Screening for latent tuberculosis infection among undocumented immigrants in Swiss healthcare centres; a descriptive exploratory study

Initiation and completion of treatment for latent tuberculosis infection in migrants globally: a systematic review and meta-analysis

Background

Latent tuberculosis infection (LTBI) is one of the most prevalent infections globally and can lead to the development of active tuberculosis disease. In many low-burden countries, LTBI is concentrated within migrant populations often because of a higher disease burden in the migrant's country of origin. National programmes consequently focus on screening and treating LTBI in migrants to prevent future tuberculosis cases; however, how effective these programmes are is unclear. We aimed to assess LTBI treatment initiation and outcomes among migrants, and the factors that influence both.

Methods

For this systematic review and meta-analysis, we searched Embase, MEDLINE, and Global Health, and manually searched grey literature from Jan 1, 2000, to April 21, 2020. We included primary research articles reporting on LTBI treatment initiation or completion, or both, in migrants and excluded articles in which data were not stratified by migrant status, or in which the data were related to outcomes before 2000. There were no geographical or language restrictions. All included studies were quality appraised using recognised tools depending on their design, and we assessed the heterogeneity of analyses using I². We extracted data on the numbers of migrants initiating and completing treatment. Our primary outcomes were LTBI treatment initiation and completion in migrants (defined as foreign-born). We used random-effects meta-regression to examine the influence of factors related to these outcomes. The study is registered with PROSPERO (CRD42019140338).

Findings

2199 publications were retrieved screened, after which 39 publications from 13 mostly high-income, low-burden countries were included in our analyses, with treatment initiation and completion data reported for 31 598 migrants positive for LTBI, with not all articles reporting the full pathway from initiation to completion. The pooled estimate for the true proportion of migrants testing positive who initiated treatment was 69% (95% CI 51–84; I²= 99·62%; 4409 of 8764). The pooled estimate for the true proportion of migrants on treatment in datasets, who subsequently completed it was 74% (95% CI = 66–81; I²= 99·19%; 15 516 of 25 629). Where data were provided for the entire treatment pathway, the pooled estimate for the true proportion of migrants who initiated and completed treatment after a positive test was only 52% (95% CI 40–64; I²= 98·90%; 3289 of 6652). Meta-regression showed that LTBI programmes are improving, with more recent reported data (2010–20) associated with better rates of treatment initiation and completion, with multiple complex factors affecting treatment outcomes in migrants.

Interpretation

Although our analysis highlights that LTBI treatment initiation and completion in migrants has improved considerably from 2010–20, there is still room for improvement, with drop out reported along the entire treatment pathway. The delivery of these screening and treatment programmes will require further strengthening if the targets to eradicate tuberculosis in low-incidence countries are to be met, with greater focus needed on engaging migrants more effectively in the clinic and understanding the diverse and unique barriers and facilitators to migrants initiating and completing treatment.

Funding

European Society of Clinical Microbiology and Infectious Diseases, the Rosetrees Trust, the National Institute for Health Research, and the Academy of Medical Sciences.

'Managing scarcity'- a qualitative study on volunteer-based healthcare for chronically ill, uninsured migrants in Berlin, Germany

OBJECTIVES

In Germany, healthcare for people lacking legal residency status and European Union citizens without health insurance is often provided by non-governmental organisations. Scientific studies assessing the situation of the patients with chronic diseases in this context are scarce. We aimed to characterise medical care for chronically ill migrants without health insurance and outline its possibilities and limitations from the treating physicians' perspective.

DESIGN

Qualitative semi-structured interviews; qualitative content analysis.

SETTING

Organisations and facilities providing healthcare for uninsured migrants: free clinics, medical practices and public health services.

PARTICIPANTS

14 physicians working regularly in healthcare for uninsured migrants.

RESULTS

Delayed contact to the healthcare system was frequently addressed in the interviews. Care was described as constrained by a scarcity of resources that often impedes adequate treatment for many conditions, most pronounced in the case of oncological diseases or chronic viral infections (HIV, hepatitis). For other chronic conditions such as cardiovascular diseases or diabetes, some diagnostics and basic medications were described as partially available, while management of complications or rehabilitative measures are frequently unfeasible. For the patients with mental health problems, attainability of psychotherapeutic treatment is reported as severely limited. Care is predominantly described as fragmented with limitations to information flow and continuity. Which level of care a patient receives appears to depend markedly on the respective non-governmental organisation and the individual commitment, subjective decisions and personal connections of the treating physician.

CONCLUSIONS

Restrictions in medical care for uninsured migrants have even more impact on chronically ill patients. Volunteer-based care often constitutes an inadequate compensation for regular access to the healthcare system, as it is strongly influenced by the limitation of its resources and its arbitrariness.

Compliance with Tuberculosis Screening in Irregular Immigrants

Tuberculosis (TB) is a serious public health problem in many regions of the world, especially in the poorest areas. For this reason, screening for active and latent forms must be considered when dealing with high-risk groups such as irregular immigrants in Western countries. We conducted a retrospective cohort study by recruiting subjects aged ≥15 years who underwent a tuberculin skin test at a dedicated National Health Service Centre in a northern Italian province between 1 January 2012 and 31 December 2013. These participants were followed up until 31 December 2016. We aimed at evaluating an experimental protocol for active and latent tuberculosis screening, focusing on patient compliance, feasibility, and capability to detect clinical forms of the disease. We enrolled 368 irregular immigrants, i.e., immigrants not having a valid residence permit and who were therefore not entitled to choose a general practitioner. In total, 90.22% of these completed all the steps for the screening of active TB, while 87.33% also undertook screening for the latent form of the disease. Homelessness, self-reported prostitution, female sex, and employment status adversely affected compliance. Chronic alcohol consumption was associated with increased risk of no beginning or interruption of the procedures. All of the five patients with active TB successfully completed the treatment. Overall, adherence to the screening program was high compared to other studies in immigrants, possibly owing to organizational factors such as the availability of cultural mediators, the network between the different health services, the presence of dedicated nursing staff and a free-of-charge service. In addition, selected vulnerable subgroups should be targeted using tailored screening and follow-up programs.

Health of undocumented migrants in primary care in Switzerland

Background

Undocumented migrants endure adverse living conditions while facing barriers to access healthcare. Evidence is lacking regarding their healthcare needs, notably in regards to chronic diseases. Our goal was to investigate health conditions in undocumented migrants attended in primary care setting.

Methods

This study was conducted at the primary care outpatient clinic, Geneva University Hospitals, Switzerland. We retrospectively recorded and coded all medical conditions of a random sample of 731 undocumented migrants using the International Classification of Primary Care, 2nd version (ICPC-2). We dichotomized conditions as chronic or non-chronic and considered multimorbidity in the presence of three or more chronic conditions.

Results

Participants originated from 72 countries and were mainly female (65.5%) with a mean age of 42.4 (standard deviation [SD]: 11.4) years. They presented a mean of 2.9 (SD: 2.1; range: 1–17) health conditions. In multivariable analysis, the number of conditions was associated with female gender (p = 0.011) and older age (p <0.001), but not with origin (p = 0.373). The body systems most frequently affected were endocrine, metabolic and nutritional (n = 386; 18.4%), musculoskeletal (n = 308, 14.7%) and digestive (n = 266, 12.8%). Hypertension (17.9%; 95% CI: 15.2%, 29.9%), obesity or overweight (16%; 95% CI: 13.4%, 18.9%) and gastric problems (14.1%; 95% CI: 11.6%, 16.8%) were most prevalent. Overall, 71.8% (95% CI: 68.5%, 75%) participants had at least one chronic condition while 20% (95% CI: 17.2%, 23.1%) had three or more. In multivariable analysis, age (p <0.001) was the only predictor of presenting at least one or three or more chronic conditions.

Conclusions

Undocumented migrants present multiple health problems in primary care settings and bear an important burden of chronic diseases. The extent of multimorbidity highlights the need to provide and facilitate the access to comprehensive and long-term primary healthcare services.

How effective are approaches to migrant screening for infectious diseases in Europe? A systematic review

Rates of migration to Europe, and within Europe, have increased in recent years, with considerable implications for health systems. Migrants in Europe face a disproportionate burden of tuberculosis, HIV, and hepatitis B and C, yet experience a large number of barriers to accessing statutory health care on arrival. A better understanding of how to deliver effective and cost-effective screening, vaccination, and health services to this group is now crucial. We did a systematic review to document and assess the effectiveness and cost-effectiveness of approaches used for infectious diseases screening, and to explore facilitators and barriers experienced by migrants to accessing screening programmes. Following PRISMA guidelines, we searched Embase, PubMed, PsychINFO, the Cochrane Library, and Web of Science (1989 to July 1, 2015, updated on Jan 1, 2018), with no language restrictions, and systematically approached experts across the European Union (EU) for grey literature. Inclusion criteria were primary research studies assessing screening interventions for any infectious disease in the migrant (foreign-born) population residing in EU or European Economic Area (EEA) countries. Primary outcomes were the following effectiveness indicators: uptake of screening, coverage, infections detected, and treatment outcomes. Of 4112 unique records, 47 studies met our inclusion criteria, from ten European countries (Belgium, Denmark, France, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the UK) encompassing 248 402 migrants. We found that most European countries screening migrants focus on single diseases only-predominantly active or latent tuberculosis infection-and specifically target asylum seekers and refugees, with 22 studies reporting on other infections (including HIV and hepatitis B and C). An infection was detected in 3·74% (range 0·00-95·16) of migrants. Latent tuberculosis had the highest prevalence across all infections (median 15·02% [0·35-31·81]). Uptake of screening by migrants was high (median 79·50% [18·62-100·00]), particularly in primary health-care settings (uptake 96·77% [76·00-100·00]). However, in 24·62% (0·12-78·99) of migrants screening was not completed and a final diagnosis was not made. Pooled data highlight high treatment completion in migrants (83·79%, range 0·00-100·00), yet data were highly heterogeneous for this outcome, masking important disparities between studies and infections, with only 54·45% (35·71-72·27) of migrants with latent tuberculosis ultimately completing treatment after screening. Coverage of the migrant population in Europe is low (39·29% [14·53-92·50]). Data on cost-effectiveness were scarce, but suggest moderate to high cost-effectiveness of migrant screening programmes depending on migrant group and disease targeted. European countries have adopted a variety of approaches to screening migrants for infections; however, these are limited in scope to single diseases and a narrow subset of migrants, with low coverage. More emphasis must be placed on developing innovative and sustainable strategies to facilitate screening and treatment completion and improve health outcomes, encompassing multiple key infections with consideration given to a wider group of high-risk migrants. Policy makers and researchers involved with global migration need to ensure a longer-term view on improving health outcomes in migrant populations as they integrate into health systems in host countries.

Prevalence of latent tuberculosis infection in Syrian refugees to Canada

OBJECTIVES

Canada has accepted more than 25,000 Syrian refugees fearing persecution in their homeland. Canadian guidelines recommend screening recent refugees from high incidence countries for tuberculosis (TB) and latent TB infection (LTBI). The prevalence of TB in this population is unknown. A refugee clinic in Edmonton presented a unique opportunity to estimate prevalence of TB and LTBI in Syrian refugees arriving in Canada.

METHODS

In January 2016, 100 consecutive Syrian refugees were screened for TB with clinical assessment and LTBI using QuantiFERON Gold In-Tube assay (QFT-GIT). Patients with positive QFT-GIT were referred to Edmonton Tuberculosis Clinic (ETBC) for evaluation and, if appropriate, offered prophylaxis.

RESULTS

No cases of active TB were found. Valid QFT-GIT were measured in 99 of 100 individuals and of these, nine (9%) were positive using a threshold concentration of blood interferon-γ greater than 0.35 IU/L. Eight of the nine patients attended follow-up appointments; of these, seven began LTBI prophylaxis and all seven (78%) completed same.

CONCLUSION

The 9% (95% confidence interval 3-15%) prevalence of LTBI was higher than expected in this population.

Emergency Room Visits by Uninsured Child and Adult Residents in Ontario, Canada: What Diagnoses, Severity and Visit Disposition Reveal About the Impact of Being Uninsured

Canadian immigrants can be without health insurance for many reasons but limited data exists regarding uninsured health outcomes. Uninsured Canadian residents were identified in the National Ambulatory Care Reporting System for all visits to emergency departments in Ontario, Canada between 2002/3 and 2010/11 (N = 44,489,750). Frequencies for main diagnoses, severity (triage), and visit disposition were compared. Ambulatory care sensitive conditions were identified in a 10 % subsample. The uninsured (N = 140,730; 0.32 %) were more likely to be diagnosed with mental health (insured: 3.48 %; uninsured: 10.47 %) or obstetric problems (insured: 2.69 %; uninsured: 5.56 %), be triaged into the two most severe categories (insured: 11.2 %; uninsured 15.6 %), leave untreated (insured: 3.1 %; uninsured: 5.4 %), or die (insured: 2.8 %; uninsured: 3.7 %). More ACSC visits were made by uninsured children and youth. Insurance status is associated with more serious health status on arrival to emergency departments and more negative visit outcomes.

Effect of Legal Status on the Early Treatment Outcomes of Migrants Beginning Combined Antiretroviral Therapy at an Outpatient Clinic in Milan, Italy

OBJECTIVE

In a setting of free access to HIV care, we compared the early treatment outcomes of HIV-infected undocumented migrants (UMs), documented migrants (DMs), and Italian subjects.

METHODS

The clinical data of 640 Italians and 245 migrants who started combined antiretroviral therapy (cART) at an HIV clinic in Milan, Italy, were reviewed. The migrants were mainly Latin Americans (83 DMs and 56 UMs) or sub-Saharan Africans (52 DMs and 11 UMs), but a minority were of other origin (33 DMs and 10 UMs). Retention in follow-up and HIV suppression were compared between UMs, DMs, and natives 12 months ± 90 days after start of cART.

RESULTS

There were no significant between-group differences in the stage of HIV infection at the start of cART or the type of regimen received. The Latin American DMs and UMs included a higher proportion of transgender women than the other ethnic groups (P < 0.001). The UMs were less frequently followed up after 12 months than the DMs and natives (P = 0.004) and were more frequently permanently lost to follow-up (P < 0.001). UM status was an independent predictor of lost to follow-up (adjusted odds ratio 8.05, P < 0.001). The DMs and UMs were less frequently HIV suppressed after 12 months than the natives (78% and 80.7% vs 90.5%, P = 0.001), and Latin American migrants were significantly less likely to be virologically suppressed than the natives (adjusted odds ratio 0.30, P = 0.001).

CONCLUSIONS

Despite their free access to cART, subgroups of migrants facing multiple levels of vulnerability still have difficulties in gaining optimal HIV care.

The cascade of care in diagnosis and treatment of latent tuberculosis infection: a systematic review and meta-analysis

BACKGROUND

WHO estimates that a third of the world's population has latent tuberculosis infection and that less than 5% of those infected are diagnosed and treated to prevent tuberculosis. We aimed to systematically review studies that report the steps from initial tuberculosis screening through to treatment for latent tuberculosis infection, which we call the latent tuberculosis cascade of care. We specifically aimed to assess the number of people lost at each stage of the cascade.

METHODS

We did a systematic review and meta-analysis of study-level observational data. We searched MEDLINE (via OVID), Embase, and Health Star for observational studies, published between 1946 and April 12, 2015, that reported primary data for diagnosis and treatment of latent tuberculosis infection. We did meta-analyses using random and fixed effects analyses to identify percentages of patients with latent tuberculosis infection completing each step in the cascade. We also estimated pooled proportions in subgroups stratified by different characteristics of interest to assess risk factors for losses.

RESULTS

We identified 58 studies, describing 70 distinct cohorts and 748 572 people. Steps in the cascade associated with greater losses included completion of testing (71·9% [95% CI 71·8-72·0] of people intended for screening), completion of medical evaluation (43·7% [42·5-44·9]), recommendation for treatment (35·0% [33·8-36·4]), and completion of treatment if started (18·8% [16·3-19·7]). Steps with fewer losses included receiving test results, referral for evaluation if test positive, and accepting to start therapy if recommended. Factors associated with fewer losses were immune-compromising medical indications, being part of contact investigations, and use of rifamycin-based regimens.

INTERPRETATION

We identify major losses at several steps in the cascade of care for latent tuberculosis infection. Improvements in management of latent tuberculosis will need programmatic approaches to address the losses at each step in the cascade.

FUNDERS

Canadian Institutes of Health Research.

The impact of migration on tuberculosis epidemiology and control in high-income countries: a review

Tuberculosis (TB) causes significant morbidity and mortality in high-income countries with foreign-born individuals bearing a disproportionate burden of the overall TB case burden in these countries. In this review of tuberculosis and migration we discuss the impact of migration on the epidemiology of TB in low burden countries, describe the various screening strategies to address this issue, review the yield and cost-effectiveness of these programs and describe the gaps in knowledge as well as possible future solutions.The reasons for the TB burden in the migrant population are likely to be the reactivation of remotely-acquired latent tuberculosis infection (LTBI) following migration from low/intermediate-income high TB burden settings to high-income, low TB burden countries.TB control in high-income countries has historically focused on the early identification and treatment of active TB with accompanying contact-tracing. In the face of the TB case-load in migrant populations, however, there is ongoing discussion about how best to identify TB in migrant populations. In general, countries have generally focused on two methods: identification of active TB (either at/post-arrival or increasingly pre-arrival in countries of origin) and secondly, conditionally supported by WHO guidance, through identifying LTBI in migrants from high TB burden countries. Although health-economic analyses have shown that TB control in high income settings would benefit from providing targeted LTBI screening and treatment to certain migrants from high TB burden countries, implementation issues and barriers such as sub-optimal treatment completion will need to be addressed to ensure program efficacy.

Restricted access to antiretroviral treatment for undocumented migrants: a bottle neck to control the HIV epidemic in the EU/EEA

Background

In the European Union/European Economic Area (EU/EEA), migrants from high-endemic countries are disproportionately affected by HIV. Between 2007 and 2012, migrants represented 39 % of reported HIV cases. There is growing evidence that a significant proportion of HIV acquisition among migrant populations occurs after their arrival in Europe.

Discussion

Migrants are confronted with multiple risk factors that shape patterns of population HIV susceptibility and vulnerability, which simultaneously affect HIV transmission. Undocumented migrants incur additional risks for contracting HIV due to limited access to adequate health care services, protection and justice, alongside insecure housing and employment conditions.

All EU/EEA countries have ratified a number of international and regional human rights instruments that enshrine access to health care as a human right that should be available to everyone without discrimination.

From a clinical and public health perspective, early HIV care and treatment is associated with viral suppression, improved health outcomes and reductions in transmission risks. A current challenge of the HIV epidemic is to reach the highest proportion of overall viral suppression among people living with HIV in order to impact on HIV transmission.

Although the majority of EU/EEA countries regard migrants as an important sub-population for their national responses to HIV, and despite the overwhelming evidence of the individual and public health benefits associated with HIV care and treatment, a significant number of EU/EEA countries do not provide antiretroviral treatment to undocumented migrants.

Summary

HIV transmission dynamics in migrant populations depend on the respective weight of all risk and vulnerability factors to which they are exposed, which act together in a synergistic way. People who are not linked to HIV care will continue to unwillingly contribute to the on-going transmission of HIV. Following the recommendations of the European Union Agency for Fundamental Rights, ensuring access to HIV-care for all sub-populations, including undocumented migrants, would fulfil the human rights of those populations and also strengthen the control of HIV incidence among those not currently able to access HIV care.

A systematic review on TST and IGRA tests used for diagnosis of LTBI in immigrants

BACKGROUND

High immigration rates from tuberculosis (TB) endemic countries to low-incidence countries have caused new TB guidelines in these countries to reconsider latent TB infection (LTBI) screening in these immigrants.

OBJECTIVES

We performed a systematic review with the primary outcome of evaluating the number of cases recommended LTBI treatment with the tuberculin skin test (TST) or interferon gamma release assay (IGRA). Secondary objectives were to examine prevalence of positive LTBI diagnostic tests stratified by age and incidence of TB in country of origin.

METHODS

We performed a systematic search of seven electronic databases for studies assessing TST and/or IGRA performance in immigrant populations to low incidence countries. Demographics, LTBI diagnosis, longitudinal TB development, and test result data were the primary data extracted from the studies. Prevalence of positive test data was stratified by age and country of origin. Studies were evaluated using a modified SIGN checklist for diagnostic studies. Data was compared using Fisher's exact test or χ (2) test, where appropriate.

RESULTS

Our literature search yielded 51 studies (n = 34 TST, n = 9 IGRA, n = 8 both). Recommendation of LTBI treatment was less common in those tested with an IGRA compared to TST (p < 0.0001), while long-term development of active TB appears higher in those with a positive IGRA. There was no difference in the sensitivity and specificity of the IGRA and TST for prevalent TB (p > 0.05). Prevalence of a positive test was significantly lower in those who were <18 years of age compared to those ≥18 years of age (p < 0.0001) and those from low TB incidence countries compared to high incidence countries (p < 0.0001) for both TST and IGRA. When comparing the two tests within the 2 subgroups: age and TB incidence in country of origin, the prevalence of positive results was significantly lower for the IGRA than the TST (p < 0.0001).

LIMITATIONS

The number of available studies evaluating the IGRA and longitudinal active TB development in those tested limits this study.

CONCLUSION

Prevalence of positive test results were significantly lower in immigrants who were tested with an IGRA, resulting in fewer immigrants being recommended for LTBI treatment compared to TST. Coupled with comparable performance for detecting prevalent TB cases, the IGRA appears to exhibit better specificity than the TST and may be preferred as the standard of care for detecting LTBI in immigrants moving to low TB incidence countries.

La Compleja Relación Entre Posición Socioeconómica, Estatus Migratorio y Resultados de Salud

INTRODUCTION

The relationship between socioeconomic position (SEP), migration and health is dynamic, difficult to predict, multifactorial and poorly studied in the Latin American region. Moreover, there are high levels of uncertainty about reasons, types, and consequences of migration to an individual, family, community, country of origin and the receiving country.

OBJECTIVE

To discuss the evidence about the complex relationship between SEP, migration and health outcomes.

RESULTS

According to international evidence available, migration has a direct impact on health outcomes in a population and, in turn, on public health policy decisions in each locality. The available evidence on this issue affects multiple parts of the social sciences. The "healthy migrant" effect is not consistently observed among immigrant populations, particularly after adjusting for PSE. Moreover, the immigrant population tends to assimilate in terms of risk factors and morbidity to the local population after about 10 years of stay in the foreign country. Migration has consequences for international relations, economic productive capacity of a country, inequality, demographic changes and health outcomes, to mention a few.

CONCLUSION

There is now the opportunity to generate better and more evidence longitudinal population-based around the relationship between SEP, migration status and health. This will contribute to reduce uncertainty about the health status of immigrants that is required for decision- making in public health in Chile and the region.

High rates of Mycobacterium tuberculosis among socially marginalized immigrants in low-incidence area, 1991-2010, Italy

Migration from low- and middle-income countries to high-income countries increasingly determines the severity of tuberculosis (TB) cases in the adopted country. Socially marginalized groups, about whom little is known, may account for a reservoir of TB among the immigrant populations. We investigated the rates of and risk factors for Mycobacterium tuberculosis transmission, infection, and disease in a cohort of 27,358 socially marginalized immigrants who were systematically screened (1991-2010) in an area of Italy with low TB incidence. Overall TB and latent TB infection prevalence and annual tuberculin skin testing conversion rates (i.e., incidence of new infection) were 2.7%, 34.6%, and 1.7%, respectively. Prevalence of both TB and latent TB infection and incidence of infection increased as a function of the estimated TB incidence in the immigrants' countries of origin. Annual infection incidence decreased with time elapsed since immigration. These findings have implications for control policy and immigrant screening in countries with a low prevalence of TB.

Sexual and reproductive health behaviors of undocumented migrants in Geneva: a cross sectional study

Undocumented migrants face major barriers in accessing prevention and health care. Whereas the association between low socioeconomic status and poor health is well documented only few studies have addressed specific health issues in undocumented migrants. The aim of the present study is to describe sexual and reproductive health behaviors of undocumented migrants in Geneva. This descriptive cross sectional study included consecutive undocumented migrants presenting from November 2007 to February 2008 to a health facility offering free access to health care to this population. Following informed consent, they completed a self administered questionnaire about their socio-demographic profile and sexual and reproductive health behaviors. A total of 384 patients were eligible for the study. 313 (82%) agreed to participate of which 77% (241 patients) completed the survey. Participants were mainly young, Latino-American, single, well-educated and currently working women. They had multiple partners and reported frequently engaging in sexual intercourse. Use of contraceptive methods and strategies of prevention against sexually transmitted infections (STI) were rare. Nearly half of the women had had at least one induced abortion and 40% had had an unplanned pregnancy. One in four participants reported a current or past STI or other genital infection. The results of our study suggest that undocumented migrants engage in frequent and high risk sexual intercourse with insufficient use of contraceptive methods and suboptimal strategies of prevention against STI. Our study underlines the real need for specific sexual and reproductive educational programs targeting this hard to reach population.

Screening of immigrants in the UK for imported latent tuberculosis: a multicentre cohort study and cost-effectiveness analysis

Background

Continuing rises in tuberculosis notifications in the UK are attributable to cases in foreign-born immigrants. National guidance for immigrant screening is hampered by a lack of data about the prevalence of, and risk factors for, latent tuberculosis infection in immigrants. We aimed to determine the prevalence of latent infection in immigrants to the UK to define which groups should be screened and to quantify cost-effectiveness.

Methods

In our multicentre cohort study and cost-effectiveness analysis we analysed demographic and test results from three centres in the UK (from 2008 to 2010) that used interferon-γ release-assay (IGRA) to screen immigrants aged 35 years or younger for latent tuberculosis infection. We assessed factors associated with latent infection by use of logistic regression and calculated the yields and cost-effectiveness of screening at different levels of tuberculosis incidence in immigrants' countries of origin with a decision analysis model.

Findings

Results for IGRA-based screening were positive in 245 of 1229 immigrants (20%), negative in 982 (80%), and indeterminate in two (0·2%). Positive results were independently associated with increases in tuberculosis incidence in immigrants' countries of origin (p=0·0006), male sex (p=0·046), and age (p<0·0001). National policy thus far would fail to detect 71% of individuals with latent infection. The two most cost-effective strategies were to screen individuals from countries with a tuberculosis incidence of more than 250 cases per 100 000 (incremental cost-effectiveness ratio [ICER] was £17 956 [£1=US$1·60] per prevented case of tuberculosis) and at more than 150 cases per 100 000 (including immigrants from the Indian subcontinent), which identified 92% of infected immigrants and prevented an additional 29 cases at an ICER of £20 819 per additional case averted.

Interpretation

Screening for latent infection can be implemented cost-effectively at a level of incidence that identifies most immigrants with latent tuberculosis, thereby preventing substantial numbers of future cases of active tuberculosis.

Funding

Medical Research Council and Wellcome Trust.

Tuberculosis in Europe: a problem of drug resistance or much more?

Tuberculosis has re-emerged as a public health concern in high-income countries in the last few decades. The European region accounts for only 5% of world TB cases. The incidence of new TB cases in Europe varies from very low rates in Scandinavian countries (six to eight cases/100,000 population) to rates as high as 231 cases/100,000 population in Tajikistan; the Russian Federation is eleventh among the 22 high-burden TB countries. The estimated detection rate of new sputum smear-positive pulmonary cases and the treatment success rate in 2007 were poor compared with other WHO regions: 51% of cases were diagnosed and 70% of them completed a full course of anti-TB therapy, which is still a long way from the World Health Assembly targets (detection of 70% of infectious cases and successful treatment of 85% of them). The low success rate is largely attributable to the increasing number of drug-resistant TB cases: Eastern European countries are among those with the highest rates of multidrug-resistant (MDR)-TB (TB resistant to rifampicin and isoniazid) in the world. By the end of September 2009, at least one case of extensively drug-resistant TB (named XDR-TB and defined as a MDR-TB strain with additional resistance to any fluoroquinolone, and to at least one of three injectable drugs used in anti-TB treatment) had been reported by 25 countries in the WHO European Region. In Western Europe, TB continues to cause disease among elderly native-born individuals, although high-risk groups including immigrants, prisoners, HIV-infected persons and drug addicts significantly contribute to the overall burden. Improved TB control in Europe requires a large coordinated effort by all stakeholders, including governments, governmental and non-governmental institutions, as well as the academic and private sectors and affected communities.

Undocumented migrants in Switzerland: geographical origin versus legal status as risk factor for tuberculosis

Undocumented migrants, meaning migrants without a legal residency permit, come to Geneva from countries with high tuberculosis (TB) incidence. We estimate here whether being undocumented is a determinant of TB, independently of origin. Cross-sectional study including undocumented migrants in a TB screening program in 2002; results were compared to 12,904 age and frequency matched participants in a general TB screening program conducted at various workplaces in Geneva, Switzerland from 1992 to 2002. A total of 206 undocumented migrants (36% male, 64% female, mean age 37.8 years (SD 11.8), 82.5% from Latin America) participated in the TB screening program. Compared to legal residents, undocumented migrants had an adjusted OR for TB-related fibrotic signs of 1.7 (95% CI 0.8;3.7). The OR of TB-related fibrotic signs for Latin American (vs. other) origin was 2.7 (95% CI 1.6;4.7) among legal residents and 5.5 (95% CI 2.8;10.8) among undocumented migrants. Chest X-ray screening identified a higher proportion of TB-related fibrotic signs among Latin Americans, independently of their residency status.

Evidence-based comparison of commercial interferon-gamma release assays for detecting active TB: a metaanalysis

Test accuracy of interferon-gamma release assays (IGRAs) for diagnosing TB differs when using older or precommercial tools and inconsistent diagnostic criteria. This metaanalysis critically appraises studies investigating sensitivity and specificity of the commercial T-Spot.TB and the QuantiFERON-TB Gold In-Tube Assay (QFT-IT) among definitely confirmed TB cases. We searched Medline, EMBASE, and Cochrane bibliographies of relevant articles. Sensitivities, specificities, and indeterminate rates were pooled using a fixed effect model. Sensitivity of the tuberculin skin test (TST) was evaluated in the context of IGRA studies. In addition, the rates of indeterminates of both IGRAs were assessed. The pooled sensitivity of TST was 70% (95% CI, 0.67-0.72) compared with 81% (95% CI, 0.78-0.83) for the QFT-IT and 88% (95% CI, 0.85-0.90) for the T-Spot.TB. Sensitivity increased to 84% (95%CI, 0.81-0.87) and 89% (95% CI, 0.86-0.91) for the QFT-IT and T-Spot.TB, respectively, when restricted to performance in developed countries. In contrast, specificity of the QFT-IT was 99% (95% CI, 0.98-1.00) vs 86% for the T-Spot.TB (95% CI, 0.81-0.90). The pooled rate of indeterminate results was low, 2.1% (95% CI, 0.02-0.023) for the QFT-IT and 3.8% (95% CI, 0.035-0.042) for the T-Spot.TB, increasing to 4.4% (95% CI, 0.039-0.05) and 6.1% (95% CI, 0.052-0.071), respectively, among immunosuppressed hosts. The newest commercial IGRAs are superior, in comparison with the TST, for detecting confirmed active TB disease, especially when performed in developed countries.