Defining a migrant-inclusive tuberculosis research agenda to end TB

Strengthening Tuberculosis Control Among Migrant Workers

Tuberculosis (TB) is a serious infectious disease accounting for a significant number of deaths due to the infectious nature of the disease on the global platform. Migrant workers need special attention as these population groups live in substandard and crowded environmental conditions with poor ventilation, which play a crucial role in augmenting the risk of acquisition of infection. The global vision to ensure the delivery of effective TB control-related services for migrant workers has been influenced by a wide range of barriers. This issue is further complicated by the limited knowledge of migrant workers about tuberculosis, their rights, the kind of services available in healthcare facilities, and the ways to prevent the acquisition and transmission of infectious disease. By acknowledging the role of predisposing factors and the potential barriers that impact accessing timely healthcare services, it can be seen that the need of the hour is to plan and implement a comprehensive package of services for the benefit of migrant workers.

Migration and medical screening for tuberculosis

Vulnerable populations, such as migrants and refugees, have an increased risk of tuberculosis disease, especially in the first years after arrival in the host country. The presence of migrants and refugees in Brazil exponentially grew over the period between 2011 and 2020, and approximately 1.3 million migrants from the Global South were estimated to be residing in Brazil, most of whom from Venezuela and Haiti. Tuberculosis control programs for migrants can be divided into pre- and post-migration screening strategies. Pre-migration screening aims to identify cases of tuberculosis infection (TBI) and can be carried out in the country of origin (pre-entry) or in the destination country (at entry). Pre-migration screening can also detect migrants at an increased risk of developing tuberculosis in the future. High-risk migrants are then followed up in post-migration screening. In Brazil, migrants are considered a priority group for the active search for tuberculosis cases. However, there is no recommendation or plan regarding screening for TBI in migrants and refugees. Ensuring prevention, diagnosis, and treatment for TBI and tuberculosis disease in migrant populations is an important aspect of tuberculosis control and elimination. In this review article, we address epidemiological aspects and access to health care for migrants in Brazil. In addition, the migration medical screening for tuberculosis was reviewed.

Fragmentation of Healthcare Services as a Possible Determinant of the Low Completion for the Tuberculosis Cascade of Prevention among Asylum Seekers: Results from a Prospective Study with Historical Comparison

Background: Effective screening for tuberculosis infection (TBI) among asylum seekers (AS) is crucial for tuberculosis (TB) elimination in low incidence countries. Methods: We assessed the proportion of completion of the screening for TBI among asylum seekers with a centralized delivery method compared to the decentralized model previously adopted in the study area (historical control). In the historical model (January 2017 to May 2018) screening of AS was performed at the arrival offering TBI testing (TST followed by IGRA among those positive), radiological investigation, treatment initiation and hospital referral, if needed, at three sites: migrant health clinic, pneumology clinic and infectious diseases department for active disease (decentralized model). In the study model (June 2018, centralized) all steps of screening were performed at a single site, at a minimum of 6 months after arrival. Multivariable Poisson regression analysis, with robust variance, was used to assess variables associated with the completion of screening for infection. Multivariable logistic regression was used to identify factors associated with the diagnosis of TB infection. Results: The intervention approach was offered to 144 AS with an overall 98.6% proportion of completion (98.7% for those with a positive TST). In the historical screening model, 1192 AS were candidates for screening, which was completed by 74.5% of those who started it (44.7% for those resulted TST positive). Major losses (55%) were detected in the TST/CXR-IGRA sequential step, followed by the execution of TST test (25%). The ratio of screening completion was significantly higher in the intervention period (aIRR 1.78, 95% CI 1.68–1.88) and for AS coming from high incidence TB countries (aIRR 1.14, 95% CI 1.04–1.25). Screening after 6 months from arrival and age were associated with TB infection (2.09, 95% CI 1.36–3.2 and 1.14, 95% CI 1.01–1.29). Conclusions: Screening for TBI can be improved by a centralized approach. Higher prevalence of TBI 6 months after arrival could reflect recent (either during travel or in Italy) acquisition of the infection.

Screening for Tuberculosis in Migrants: A Survey by the Global Tuberculosis Network

Tuberculosis (TB) does not respect borders, and migration confounds global TB control and elimination. Systematic screening of immigrants from TB high burden settings and-to a lesser degree TB infection (TBI)-is recommended in most countries with a low incidence of TB. The aim of the study was to evaluate the views of a diverse group of international health professionals on TB management among migrants. Participants expressed their level of agreement using a six-point Likert scale with different statements in an online survey available in English, French, Mandarin, Spanish, Portuguese and Russian. The survey consisted of eight sections, covering TB and TBI screening and treatment in migrants. A total of 1055 respondents from 80 countries and territories participated between November 2019 and April 2020. The largest professional groups were pulmonologists (16.8%), other clinicians (30.4%), and nurses (11.8%). Participants generally supported infection control and TB surveillance established practices (administrative interventions, personal protection, etc.), while they disagreed on how to diagnose and manage both TB and TBI, particularly on which TBI regimens to use and when patients should be hospitalised. The results of this first knowledge, attitude and practice study on TB screening and treatment in migrants will inform public health policy and educational resources.

Effects of migration on tuberculosis epidemiological indicators in low and medium tuberculosis incidence countries: A systematic review

BACKGROUND

Tuberculosis (TB) remains one of the top ten causes of death each year globally. While the risk of migrant TB is linked to the TB incidence in their country of origin, the migration process can increase the TB risk.

OBJECTIVE

We aimed to synthesis the evidence on key differences in the epidemiological profile of TB between migrants from high TB incidence birth countries and non-migrants resident in low to medium incidence TB countries.

METHODS

We conducted a systematic review where the population was all active TB cases in countries with low to medium TB incidence (<40/100,000 population), the exposure was migration to a low or medium TB incidence country and the comparator was non-migrant TB cases in low or medium incidence countries. Overall proportions were compared between migrants and non-migrants, using Fisher's exact test. Meta-analysis of proportions was carried out for the primary outcome (active TB) while meta-analyses of odds ratios (ORs) were performed using a random effects model for secondary outcomes; sputum-smear positivity, any first line drug resistance, multi-drug resistance (MDR), clustered cases, HIV coinfections and successful treatment. Heterogeneity was evaluated and sources were investigated using subgroup and sensitivity analysis.

RESULTS

Significant differences were found in the overall proportions of high TB incidence migrants and non-migrants for MDR cases, clustered cases, HIV coinfections and successful treatment, as well as a significant difference in the OR among MDR cases (3.91).

CONCLUSION

This review has demonstrated significant differences in key epidemiological indicators between high TB incidence migrants and non-migrants, indicating policy implications.

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).

Evaluation of the latent tuberculosis screening and treatment strategy for asylum seekers in Stockholm, Sweden 2015-2018: a record linkage study of the care cascade

INTRODUCTION

About 90% of active tuberculosis (TB) cases in Sweden are foreign born and are mainly due to latent TB infection (LTBI) reactivation. The aim of this study was to assess the current migrant LTBI screening programme with regards to test results and completion of the care cascade.

METHOD

A retrospective cohort of all 14173 individuals attending a health examination was established for the Stockholm Region 2015-2018 through record-linkage of data extracted from the Swedish Migration Authority and medical records. Screening results, referrals to specialist care and treatment initiation were ascertained through automated data extraction for the entire cohort. Detailed cascade steps, including treatment completion, were analysed through manual data extraction for a subsample of all persons referred to specialist care in the period 2016-2017.

RESULTS

Of 5470 patients screened with an interferon-gamma release assay (IGRA), 1364 (25%) were positive, of whom 358 (26%) initiated LTBI treatment. An increased trend in IGRA-positivity was seen for increased age and TB-incidence in country of origin. Among the IGRA positive patients, 604 (44%) were referred to specialist care. Lower age was the main referral predictor. In the subsample of 443 patients referred to specialist care in 2016-2017, 386 (87%) were invited, of whom 366 (95%) attended. Of 251 patients (69%) recommended for LTBI treatment, 244 (97%) started such treatment and of those 221 (91%) completed it.

CONCLUSION

The low attrition in patient-dependent cascade steps shows that the voluntary approach works well. Low LTBI treatment attainment is due to the current conservative local treatment policy, which means the vast majority are IGRA-tested without an intention to treat for LTBI.

Increasing Drug Resistance Among Persons With Tuberculosis in Massachusetts, 2009-2018

We examined Massachusetts tuberculosis surveillance data from to 2009 to 2018. Of 1533 culture-confirmed cases, 190 (12.4%) demonstrated resistance to isoniazid including 32 (2.1%) with rifampin resistance. In multivariable analysis, isoniazid resistance increased significantly over time (per-year odds ratio = 1.07, 95% confidence interval = 1.01-1.13, P = .018) and was associated with younger age, foreign birth, and prior tuberculosis treatment.

Active and latent tuberculosis in refugees and asylum seekers: a systematic review and meta-analysis

BACKGROUND

In 2018, there were 70.8 million refugees, asylum seekers and persons displaced by wars and conflicts worldwide. Many of these individuals face a high risk for tuberculosis in their country of origin, which may be accentuated by adverse conditions endured during their journey. We summarised the prevalence of active and latent tuberculosis infection in refugees and asylum seekers through a systematic literature review and meta-analyses by country of origin and host continent.

METHODS

Articles published in Medline, EMBASE, Web of Science and LILACS from January 2000 to August 2017 were searched for, without language restriction. Two independent authors performed the study selection, data extraction and quality assessment. Random effect models were used to estimate average measures of active and latent tuberculosis prevalence. Sub-group meta-analyses were performed according to country of origin and host continent.

RESULTS

Sixty-seven out of 767 identified articles were included, of which 16 entered the meta-analyses. Average prevalence of active and latent tuberculosis was 1331 per 100 thousand inhabitants [95% confidence interval (CI) = 542-2384] and 37% (95% CI = 23-52%), respectively, both with high level of heterogeneity (variation in estimative attributable to heterogeneity [I2] = 98.2 and 99.8%). Prevalence varied more according to countries of origin than host continent. Ninety-one per cent of studies reported routine screening of recently arrived immigrants in the host country; two-thirds confirmed tuberculosis bacteriologically. Many studies failed to provide relevant information.

CONCLUSION

Tuberculosis is a major health problem among refugees and asylum seekers and should be given special attention in any host continent. To protect this vulnerable population, ensuring access to healthcare for early detection for prevention and treatment of the disease is essential.

Tools to implement the World Health Organization End TB Strategy: Addressing common challenges in high and low endemic countries

AIM

The purpose of this viewpoint is to summarize the advantages and constraints of the tools and strategies available for reducing the annual incidence of tuberculosis (TB) by implementing the World Health Organization (WHO) End TB Strategy and the linked WHO TB Elimination Framework, with special reference to Oman.

METHODS

The case-study was built based on the presentations and discussions at an international workshop on TB elimination in low incidence countries organized by the Ministry of Health, Oman, which took place from September 5 to September 7, 2019, and supported by the WHO and European Society of Clinical Microbiology and Infectious Diseases (ESCMID).

RESULTS

Existing tools were reviewed, including the screening of migrants for latent TB infection (LTBI) with interferon-gamma release assays, clinical examination for active pulmonary TB (APTB) including chest X-rays, organization of laboratory services, and the existing centres for mandatory health examination of pre-arrival or arriving migrants, including examination for APTB. The need for public-private partnerships to handle the burden of screening arriving migrants for active TB was discussed at length and different models for financing were reviewed.

CONCLUSIONS

In a country with a high proportion of migrants from high endemic countries, screening for LTBI is of high priority. Molecular typing and the development of public-private partnerships are needed.

The association between internal migration and pulmonary tuberculosis in China, 2005-2015: a spatial analysis

BACKGROUND

Internal migration places individuals at high risk of contracting tuberculosis (TB). However, there is a scarcity of national-level spatial analyses regarding the association between TB and internal migration in China. In our research, we aimed to explore the spatial variation in cases of sputum smear-positive pulmonary TB (SS + PTB) in China; and the associations between SS + PTB, internal migration, socioeconomic factors, and demographic factors in the country between 2005 and 2015.

METHODS

Reported cases of SS + PTB were obtained from the national PTB surveillance system database; cases were obtained at the provincial level. Internal migration data were extracted from the national population sampling survey and the census. Spatial autocorrelations were explored using the global Moran's statistic and local indicators of spatial association. The spatial temporal analysis was performed using Kulldorff's scan statistic. Fixed effects regression was used to explore the association between SS + PTB and internal migration.

RESULTS

A total of 4 708 563 SS + PTB cases were reported in China between 2005 and 2015, of which 3 376 011 (71.7%) were male and 1 332 552 (28.3%) were female. There was a trend towards decreasing rates of SS + PTB notifications between 2005 and 2015. The result of global spatial autocorrelation indicated that there were significant spatial correlations between SS + PTB rate and internal migration each year (2005-2015). Spatial clustering of SS + PTB cases was mainly located in central and southern China and overlapped with the clusters of emigration. The proportions of emigrants and immigrants were significantly associated with SS + PTB. Per capita GDP and education level were negatively associated with SS + PTB. The internal migration flow maps indicated that migrants preferred neighboring provinces, with most migrating for work or business.

CONCLUSIONS

This study found a significant spatial autocorrelation between SS + PTB and internal migration. Both emigration and immigration were statistically associated with SS + PTB, and the association with emigration was stronger than that for immigration. Further, we found that SS + PTB clusters overlapped with emigration clusters, and the internal migration flow maps suggested that migrants from SS + PTB clusters may influence the TB epidemic characteristics of neighboring provinces. These findings can help stakeholders to implement effective PTB control strategies for areas at high risk of PTB and those with high rates of internal migrants.

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

Background

The identification and treatment of LTBI is a key component of the WHO’s strategy to eliminate TB. Recent migrants from high TB-incidence countries are recognised to be at risk TB reactivation, and many high-income countries have focused on LTBI screening and treatment programmes for this group. However, migrants are the group least likely to complete the LTBI cascade-of-care. This pragmatic cluster-randomised, parallel group, superiority trial investigates whether a model of care based entirely within a community setting (primary care) will improve treatment completion compared with treatment in specialist TB services (secondary care).

Methods

The CATAPuLT trial (Completion and Acceptability of Treatment Across Primary Care and the community for Latent Tuberculosis) randomised 34 general practices in London, England, to evaluate the efficacy and safety of treatment for LBTI in recent migrants within primary care. GP practices were randomised to either provide management for LTBI entirely within primary care (GPs and community pharmacists) or to refer patients to secondary care. The target recruitment number for individuals is 576. The primary outcome is treatment completion (defined as taking at least 90% of antibiotic doses). The secondary outcomes assess adherence, acceptance of treatment, the incidence of adverse effects including drug-induced liver injury, the rates of active TB, patient satisfaction and cost-effectiveness of LTBI treatment. This protocol adheres to the SPIRIT Checklist.

Discussion

The CATAPuLT trial seeks to provide implementation research evidence for a patient-centred intervention to improve treatment completion for LTBI amongst recent migrants to the UK.

Trial registration

NCT03069807, March 2017, registered retrospectively.

App-based symptoms screening with Xpert MTB/RIF Ultra assay used for active tuberculosis detection in migrants at point of arrivals in Italy: The E-DETECT TB intervention analysis

Background

From 2014 to 2017, the number of migrants who came to Italy via the Mediterranean route has reached an unprecedented level. The majority of refugees and migrants were rescued in the Central Mediterranean and disembarked at ports in the Sicily region. Rapid on-spot active TB screening intervention at the point of arrival will cover most migrants arriving in EU and by detecting TB prevalent cases will limit further transmission of the disease.

Material and methods

Between November 2016 and December 2017 newly arrived migrants at point of arrivals in Sicily, were screened for active Tuberculosis using a smartphone application, followed in symptomatic individuals by fast molecular test, Xpert MTB/RIF Ultra, on collected sputum samples.

Results

In the study period 3787 migrants received a medical evaluation. Eight hundred and ninety-one (23.5%) reported at least one protocol-defined Tuberculosis symptom. Fifteen (2.7%) were positive to at least one microbiological test revealing a post-entry screening prevalence rate of 396 per 100.000 individuals screened (95% CI: 2.22–6.53). In logistic regression analysis, those with cough and at least one other symptom had an increased probability of testing positive compared to persons with symptoms other than cough. Whole-genome-sequencing demonstrate two separate cases of transmission.

Discussion

To our knowledge this study reports first-time results of an active TB case finding strategy based on on-spot symptom screening using a smartphone application, followed by fast molecular test on collected sputum samples. Our preliminary findings reveal a post-entry screening prevalence rate of 396 per 100.000 individuals screened (95% CI: 2.22–6.53).