated yields of infectious diseases stratified by nationality and compared these with published (mostly WHO) estimates. We assessed factors associated with case positivity in univariable and multivariable logistic regression analysis.

RESULTS

The number of refugees included in the analysis varied by disease (range 8506-9759). Overall yields were notably high for hepatitis B (188 cases; 2.04%, 95% CI 1.77-2.35%), while yields were below 1% for active TB (9 cases; 92 per 100,000, 48-177), HIV (31 cases; 0.4%, 0.3-0.5%), syphilis (23 cases; 0.24%, 0.15-0.36%) and hepatitis C (38 cases; 0.41%, 0.30-0.57%), and varied widely by nationality. In multivariable analysis, sub-Saharan African nationality was a risk factor for several infections (HIV: OR 51.72, 20.67-129.39; syphilis: OR 4.24, 1.21-24.82; hepatitis B: OR 4.37, 2.91-6.41). Hepatitis B (OR 2.23, 1.05-4.76) and hepatitis C (OR 5.19, 1.70-15.88) were associated with history of blood transfusion. Syphilis (OR 3.27, 1.07-9.95) was associated with history of torture, whereas HIV (OR 1521.54, 342.76-6754.23) and hepatitis B (OR 7.65, 2.33-25.18) were associated with sexually transmitted infection. Syphilis was associated with HIV (OR 10.27, 1.30-81.40).

CONCLUSIONS

Testing refugees in an overseas setting through a systematic HA identified patients with a range of infectious diseases. Our results reflect similar patterns found in other programmes and indicate that the yields for infectious diseases vary by region and nationality. This information may help in designing a more targeted approach to testing, which has already started in the UK programme. Further work is needed to refine how best to identify infections in refugees, taking these factors into account.

Screening for tuberculosis in migrants and visitors from high-incidence settings: present and future perspectives

In most settings with a low incidence of tuberculosis (TB), foreign-born people make up the majority of TB cases, but the distribution of the TB risk among different migrant populations is often poorly quantified. In addition, screening practices for TB disease and latent TB infection (LTBI) vary widely. Addressing the risk of TB in international migrants is an essential component of TB prevention and care efforts in low-incidence countries, and strategies to systematically screen for, diagnose, treat and prevent TB among this group contribute to national and global TB elimination goals.This review provides an overview and critical assessment of TB screening practices that are focused on migrants and visitors from high to low TB incidence countries, including pre-migration screening and post-migration follow-up of those deemed to be at an increased risk of developing TB. We focus mainly on migrants who enter the destination country via application for a long-stay visa, as well as asylum seekers and refugees, but briefly consider issues related to short-term visitors and those with long-duration multiple-entry visas. Issues related to the screening of children and screening for LTBI are also explored.

A molecular epidemiological analysis of tuberculosis trends in South Korea

Molecular epidemiological data are needed to assess tuberculosis (TB)-management policy outcomes in South Korea. IS6110 restriction fragment-length polymorphism (IS6110-RFLP) and mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR) analyses are major molecular epidemiological tools for investigating the transmission or reactivation of active TB. Here, we determined trends in the clustering rate (i.e., the prevalence of Mycobacterium tuberculosis isolates with identical genotype patterns) of active TB and related differences between the 1990s and 2000s in Korea. M. tuberculosis isolates (1,007) of nationwide origins were analyzed by IS6110-RFLP and 24-locus standardized MIRU-VNTR genotyping. The clustering rate was measured by IS6110-RFLP, 24-locus MIRU-VNTR, and both analytical methods in combination. IS6110-RFLP, 24-locus MIRU-VNTR typing, and the combined method revealed 882, 754, and 983 distinct profiles; 809, 651, and 961 unique isolates; and 198, 356, and 46 clustered isolates grouped into 73, 103, and 22 clusters, respectively. In addition, we confirmed that the clustering rates in the 2000s decreased by 11.2%, 2.1%, and 3.1% relative to that in the 1990s using the three methods, respectively. Furthermore, in multivariate analysis, the younger-age group (<30) clustered more frequently than the older-age group (>50), based on all the three methods. Our study is the first report to provide nationwide molecular epidemiological information on TB in Korea.

T-SPOT.TB Performance in Routine Pediatric Practice in a Low TB Burden Setting

BACKGROUND

The T-SPOT.TB, an interferon-gamma release assay, is an indirect test of Mycobacterium tuberculosis infection. Due to sparse and conflicting evidence, the use of interferon-gamma release assay is limited in young and HIV-infected children. We determined the prevalence of invalid, borderline, positive and negative results and associations with key demographic variables during routine pediatric use in a low tuberculosis burden setting.

METHODS

For pediatric samples received at Oxford Diagnostic Laboratories between 2010 and 2015, the associations between initial test outcome and demographics were estimated by bivariate analysis and logistic regression.

RESULTS

A total of 44,289 samples (median age 12.5 years; interquartile range 7.7-15.5), including 5057 samples (11.6%) from children under 5 years old, were received from 46 U.S. states, Washington, DC and Puerto Rico. A total of 592 samples (1.3%) could not be tested. T-SPOT.TB positivity was strongly correlated (r = 0.60; P < 0.0001) with state TB incidence. Compared with negative results, positive results were more likely in samples from older children (P < 0.0001), public health clinics (P < 0.0001) and rural locations (P = 0.005). Although infrequent (0.6%), invalid results were more common in samples collected at HIV clinics (odds ratio = 2.5, 95% confidence interval: 1.3-4.9) and from younger children (P = 0.03). These invalid results were more likely due to a robust nil (negative) control response rather than a weak mitogen (positive) control response.

CONCLUSIONS

The T-SPOT.TB test correlated strongly with well-recognized risk factors for tuberculosis infection and provided evaluable results in 98% of children. To optimize the impact of testing on clinical decision making and patient outcomes, local epidemiology and individual patient risk should be considered when incorporating IGRAs into pediatric guidelines.

Monitoring and managing antibiotic resistance in refugee children

INTRODUCTION

The past decade the Middle East and Southeastern Europe have witnessed an enormous movement of refugees due to the Syrian war and conflicts in Asia and Africa. Although carriage of and infections with multi-drug resistant (MDR) pathogens in refugees have been reported, pediatric data are scarce. Areas covered: MDR bacterial carriage and infections, and MDR-tuberculosis (TB) in refugee children from 2010. Expert commentary: High MDR carriage rates in refugee children are attributed to high pre-civil war MDR rates, war-damaged infrastructure and healthcare systems, and poor hygiene conditions. Currently there are no international guidelines about MDR screening in refugee children. Given the medical importance of MDRs, challenging therapeutics and risk of importation in non/low-endemic countries, we recommend routine screening and contact isolation upon hospitalization of refugees. TB, including MDR-TB, is highly-endemic in many Asian and African countries, however, current data in refugee children are lacking. TB Screening in refugees is widely implemented but there is no consensus on methods and target populations. Coordinated TB detection and treatment, use of rapid molecular tests and drug-susceptibility testing, better access to healthcare, cross border TB care collaboration, and protection from deportation while on treatment should be integrated parts of TB control and prevention.

Prevention and assessment of infectious diseases among children and adult migrants arriving to the European Union/European Economic Association: a protocol for a suite of systematic reviews for public health and health systems

INTRODUCTION

The European Centre for Disease Prevention and Control is developing evidence-based guidance for voluntary screening, treatment and vaccine prevention of infectious diseases for newly arriving migrants to the European Union/European Economic Area. The objective of this systematic review protocol is to guide the identification, appraisal and synthesis of the best available evidence on prevention and assessment of the following priority infectious diseases: tuberculosis, HIV, hepatitis B, hepatitis C, measles, mumps, rubella, diphtheria, tetanus, pertussis, poliomyelitis (polio), Haemophilus influenza disease, strongyloidiasis and schistosomiasis.

METHODS AND ANALYSIS

The search strategy will identify evidence from existing systematic reviews and then update the effectiveness and cost-effectiveness evidence using prospective trials, economic evaluations and/or recently published systematic reviews. Interdisciplinary teams have designed logic models to help define study inclusion and exclusion criteria, guiding the search strategy and identifying relevant outcomes. We will assess the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

ETHICS AND DISSEMINATION

There are no ethical or safety issues. We anticipate disseminating the findings through open-access publications, conference abstracts and presentations. We plan to publish technical syntheses as GRADEpro evidence summaries and the systematic reviews as part of a special edition open-access publication on refugee health. We are following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols reporting guideline. This protocol is registered in PROSPERO: CRD42016045798.

Factors Influencing the Accuracy of Infectious Disease Reporting in Migrants: A Scoping Review

We conducted a scoping review of literature to improve our understanding of the accuracy of infectious disease monitoring in migrants in the Europe. We searched PubMed for papers relevant to the topic including: case reports, observational and experimental studies, reviews, guidelines or policy documents; published after 1994. We identified 532 papers, 27 of which were included in the review. Legislation and right to access health care influence both the accuracy of rates and risk measures under estimating the at risk population, i.e., the denominator. Furthermore, the number of reported cases, i.e., the numerator, may also include cases not accounted for in the denominator. Both biases lead to an overestimated disease occurrence. Restriction to healthcare access and low responsiveness may cause under-detection of cases, however a quantification of this phenomenon has not been produced. On the contrary, screening for asymptomatic diseases increases ascertainment leading to increased detection of cases. Incompleteness of denominator data underestimates the at-risk population. In conclusion, most studies show a lower probability of under-reporting infectious diseases in migrants compared with native populations.

Yield of active screening for tuberculosis among asylum seekers in Germany: a systematic review and meta-analysis

All asylum seekers in Germany undergo upon-entry screening for tuberculosis TB, but comprehensive evidence on the yield is lacking. We compared the national estimates with the international literature in a systematic review and meta-analysis of studies reporting the yield of TB, defined as the fraction of active TB cases detected among asylum seekers screened in Germany upon entry. We searched 11 national and international databases for empirical studies and the internet for grey literature published in English or German without restrictions on publication time. Among 1,253 screened articles, we identified six articles reporting the yield of active TB based on German data, ranging from 0.72 (95% confidence interval (CI): 0.45-1.10) to 6.41 (95% CI: 4.19-9.37) per 1,000 asylum seekers. The pooled estimate across all studies was 3.47 (95% CI: 1.78-5.73; I2 = 94.9%; p < 0.0001) per 1,000 asylum seekers. This estimate was in line with international evidence (I2 = 0%; p for heterogeneity 0.55). The meta-analysis of available international estimates resulted in a pooled yield of 3.04 (95% CI: 2.24-3.96) per 1,000. This study provides an estimate across several German federal states for the yield of TB screening in asylum seekers. Further research is needed to develop more targeted screening programmes.

Migration to middle-income countries and tuberculosis-global policies for global economies

Background

International migration to middle-income countries is increasing and its health consequences, in particular increasing transmission rates of tuberculosis (TB), deserve consideration. Migration and TB are a matter of concern in high-income countries and targeted screening of migrants for active and latent TB infection is a main strategy to manage risk and minimize transmission. In this paper, we discuss some aspects of TB control and migration in the context of middle-income countries, together with the prospect of responding with equitable and comprehensive policies.

Main body

TB rates in middle-income countries remain disproportionally high among the poorest and most vulnerable groups in large cities where most migrant populations are concentrated. Policies that tackle migrant TB in high-income countries may be inadequate for middle-income countries because of their different socio-economic and cultural scenarios. Strategies to control TB in these settings must take into account the characteristics of middle-income countries and the complexity of TB as a disease of poverty. Intersectoral policies of social protection such as cash-transfer programs help reducing poverty and improving health in vulnerable populations. We address the development of new approaches to improve well-established strategies including contact tracing and active and latent TB screening as an ‘add on’ to the existing health care guidelines of conditional cash transfer programs. In addition, we discuss how it might improve health and welfare among both poor migrants and locally-born populations. Authorities from middle-income countries should recognise that migrants are a vulnerable social group and promote cooperation efforts between sending and receiving countries for mitigation of poverty and prevention of disease in this group.

Conclusions

Middle-income countries have long sent migrants overseas. However, the influx of large migrant populations into their societies is relatively new and a growing phenomenon and it is time to set comprehensive goals to improve health among these communities. Conditional cash transfer policies with TB screening and strengthening of DOTS are some strategies that deserve attention. Reduction of social and health inequality among migrants should be incorporated into concerted actions to meet TB control targets.

Use of Transnational Services to Prevent Treatment Interruption in Tuberculosis-Infected Persons Who Leave the United States

Scale up of such services is possible and encouraged because of potential health gains and reduced healthcare costs.

A major problem resulting from interrupted tuberculosis (TB) treatment is the development of drug-resistant TB, including multidrug-resistant TB (MDR TB), a more deadly and costly-to-treat form of the disease. Global health systems are not equipped to diagnose and treat the current burden of MDR TB. TB-infected foreign visitors and temporary US residents who leave the country during treatment can experience treatment interruption and, thus, are at greater risk for drug-resistant TB. Using epidemiologic and demographic data, we estimated TB incidence among this group, as well as the proportion of patients referred to transnational care–continuity and management services during relocation; each year, ≈2,827 visitors and temporary residents are at risk for TB treatment interruption, 222 (8%) of whom are referred for transnational services. Scale up of transnational services for persons at high risk for treatment interruption is possible and encouraged because of potential health gains and reductions in healthcare costs for the United States and receiving countries.

Relation between BCG vaccine scar and an interferon-gamma release assay in immigrant children with "positive" tuberculin skin test (≥10 mm)

Background

Immigrants from countries with high incidence of tuberculosis (TB) are usually offered screening when they arrive to low incidence countries. The tuberculin skin test (TST) is often used. The interferon gamma release assays (IGRAs) are more specific and not affected by BCG vaccination. The aims of this study were 1. To see if there if there is a correlation between a positive IGRA (QFT) and presence of a BCG scar in children with TST ≥10 mm, 2. To compare the TST diameter with QFT result, 3. To see if chest X-ray can be omitted in QFT negative children despite TST ≥10 mm.

Methods

762 healthy children/adolescents (median age 14 years) arriving to Gothenburg and surroundings with TST ≥10 mm were tested with QFT.

Results

A total of 163/492 (33 %) children with BCG scar had positive QFT, whereas 205/270 (76 %) without BCG scar had positive QFT (p < 0.0001). The median TST was 12 mm in QFT negative and 18 mm in QFT positive children (p < 0.0001) but with considerable overlap. Median TST was the same (12 mm) in QFT negative children with and without BCG scar. Among the QFT positive children 25/368 had chest X-ray changes compared to 2/393 among the QFT negative children (p < 0.0007).

Conclusions

Previous BCG vaccination had an effect on the TST diameter so an IGRA is recommended to diagnose latent TB. Using only TST for screening of latent TB would lead to overdiagnosis. The TST diameter was larger in QFT positive than in QFT negative children but could not predict QFT in the individual patient. Chest X ray contributes little to the diagnosis of TB in QFT negative children but can not be omitted because of late seroconversion of QFT in some patients.

Trial registration

Not applicable.

Multidrug-resistant tuberculosis and migration to Europe

Multidrug-resistant tuberculosis (MDR-TB) in low-incidence countries in Europe is more prevalent among migrants than the native population. The impact of the recent increase in migration to EU and EEA countries with a low incidence of TB (<20 cases per 100 000) on MDR-TB epidemiology is unclear. This narrative review synthesizes evidence on MDR-TB and migration identified through an expert panel and database search. A significant proportion of MDR-TB cases in migrants result from reactivation of latent infection. Refugees and asylum seekers may have a heightened risk of MDR-TB infection and worse outcomes. Although concerns have been raised around 'health tourists' migrating for MDR-TB treatment, numbers are probably small and data are lacking. Migrants experience significant barriers to testing and treatment for MDR-TB, exacerbated by increasingly restrictive health systems. Screening for latent MDR-TB is highly problematic because current tests cannot distinguish drug-resistant latent infection, and evidence-based guidance for treatment of latent infection in contacts of MDR patients is lacking. Although there is evidence that transmission of TB from migrants to the general population is low-it predominantly occurs within migrant communities-there is a human rights obligation to improve the diagnosis, treatment and prevention of MDR-TB in migrants. Further research is needed into MDR-TB and migration, the impact of screening on detection or prevention, and the potential consequences of failing to treat and prevent MDR-TB among migrants in Europe. An evidence-base is urgently needed to inform guidelines for effective approaches for MDR-TB management in migrant populations in Europe.

Active Tuberculosis Case Finding Interventions Among Immigrants, Refugees and Asylum Seekers in Italy

In Italy tuberculosis (TB) is largely concentrated in vulnerable groups such as migrants and in urban settings. We analyzed three TB case finding interventions conducted at primary centers and mobile clinics for regular/irregular immigrants and refugees/asylum seekers performed over a four-year period (November 2009-March 2014) at five different sites in Rome and one site in Milan, Italy. TB history and presence of symptoms suggestive of active TB were investigated by verbal screening through a structured questionnaire in migrants presenting for any medical condition to out-patient and mobile clinics. Individuals reporting TB history or symptoms were referred to a TB clinic for diagnostic workup. Among 6347 migrants enrolled, 891 (14.0%) reported TB history or symptoms suggestive of active TB and 546 (61.3%) were referred to the TB clinic. Of them, 254 (46.5%) did not present for diagnostic evaluation. TB was diagnosed in 11 individuals representing 0.17% of those screened and 3.76% of those evaluated. The overall yield of this intervention was in the range reported for other TB screening programs for migrants, although we recorded an unsatisfactory adherence to diagnostic workup. Possible advantages of this intervention include low cost and reduced burden of medical procedures for the screened population.

Reactivation tuberculosis: role of surveillance

The incidence and death rates from tuberculosis (TB) have declined through concerted efforts in the diagnosis and treatment of active disease. Despite this, 9.6 million new cases and 1.1 million deaths in 2014 are unacceptably high. To decrease the rates of TB further, the huge number of persons with latent TB infection (LTBI) from whom new cases will arise has to be addressed with a sense of priority. Identifying the highest risk groups and providing effective treatment has been shown to decrease active TB. Further research to refine the predictors of reactivation and shorter effective treatments are urgently needed. Implementing intensified case finding, testing and treatment for LTBI will require continued investment in health care capacity at multiple levels.