Tuberculosis in migrants - screening, surveillance and ethics

Active Case Finding for Tuberculosis in Migrants: a Systematic Review

Background

Active case finding (ACF) is an alternative strategy to accelerate the identification of TB cases among the migrant population.

Objective

This study aimed to synthesize the evidence for the effectiveness of ACF TB in migrants.

Methods

This study uses the PRISMA model as a method of searching for journal articles in the databases of Google Scholar, ProQuest, EBSCO, ScienceDirect, Elsevier, and PubMed, as well as other sources such as textbooks and reports from 2017 to 2021 with the keywords "tuberculosis" AND "active case finding" AND "migrant". The search revealed 371 articles, of which 26 met the criteria for further discussion.

Results

Most studies show that the TB incidence among migrants is higher than in the local population. Factors leading to increased cases include lack of knowledge about the symptoms, high mobilization, social isolation, economic problems, and medication adherence that impact an advanced stage. Furthermore, it is also influenced by the low quality of health services, including accessibility, health facilities, health workers, and information. Therefore, Active Case Finding (ACF) is more effective in identifying cases of TB in the risk groups. This was conducted on migrants with increased notifications followed up with treatment.

Conclusion

ACF is effective approach in screening and diagnosing TB in the migrant group.

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.

Detecting Mycobacterium tuberculosis Infection in Children Migrating to Australia

In 2015, Australia updated premigration screening for tuberculosis (TB) disease in children 2-10 years of age to include testing for infection with Mycobacterium tuberculosis and enable detection of latent TB infection (LTBI). We analyzed TB screening results in children <15 years of age during November 2015-June 2017. We found 45,060 child applicants were tested with interferon-gamma release assay (IGRA) (57.7% of tests) or tuberculin skin test (TST) (42.3% of tests). A total of 21 cases of TB were diagnosed: 4 without IGRA or TST, 10 with positive IGRA or TST, and 7 with negative results. LTBI was detected in 3.3% (1,473/44,709) of children, for 30 applicants screened per LTBI case detected. LTBI-associated factors included increasing age, TB contact, origin from a higher TB prevalence region, and testing by TST. Detection of TB and LTBI benefit children, but the updated screening program's effect on TB in Australia is likely to be limited.

Characterizing tuberculosis transmission dynamics in high-burden urban and rural settings

Mycobacterium tuberculosis transmission dynamics in high-burden settings are poorly understood. Growing evidence suggests transmission may be characterized by extensive individual heterogeneity in secondary cases (i.e., superspreading), yet the degree and influence of such heterogeneity is largely unknown and unmeasured in high burden-settings. We conducted a prospective, population-based molecular epidemiology study of TB transmission in both an urban and rural setting of Botswana, one of the highest TB burden countries in the world. We used these empirical data to fit two mathematical models (urban and rural) that jointly quantified both the effective reproductive number, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R$$\end{document}R, and the propensity for superspreading in each population. We found both urban and rural populations were characterized by a high degree of individual heterogeneity, however such heterogeneity disproportionately impacted the rural population: 99% of secondary transmission was attributed to only 19% of infectious cases in the rural population compared to 60% in the urban population and the median number of incident cases until the first outbreak of 30 cases was only 32 for the rural model compared to 791 in the urban model. These findings suggest individual heterogeneity plays a critical role shaping local TB epidemiology within subpopulations.

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

Introduction

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

Objective

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

Methods

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

Results

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

Conclusion

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

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.

Paediatric management of a tuberculosis outbreak in an Irish Direct Provision Centre

Direct Provision in Ireland provides basic needs of food and shelter to asylum seekers while their refugee status is processed. There are a number of issues associated with living conditions in these centres including overcrowding, nutrition and play facilities (1,2). This article outlines the protocol of contact tracing and management of latent tuberculosis infection in the paediatric setting after a confirmed adult case of tuberculosis within a Direct Provision centre in Ireland. This is a retrospective case series of 82 children living in the centre. Twenty-two children were deemed at risk of infection, all asymptomatic. Sixteen children (20%) were treated for possible latent tuberculosis infection with isoniazid for 6-9 months; compliance was good with no side effects reported. This article highlights the risk to vulnerable populations, especially children, when residing in Direct Provision facilities. Initial migrant screening on entry is essential, in addition to improving living conditions and time spent by families in this living environment.

Spatial clustering and temporal trend analysis of international migrants diagnosed with tuberculosis in Brazil

Background

Tuberculosis (TB) in migrants is of concern to health authorities worldwide and is even more critical in Brazil, considering the country´s size and long land borders. The aim of the study was to identify critical areas in Brazil for migrants diagnosed with TB and to describe the temporal trend in this phenomenon in recent years.

Methods

This is an ecological study that used spatial analysis and time series analysis. As the study population, all cases of migrants diagnosed with TB from 2014 to 2019 were included, and Brazilian municipalities were considered as the unit of ecological analysis. The Getis-Ord Gi* technique was applied to identify critical areas, and based on the identified clusters, seasonal-trend decomposition based on loess (STL) and Prais-Winsten autoregression were used, respectively, to trace and classify temporal trend in the analyzed series. In addition, several municipal socioeconomic indicators were selected to verify the association between the identified clusters and social vulnerability.

Results

2,471 TB cases were reported in migrants. Gi* analysis showed that areas with spatial association with TB in immigrants coincide with critical areas for TB in the general population (coast of the Southeast and North regions). Four TB clusters were identified in immigrants in the states of Amazonas, Roraima, São Paulo, and Rio de Janeiro, with an upward trend in most of these clusters. The temporal trend in TB in immigrants was classified as increasing in Brazil (+ 60.66% per year [95% CI: 27.21–91.85]) and in the clusters in the states of Amazonas, Roraima, and Rio de Janeiro (+1.01, +2.15, and + 2.90% per year, respectively). The cluster in the state of São Paulo was the only one classified as stationary. The descriptive data on the municipalities belonging to the clusters showed evidence of the association between TB incidence and conditions of social vulnerability.

Conclusions

The study revealed the critical situation of TB among migrants in the country. Based on the findings, health authorities might focus on actions in regions identified, stablishing an intensive monitoring and following up, ensuring that these cases concluded their treatment and avoiding that they could spread the disease to the other regions or scenarios. The population of migrants are very dynamic, therefore strategies for following up them across Brazil are really urgent to manage the tuberculosis among international migrants in an efficient and proper way.

Surveillance of tuberculosis and treatment outcomes following screening and therapy interventions among marriage-migrants and labor-migrants from high TB endemic countries in Taiwan

Background

Tuberculosis (TB) among migrants from high-risk countries and underling interventions were concerned for disease control. This study aimed to assess the TB trends among marriage-migrants with the 1–2-round vs. labor-migrants with the four-round TB screenings in the period of the first four post-entry years; pre-entry screenings by an initial chest X-ray (CXR) were conducted during 2012–2015, and a friendly treatment policy was introduced in 2014.

Methods

TB data of migrants during 2012–2015 were obtained from the National TB Registry Database and analyzed. The incidences, clinical characteristics, and treatment outcomes were assessed to explore the impact of underlying interventions.

Results

During post-entry 0–4 years, the TB incidence rates among marriage-migrants ranged 11–90 per 100,000 person-years, with 60.8% bacteria-positive and 28.2% smear-positive cases. Whereas among labor migrants, the incidence rates ranged 67–120 per 100,000 person-years, with 43.6% bacteria-positive and 13.7% smear-positive cases. All migrants originated from Southeast Asia following pre-entry health screening in 2012–2015. The TB cases among marriage-migrants were with a higher proportion of sputum-smear-positivity (SS+) (OR: 4.82, 95% CI [3.7–6.34]) and CXR cavitation (OR: 2.90, 95% CI [2.10–4.01]). Marriage-migrants with TB had treatment completion rate of >90%, which was above the WHO target. For labor-migrants with TB, when compared the period of post- vs. pre-implementation of the friendly therapy policy that eliminated compulsory repatriation, the overall treatment completion rate of those who stayed in Taiwan improved by 30.9% (95% CI [24.3–37.6]) vs. 6.7% (95% CI [3.8–9.7]), which exceeded a 4.88-fold (95% CI: 3.83–6.22) improvement. Additionally, the treatment initiation rate within 30 days of diagnosis for SS- TB and B- TB cases during post- vs. pre-implementation of the therapy policy was increased, that is, 77.1% vs. 70.9% (OR: 1.38, 95% CI [1.12–1.70]) and 78% vs. 77% (OR: 1.64, 95% CI [1.38–1.95]).

Conclusion

Multiple CXR screenings could identify more TB cases with sputum-smear-negativity (SS-) TB at the early-stage, introducing latent tuberculosis infection (LTBI) screening might save underlying efforts. For those labor-migrants with TB who stayed in the receiving country, the friendly TB therapy policy not only significantly improved the treatment completion but also the early treatment initiation.