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

Tuberculosis in United States-Bound Follow-to-Join Asylees, 2014-2019

Persons may seek asylum in the United States or at a U.S. port of entry. Principal asylees are those who are granted asylum status. Their spouse and unmarried children under 21 years of age may be granted asylum if accompanying, or following to join, the principal asylees. U.S.-bound follow-to-join asylees must undergo an overseas medical examination that includes tuberculosis (TB) screening. Culture-based overseas TB screening in U.S.-bound follow-to-join asylees has not been evaluated. We evaluated data from overseas TB screening in 19,088 arrivals of follow-to-join asylees during 2014-2019 and assessed data from their postarrival evaluation, which is recommended for those at risk for TB. Of 19,088 arrivals of follow-to-join asylees, 29 (152 cases/100,000 persons) met criteria for class B0 TB (recent completion of TB treatment overseas) and 340 (1,781 cases/100,000 persons) met criteria for class B1 pulmonary TB (chest radiograph/clinical symptoms suggestive of TB but negative sputum cultures overseas). Of 6,847 persons aged 2 to 14 years from countries with a WHO-estimated TB incidence of ≥20 cases/100,000 population/year, 408 (6.0%) were classified as class B2 latent TB infection (LTBI). Postarrival evaluations were completed in 44.8%, 51.5%, and 40.4% of persons with class B0 TB, class B1 TB, and class B2 LTBI, respectively. In conclusion, culture-based overseas TB screening in U.S.-bound follow-to-join asylees is effective in identifying those with TB (class B0 TB) or those at risk for TB (class B1 TB and class B2 LTBI). Completion of postarrival evaluation for newly arrived follow-to-join asylees was less frequent than that reported for immigrants and refugees.

Overcoming denominator problems in refugee settings with fragmented electronic records for health and immigration data: a prediction-based approach

BACKGROUND

Epidemiological studies in refugee settings are often challenged by the denominator problem, i.e. lack of population at risk data. We develop an empirical approach to address this problem by assessing relationships between occupancy data in refugee centres, number of refugee patients in walk-in clinics, and diseases of the digestive system.

METHODS

Individual-level patient data from a primary care surveillance system (PriCarenet) was matched with occupancy data retrieved from immigration authorities. The three relationships were analysed using regression models, considering age, sex, and type of centre. Then predictions for the respective data category not available in each of the relationships were made. Twenty-one German on-site health care facilities in state-level registration and reception centres participated in the study, covering the time period from November 2017 to July 2021.

RESULTS

445 observations ("centre-months") for patient data from electronic health records (EHR, 230 mean walk-in clinics visiting refugee patients per month and centre; standard deviation sd: 202) of a total of 47.617 refugee patients were available, 215 for occupancy data (OCC, mean occupancy of 348 residents, sd: 287), 147 for both (matched), leaving 270 observations without occupancy (EHR-unmatched) and 40 without patient data (OCC-unmatched). The incidence of diseases of the digestive system, using patients as denominators in the different sub-data sets were 9.2% (sd: 5.9) in EHR, 8.8% (sd: 5.1) when matched, 9.6% (sd: 6.4) in EHR- and 12% (sd 2.9) in OCC-unmatched. Using the available or predicted occupancy as denominator yielded average incidence estimates (per centre and month) of 4.7% (sd: 3.2) in matched data, 4.8% (sd: 3.3) in EHR- and 7.4% (sd: 2.7) in OCC-unmatched.

CONCLUSIONS

By modelling the ratio between patient and occupancy numbers in refugee centres depending on sex and age, as well as on the total number of patients or occupancy, the denominator problem in health monitoring systems could be mitigated. The approach helped to estimate the missing component of the denominator, and to compare disease frequency across time and refugee centres more accurately using an empirically grounded prediction of disease frequency based on demographic and centre typology. This avoided over-estimation of disease frequency as opposed to the use of patients as denominators.

Tuberculosis incidence in foreign-born people residing in European countries in 2020

BackgroundEuropean-specific policies for tuberculosis (TB) elimination require identification of key populations that benefit from TB screening.AimWe aimed to identify groups of foreign-born individuals residing in European countries that benefit most from targeted TB prevention screening.MethodsThe Tuberculosis Network European Trials group collected, by cross-sectional survey, numbers of foreign-born TB patients residing in European Union (EU) countries, Iceland, Norway, Switzerland and the United Kingdom (UK) in 2020 from the 10 highest ranked countries of origin in terms of TB cases in each country of residence. Tuberculosis incidence rates (IRs) in countries of residence were compared with countries of origin.ResultsData on 9,116 foreign-born TB patients in 30 countries of residence were collected. Main countries of origin were Eritrea, India, Pakistan, Morocco, Romania and Somalia. Tuberculosis IRs were highest in patients of Eritrean and Somali origin in Greece and Malta (both > 1,000/100,000) and lowest among Ukrainian patients in Poland (3.6/100,000). They were mainly lower in countries of residence than countries of origin. However, IRs among Eritreans and Somalis in Greece and Malta were five times higher than in Eritrea and Somalia. Similarly, IRs among Eritreans in Germany, the Netherlands and the UK were four times higher than in Eritrea.ConclusionsCountry of origin TB IR is an insufficient indicator when targeting foreign-born populations for active case finding or TB prevention policies in the countries covered here. Elimination strategies should be informed by regularly collected country-specific data to address rapidly changing epidemiology and associated risks.

Active and latent TB screening in recently arrived persons from Afghanistan: feasibility and lessons learned

We describe an active and latent tuberculosis (TB) screening programme undertaken in Manchester, UK in response to the arrival of a cohort of refugees from Afghanistan. In total, 217 adults and 347 children were offered screening, which involved a symptom questionnaire, Mantoux test or interferon gamma release assay, blood-borne virus screening and a chest X-ray in participants over the age of 11. We found a latent TB infection (LTBI) rate of 15% in adults and 1.5% in children, which is lower than global LTBI estimates. One case of active TB was detected. Screening was undertaken in the hotels where participants were temporarily housed, leading to high participant engagement levels. Attendance rates were almost doubled compared with a previous hospital-based screening programme. Hotel-based screening for TB presented several challenges, including transfer of information and results to secondary care. Understanding these challenges and learning from the programme has helped us refine our screening protocol to optimise migrant TB screening in Manchester in the future.

'German Health Update Fokus (GEDA Fokus)': Study Protocol of a Multilingual Mixed-mode Interview Survey among Residents with Croatian, Italian, Polish, Syrian or Turkish Citizenship in Germany

BACKGROUND

Germany has a long history of migration. In 2020, more than every fourth person had a statistically defined, so-called 'migration background' in Germany, meaning that the person or at least one of their parents was born with a citizenship other than German. People with a history of migration are not represented proportionately to the population within public health monitoring at the Robert Koch Institute (RKI), thus impeding differentiated analyses on migration and health. In order to develop strategies to improve the inclusion of people with a history of migration in health surveys, we conducted a feasibility study in 2018. Lessons learned were implemented in the health interview survey GEDA Fokus which was conducted among people with selected citizenships representing the major migrant groups in Germany.

OBJECTIVE

The main objective of GEDA Fokus was to collect comprehensive data on the health status and social, migration-related, and structural factors among people with selected citizenships in order to enable differentiated explanations on the associations between migration-related aspects and their impact on migrant health.

METHODS

GEDA Fokus was an interview survey among people with Croatian, Italian, Polish, Syrian, or Turkish citizenship living in Germany aged 18 - 79 years, with a targeted sample size of 1,200 participants per group. The gross sample of 33,436 people was drawn out of the residents' registration offices of 99 German municipalities based on citizenship. Sequentially, multiple modes of administration were offered. The questionnaire was available for self-administration (online and paper-based); in bigger municipalities, personal or phone interviews were possible later on. Study documents and the questionnaire were bilingual, in German and the respective translation language depending on the citizenship. Data collection took place from November 2021 until May 2022.

RESULTS

Overall, 6,038 respondents participated in the survey, 49.4% were female. The median age was 39 years, and the median duration of residence in Germany was 10 years, with 19.7% of the sample being born in Germany. The overall response rate was 18.4% (AAPOR response rate 1) and was 6.8% higher in the municipalities where personal interviews were offered (19.3% vs. 12.5%). Overall, 78.2% administered the questionnaire on their own, while 21.9% took part in a personal interview. A total of 41.9% answered the questionnaire in German language only, 16.7% exclusively used the translation, and 41.4% used both languages in the bilingual version of the questionnaire.

CONCLUSIONS

Offering different modes of administration, as well as multiple study languages, enabled us to recruit a heterogeneous sample of people with a history of migration. The data collected will allow differentiated analyses of the role and interplay of migration-related and social determinants of health and their impact on the health status of people with selected citizenships.

CLINICALTRIAL

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.

Health status of recently arrived asylum seekers in their host country: results of a cross-sectional observational study

Background

The World Health Organization (WHO) considers that the heterogeneity of concepts and definitions of migrants is an obstacle to obtaining evidence to inform public health policies. There is no recent data on the health status of only asylum seekers who have recently arrived in their Western host country. The purpose of this study was to determine the health status of asylum seekers and search for explanatory factors for this health status.

Methods

This cross-sectional observational study screened the mental and somatic health of adult asylum seekers who had arrived in France within the past 21 days and went to the Marseille single center between March 1 and August 31, 2021. In order to study the explanatory factors of the asylum seekers' health status, a multivariate analysis was performed using a logistic regression model to predict the health status. Factors taken into account were those significantly associated with outcome (level < 0.05) in univariate analysis.

Results

In total, 419 asylum seekers were included and 96% CI95%[93;97.3] had at least one health disorder. Concerning mental health, 89% CI95% [85.1;91.4] had a mental disorder and in terms of somatic health exclusively, 66% CI95% [61.4;70.6] had at least one somatic disorder. Women were more likely to have a somatic disease OR = 1.80 [1.07; 3.05]. We found a statistically significant association between the presence of at least one disorder and sleeping in a public space OR = 3.4 [1.02;11.28] p = 0.046. This association is also found for mental disorders OR = 2.36 [1.16;4.84], p = 0.018.

Conclusions

Due to the high prevalence of health disorders our study found, asylum seekers are a population with many care needs when they arrive in their host country. The main factors linked to a poor health status seem to be related to a person’s sex, geographical origin and sleeping in a public space.

Tuberculosis screening among newly arrived asylum seekers in Denmark

BACKGROUND

Tuberculosis (TB) screening programmes among asylum seekers tend to focus on chest radiography (CXR) for early diagnosis, whereas knowledge on sputum examination is limited. We evaluated active TB screening using CXR and sputum culture among asylum seekers arriving in Denmark. In addition, we assessed the coverage of a voluntary health assessment.

METHODS

Between 1 February 2017 and 31 March 2019, all newly arrived asylum seekers in Denmark ≥ 18 years from TB high-incidence countries or risk groups, who attended a voluntary general health assessment, were offered active TB screening with CXR and spot sputum examination. Sputum samples were examined by culture and smear microscopy.

RESULTS

Coverage of the general health assessment was 65.1%. Among 1,154 referred for active TB screening, 923 (80.0%) attended. Of these, 854 were screened by CXR and one case of active TB was identified equivalent to a yield of 0.12%. Sputum samples were collected from 758 and one M. tuberculosis culture-positive TB case (also identified by CXR) was identified, equivalent to a yield of 0.13%. No cases were found by sputum culture screening only. In addition, screening found three cases of malignant disease.

CONCLUSION

We suggest that TB screening should focus on asylum seekers from TB high-incidence countries. Furthermore, early health assessments should be of high priority to ensure migrant health.

The cascade of care in tuberculosis infection screening and management in newly arrived refugees in Aarhus, Denmark

BACKGROUND

Screening for tuberculosis (TB) disease and infection is often a part of health screening programs offered to refugees, but the yield of screening varies and losses along the steps from screening to treatment completion was reported.

METHODS

A retrospective cohort study was performed investigating a newly arrived refugee population offered a systematic refugee health assessment in Aarhus, Denmark. Data was collected on screening, referral, diagnosis and treatment for TB disease and infection.

RESULTS

Among both adults and children IGRA positivity was associated with origin in a high TB incidence country and increasing age. The number needed to screen (NNS) to find one case of TB infection was 7 among adult refugees and 19 among children, while NNS for TB disease was 266 and 164 respectively. The proportion of the eligible population with a valid result was 78.1% for adults and 71.3% for children, while 43.1% and 50% of adults and children with presumed TB infection completed preventive treatment.

DISCUSSION

Screening for TB disease and infection among refugees in Aarhus had a high yield in terms of diagnosis, however significant losses were seen during screening, follow-up and preventive treatment completion.

Subclinical tuberculosis in children: diagnostic strategies for identification reported in a 6-year national prospective surveillance study

BACKGROUND

Subclinical tuberculosis (TB) is well recognized and defined as a disease state with absent or non-recognized symptoms. The study identifies factors associated with subclinical TB and diagnostic strategies in a low-burden, high-resource country.

METHODS

Data was collected between December 2013 to November 2019 through the Swiss Pediatric Surveillance Unit (SPSU). Children with culture/molecular confirmed TB, or who were treated with ≥3 anti-mycobacterial drugs, were included.

RESULTS

A total of 138 (80%) children with TB disease were included in the final analysis, of which 43 (31%) were subclinical. The median age of children with subclinical compared to symptomatic TB was 3.7(IQR 2.2 to 7) and 9.7(IQR 2.7 to 14.3) years, respectively (p=0.003). The cause of investigation for TB was recorded in 31/43 (72.1%) of children with subclinical TB, and included contact exposure in 25 (80.6%). In children with subclinical TB, diagnosis was made by a combination of the following abnormal/confirming results: culture/molecular + immunodiagnostic + chest radiography in 12 (27.9%), immunodiagnostic + chest radiography in 19 (44.2%), culture/molecular + chest radiography in 2 (4.7%), culture + immunodiagnostic in 1 (2.3%), chest radiography only in 8 (18.6%) and immunodiagnostic only in 1 (2.3%) case.

CONCLUSION

A notable proportion of children with TB had subclinical disease. This highlights the importance of non-symptom-based TB case finding in exposed children and refugees from high-TB-prevalence settings. TB screening in these asymptomatic children should therefore include a combination of immunodiagnostic testing and imaging followed by culture and molecular testing.

Cost-effectiveness of targeted screening for active pulmonary tuberculosis among asylum-seekers: A modelling study with screening data from a German federal state (2002-2015)

Screening asylum-seekers for active pulmonary tuberculosis is common practice among many European countries with low incidence of tuberculosis. The reported yields vary substantially, partly due to the heterogeneous and dynamic nature of asylum-seeking populations. Rather than screening all new arrivals (indiscriminate screening), a few countries apply targeted screening based on incidence of tuberculosis in asylum-seekers' country of origin. However, evaluations of its cost-effectiveness have been scarce. The aim of this modelling study was to assess whether the introduction of a screening threshold based on the tuberculosis incidence in the country of origin is sensible from an economic perspective. To this end, we compare the current, indiscriminate screening policy for pulmonary tuberculosis in Germany with a hypothetical targeted screening programme using several potential screening thresholds based on WHO-reported incidence of tuberculosis in countries of origin. Screening data is taken from a large German federal state over 14 years (2002-2015). Incremental cost-effectiveness is measured as cost per case found and cost per case prevented. Our analysis shows that incremental cost-effectiveness ratios (ICERs) of screening asylum-seekers from countries with an incidence of 50 to 250/100,000 range between 15,000€ and 17,000€ per additional case found when compared to lower thresholds. The ICER for screening asylum-seekers from countries with an incidence <50/100,000 is 112,000€ per additional case found. Costs per case prevented show a similar increase in costs. The high cost per case found and per case prevented at the <50/100,000 threshold scenario suggests this threshold to be a sensible cut-off for targeted screening. Acknowledging that no screening measure can find all cases of tuberculosis, and that reactivation of latent infections makes up a large proportion of foreign-born cases, targeting asylum-seekers from countries with an incidence above 50/100,000 is likely to be a more reasonable screening measure for the prevention and control of tuberculosis than indiscriminate screening measures.

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.