Pre-entry, post-entry, or no tuberculosis screening?

Mandatory, voluntary, repetitive, or one-off post-migration follow-up for tuberculosis prevention and control: A systematic review

BACKGROUND

Post-migration follow-up of migrants identified to be at-risk of developing tuberculosis during the initial screening is effective, but programmes vary across countries. We aimed to review main strategies applied to design follow-up programmes and analyse the effect of key programme characteristics on reported coverage (i.e., proportion of migrants screened among those eligible for screening) or yields (i.e., proportion of active tuberculosis among those identified as eligible for follow-up screening).

METHODS AND FINDINGS

We performed a systematic review and meta-analysis of studies reporting yields of follow-up screening programmes. Studies were included if they reported the rate of tuberculosis disease detected in international migrants through active case finding strategies and applied a post-migration follow-up (defined as one or more additional rounds of screening after finalising the initial round). For this, we retrieved all studies identified by Chan and colleagues for their systematic review (in their search until January 12, 2017) and included those reporting from active follow-up programmes. We then updated the search (from January 12, 2017 to September 30, 2022) using Medline and Embase via Ovid. Data were extracted on reported coverage, yields, and key programme characteristics, including eligible population, mode of screening, time intervals for screening, programme providers, and legal frameworks. Differences in follow-up programmes were tabulated and synthesised narratively. Meta-analyses in random effect models and exploratory analysis of subgroups showed high heterogeneity (I2 statistic > 95.0%). We hence refrained from pooling, and estimated yields and coverage with corresponding 95% confidence intervals (CIs), stratified by country, legal character (mandatory versus voluntary screening), and follow-up scheme (one-off versus repetitive screening) using forest plots for comparison and synthesis. Of 1,170 articles, 24 reports on screening programmes from 7 countries were included, with considerable variation in eligible populations, time intervals of screening, and diagnostic protocols. Coverage varied, but was higher than 60% in 15 studies, and tended to be lower in voluntary compared to compulsory programmes, and higher in studies from the United States of America, Israel, and Australia. Yield varied within and between countries and ranged between 53.05 (31.94 to 82.84) in a Dutch study and 5,927.05 (4,248.29 to 8,013.71) in a study from the United States. Of 15 estimates with narrow 95% CIs for yields, 12 were below 1,500 cases per 100,000 eligible migrants. Estimates of yields in one-off follow-up programmes tended to be higher and were surrounded by less uncertainty, compared to those in repetitive follow-up programmes. Yields in voluntary and mandatory programmes were comparable in magnitude and uncertainty. The study is limited by the heterogeneity in the design of the identified screening programmes as effectiveness, coverage and yields also depend on factors often underreported or not known, such as baseline incidence in the respective population, reactivation rate, educative and administrative processes, and consequences of not complying with obligatory measures.

CONCLUSION

Programme characteristics of post-migration follow-up screening for prevention and control of tuberculosis as well as coverage and yield vary considerably. Voluntary programmes appear to have similar yields compared with mandatory programmes and repetitive screening apparently did not lead to higher yields compared with one-off screening. Screening strategies should consider marginal costs for each additional round of screening.

Tuberculosis in international immigrants: profile and vulnerability of cases residing in the municipality of São Paulo, Brazil

Objective

To analyze the profile of immigrants with tuberculosis (TB) and to identify the associated vulnerability characteristics.

Methods

A cross-sectional study which used TB-WEB data from cases residing in São Paulo in 2016 (203 immigrants and 6,069 non-immigrants). The variables were analyzed using prevalence ratio and confidence intervals.

Results

Among the immigrant cases, 67% were Bolivians. When compared to non-immigrants, immigrants were younger and frequently indigenous or presenting yellow ethnicity. They were also associated with a higher education level. We observed less immigrants having extrapulmonary TB and comorbidities, such as HIV/AIDS, diabetes mellitus, or drug use. Compared to cured cases, immigrants were not associated with treatment default and death, but they were associated with transfer to another state/country.

Conclusions

Younger individuals and higher education levels were identified among immigrants, as well as a lower occurrence of comorbidities and drug use. It is believed that these results have led immigrants to more favorable outcomes of TB treatment.

Asylum seekers' perspectives on vaccination and screening policies after their arrival in Greece and The Netherlands

Introduction

Europe has been dealing with an increasing number of refugees during the past 5 years. The timing of screening and vaccination of refugees is debated by many professionals, however refugees’ perspectives on health issues are infrequently taken into account. In this study, we aimed to investigate asylum seekers’ perspectives on infectious diseases screening and vaccination policies.

Materials and methods

Interviews were conducted in Greece and the Netherlands. Asylum seekers and recently arrived refugees were approached and informed with the help of interpreters; consent forms were acquired. The survey focused on demographic data, vaccination status, screening policies and prevention of infectious diseases.

Results

A total of 61 (43 male, 70.5%) refugees (30 Afghanis, 16 Syrian, 7 Erithrean) were interviewed. Mean age was 35.2 years (SD 13.5) and 50% had received primary or secondary education, while 24.6% received none. Median time after arrival in Greece and the Netherlands was 24 months (IQR 8.5–28). 44 out of 61 (72.1) participants were willing to be vaccinated after arrival in Europe, 26 preferred vaccination and screening to be performed at the point of entry. The need for screening and vaccination was perceived higher amongst participants in Greece (100% vs 43.3%) due to living conditions leading to increased risk of outbreaks.

Conclusion

Participants were willing to communicate their perspectives and concerns. Screening and vaccination programs could be more effective when implemented shortly after arrival and by involving asylum seekers and refugees when developing screening and vaccination interventions.

Defining a migrant-inclusive tuberculosis research agenda to end TB

BACKGROUND

Pillar 3 of the End TB Strategy calls for the promotion of research and innovation at the country level to facilitate improved implementation of existing and novel interventions to end tuberculosis (TB). In an era of increasing cross-border migration, there is a specific need to integrate migration-related issues into national TB research agendas. The objective of the present review is to provide a conceptual framework to guide countries in the development and operationalization of a migrant-inclusive TB research agenda.

METHODS

We conducted a literature review, complemented by expert opinion and the previous articles in this State of the Art series, to identify important themes central to migration-related TB. We categorized these themes into a framework for a migration-inclusive global TB research agenda across a comprehensive spectrum of research. We developed this conceptual framework taking into account: 1) the biomedical, social and structural determinants of TB; 2) the epidemiologic impact of the migration pathway; and 3) the feasibility of various types of research based on a country's capacity.

DISCUSSION

The conceptual framework presented here is based on the key principle that migrants are not inherently different from other populations in terms of susceptibility to known TB determinants, but that they often have exacerbated or additional risks related to their country of origin and the migration process, which must be accounted for in developing comprehensive TB prevention and care strategies. A migrant-inclusive research agenda should systematically consider this wider context to have the highest impact.

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.

Infectious disease screening in asylum seekers: range, coverage and economic evaluation in Germany, 2015

Screening asylum seekers for infectious diseases is widely performed, but economic evaluations of such are scarce. We performed a policy analysis and economic evaluation of such screening in Germany, and analysed the effect of screening policies on cost differences between federal states. Of the 16 states, screening was compulsory for tuberculosis (TB) in asylum seekers ≥ 16 years of age in all states as well as in children < 16 years of age and pregnant women in six states, hepatitis B and enteropathogens in three, syphilis in two and human immunodeficiency virus (HIV) in one state. Of 441,899 asylum seekers, 88.0% were screened for TB, 22.9% for enteropathogens, 16.9% for hepatitis B, 13.1% for syphilis and 11.3% for HIV. The total costs for compulsory screening in 2015 were 10.3 million euros (EUR). Costs per case were highest for infections with Shigella spp. (80,200 EUR), Salmonella spp. (8,000 EUR), TB in those ≥ 16 years of age (5,300 EUR) and syphilis (1,150 EUR). States with extended screening had per capita costs 2.84 times those of states that exclusively screened for TB in asylum seekers ≥ 16 years of age (p < 0.0001, 95% confidence interval (CI): 1.96–4.10). Screening practices in Germany entailed high costs; evidence-based approaches to infectious disease screening are needed.

Delayed diagnosis of severe tuberculous spondylodiscitis in an asylum seeker; patient or doctors delay?

The still increasing global migration affects the epidemiology of tuberculosis (TB) in European countries. We present the case of an asylum seeker from a TB high-endemic country, who presented with severe TB spondylodiscitis and need for emergency surgery. The patient had a history of recurrent sterile axillary and perianal abscesses for years, but TB was never properly ruled out. The patient underwent surgery, responded well to antibiotics and regained the ability to walk. After 6 month of treatment the patient was lost to follow-up. In light of the increasing migration from TB high-endemic countries to low-endemic countries, this case illustrates the paramount importance of minding TB as a differential diagnosis.

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.

Pott's disease: a major issue for an unaccompanied refugee minor

The incidence of TB in children in Germany has been on a rise since 2008, especially among foreign-born individuals. With rapidly increasing numbers of refugees from the numerous areas of conflict, this increase in incidence is not expected to halt, neither in Germany nor in Europe in general. We report a case of insufficient tracking in a 16-year-old unaccompanied refugee minor from Somalia who had a positive interferon γ release assay on arrival in Germany. No actions were undertaken, until 6 months later, an X-ray showed prominent hilar enlargement. Nine  months later, the patient presented to our hospital with abdominal pain, vomiting and B symptoms. Workup revealed a paravertebral abscess due to Pott's disease, a skeletal manifestation of Mycobacterium tuberculosis disease. The patient made a full recovery after a combination therapy for a total of 9 months.

A Step toward Tuberculosis Elimination in a Low-Incidence Country: Successful Diagnosis and Treatment of Latent Tuberculosis Infection in a Refugee Clinic

Objectives. Approximately 65 percent of tuberculosis (TB) cases in Canada each year occur from reactivation in foreign-born individuals. Refugees are at high risk after immigration. Routine screening of this population for latent TB infection (LTBI) is generally considered infeasible. We evaluated the outcome of LTBI screening and treatment amongst refugees. Methods. Government-sponsored refugees in Edmonton are seen at the New Canadians' Clinic and screened for TB and LTBI. We reviewed records of patients between 2009 and 2011. Completeness of initial assessment, diagnosis of latent infection, and completion of LTBI treatment were evaluated. Treatment for LTBI was offered when patients had a positive Tuberculin Skin Test (TST) and risk factors for progression to TB. An Interferon-Gamma Release Assay (IGRA) was performed on all other TST positives; treatment is only offered if it was positive. Results. 949 refugees were evaluated. 746 TSTs were read, with 265 positive individuals. IGRA testing was performed in 203 TST positive individuals without other TB risk factors; 110 were positive. LTBI treatment was offered to 147 of 151 eligible patients, 141 accepted, and 103 completed a treatment course. Conclusion. We observed high proportions of patient retention, completion of investigations, and treatment. This care model promises to be a component of effective TB prevention in this high-risk population.

Screening for Infectious Diseases among Newly Arrived Migrants: Experiences and Practices in Non-EU Countries of the Mediterranean Basin and Black Sea

Changing migration dynamics in the Mediterranean Sea and differences in infectious diseases (ID) burden between the countries of origin have raised questions whether public health actions are needed to avoid the transmission of ID. Screening newly arrived migrants for ID is one health monitoring option, offering opportunities for prevention, early detection and treatment. The authors conducted a survey among country experts in non-European Union countries of the Mediterranean and Black Sea, in order to explore current ID screening practices and policies for newly arrived migrants. The association between the existence of guidelines and the proportion of refugees in the population was also estimated. Eighteen country experts responded (90%) out of the 20 invited. Eleven countries (61%) implemented screening programmes and six (38%) had national guidelines. Screening was performed most often for tuberculosis at the holding level. A higher proportion of refugees in the population was associated with the existence of guidelines for screening (p = 0.05). Fourteen experts (88%) considered screening among migrants useful. The results show that screening for ID in newly arrived migrants is relevant for non-EU countries of the Mediterranean and Black Sea. Common guidelines could be promoted focusing on both individual and public health benefits of screening programmes.