Epidemiology of Tuberculosis in Immigrants in a Large City with Large-Scale Immigration (1991-2013)

Advancing tuberculosis management: the role of predictive, preventive, and personalized medicine

Tuberculosis is a major global health issue, with approximately 10 million people falling ill and 1.4 million dying yearly. One of the most significant challenges to public health is the emergence of drug-resistant tuberculosis. For the last half-century, treating tuberculosis has adhered to a uniform management strategy in most patients. However, treatment ineffectiveness in some individuals with pulmonary tuberculosis presents a major challenge to the global tuberculosis control initiative. Unfavorable outcomes of tuberculosis treatment (including mortality, treatment failure, loss of follow-up, and unevaluated cases) may result in increased transmission of tuberculosis and the emergence of drug-resistant strains. Treatment failure may occur due to drug-resistant strains, non-adherence to medication, inadequate absorption of drugs, or low-quality healthcare. Identifying the underlying cause and adjusting the treatment accordingly to address treatment failure is important. This is where approaches such as artificial intelligence, genetic screening, and whole genome sequencing can play a critical role. In this review, we suggest a set of particular clinical applications of these approaches, which might have the potential to influence decisions regarding the clinical management of tuberculosis patients.

Prevalence of tuberculosis and associated factors among presumptive TB refugees residing in refugee camps in Ethiopia

BACKGROUND

Tuberculosis (TB) causes significant morbidity and mortality in refugee populations. Although Ethiopia is the third largest refugee-hosting country in Africa, there is limited published data on the prevalence and associated factors of TB in refugees. The objective of this study was to estimate the prevalence of bacteriologically confirmed pulmonary TB (PTB) and explore associated factors in presumptive TB refugees residing in refugee camps in Ethiopia.

METHODS

A facility-based cross-sectional study was conducted between February and August 2021 in refugee camps in Ethiopia. Data were collected consecutively from 610 presumptive TB refugees who attended for TB diagnosis in selected refugee camp clinics in Ethiopia. A pre-tested questionnaire was used to collect data, and sputum samples were collected from eligible study participants. The Xpert Mycobacterium tuberculosis (MTB)/Rifampicin (RIF) assay was performed on direct spot sputum samples, whereas morning sputum samples were processed and inoculated for bacteriological culture using Mycobacterium Growth Indicator Tube (MGIT) and Lowsteen Jensen (LJ) methods. The statistical software package (STATA version 14) was used for statistical analysis. A logistic regression model was used for the evaluation of the association between bacteriologically confirmed TB cases and the associated factors. Descriptive statistics were used for the expression of the results, and statistical significance was assumed at p < 0.05.

RESULTS

Out of 610 study participants, more than half were female (54.9%), and the mean age was 37.9 years (SD, 16.64). The prevalence of bacteriologically confirmed PTB cases among refugees residing in refugee camps in Ethiopia was 13.3% (95% CI, 10.7-16.2%) using the Xpert MTB/RIF assay and/or culture. MTB was detected in 12.8% (95% CI, 10.2-15.7%) of the individuals using the Xpert MTB/RIF assay, while culture positivity was observed in 11.6% (95% CI, 9.2-14.5%). The multivariable logistic regression model showed South Sudan origins (adjusted odds ratio, AOR = 7.74; 95% CI, 3.05-19.64), age group, 19-38 years old (AOR = 5.66; 95% CI, 1.86-17.28), and male sex (AOR = 2.69; 95% CI, 1.58-4.56) were significantly associated with the bacteriologically confirmed TB among refugees residing in refugee camps in Ethiopia.

CONCLUSION

The prevalence of bacteriologically confirmed PTB among presumptive TB refugees residing in refugee camps in Ethiopia was high. The national TB program should strengthen TB prevention and control activities in the refugee camps of Ethiopia. Moreover, an active TB survey program should be implemented in refugee camps in Ethiopia.

Tuberculosis among refugees and migrant populations: Systematic review

Tuberculosis (TB) is an important cause of morbidity and mortality among refugees and migrant populations. These groups are among the most vulnerable populations at increased risk of developing TB. However, there is no systematic review that attempts to summarize TB among refugees and migrant populations. This study aimed to summarize evidence on the magnitude of TB among refugees and migrant populations. The findings of this review will provide evidence to improve TB prevention and control policies in refugees and migrants in refugee camps and in migrant-hosting countries. A systematic search was done to retrieve the articles published from 2014 to 2021 in English language from electronic databases. Key searching terms were used in both free text and Medical Subject Heading (MeSH). Articles which had reported the magnitude of TB among refugees and migrant populations were included in the review. We assessed the risk of bias, and quality of the included studies with a modified version of the Newcastle–Ottawa Scale (NOS). Included studies which had reported incidence or prevalence data were eligible for data synthesis. The results were shown as summary tables. In the present review, more than 3 million refugees and migrants were screened for TB with the data collection period between 1991 and 2017 among the included studies. The incidence and prevalence of TB ranged from 19 to 754 cases per 100,000 population and 18.7 to 535 cases per 100,000 population respectively among the included studies. The current findings show that the most reported countries of origin in TB cases among refugees and migrants were from Asia and Africa; and the incidence and prevalence of TB among refugees and migrant populations is higher than in the host countries. This implies the need to implement and improve TB prevention and control in refugees and migrant populations globally.

Trial registration: The protocol of this review was registered on PROSPERO (International prospective register of systematic reviews) with ID number, CRD42020157619.

Tuberculosis and Migrant Pathways in an Urban Setting: A Mixed-Method Case Study on a Treatment Centre in the Lisbon Metropolitan Area, Portugal

Tuberculosis (TB) is an infectious disease associated with poverty. In the European Union TB tends to concentrate in urban settings. In Lisbon, previous studies revealed, the presence of migrant populations from a high endemic country, is one of the risk factors contributing to TB. To better understand TB in foreign-born individuals in the Lisbon Metropolitan Area, a mixed-method case study was undertaken on a TB treatment centre in a high-risk part of urban Portugal. Quantitatively, annual TB cases were analysed from 2008 to 2018, dividing foreign-origin cases into recent migrants and long-term migrants. Qualitatively, we explored recent migrants’ reasons, experiences and perceptions associated with the disease. Our results showed that foreign-born individuals accounted for 45.7% of cases, mainly originated from Angola, Guinea-Bissau, and Cabo Verde. TB in recent migrants increased over the years for Angola and Guinea-Bissau, while for Cabo Verde TB cases were due to migrants residing in Portugal for more than 2 years. Recent migrants’ reasons to travel to Portugal were to study, to live and work, tourism, and seeking better healthcare. Visiting family and friends, historical links and common language were key drivers for the choice of country. Recent migrants and long-term migrants may present distinct background profiles associated with diagnosed TB.

Gender differences in tuberculosis incidence rates-A pooled analysis of data from seven high-income countries by age group and time period

Introduction

Gender differences in the incidence rates for tuberculosis are occasionally reported. However, the magnitude and consistency of the differences by age group, among different populations, and over extended periods of time are not clear.

Materials and methods

We obtained national data from seven countries from open-access internet sites or personal communications with official representatives. We computed the male-to-female incidence rate ratios (IRRs) by country and year for every age group and pooled these ratios using meta-analytic methods. Meta-regression analysis was performed to estimate the contribution of age, country, and calendar years to the variation in the IRRs.

Results

In the age groups of < 1, 1-4, 5-9, and 10-14, the pooled male-to-female IRRs (with 95% CI) were as follows: 1.21 (1.05, 1.40), 0.99 (0.95, 1.04), 1.01 (0.96, 1.06), and 0.83 (0.77, 0.89), respectively. In the age groups 15-44, 45-64, and 65+ years, incidence rates were significantly higher in men, with IRRs of 1.25 (1.16, 1.35), 1.79 (1.56, 2.06), and 1.81 (1.66, 1.96), respectively. Meta-regression analysis revealed that age significantly contributed to the variation in the IRRs.

Conclusions

There were gender differences in the incidence rates for tuberculosis, with higher rates in boys aged less than one, no significant differences in boys of ages 1-9, and higher rates in boys/men older than 15. The only excess in female gender was in the age group 10-14 years. The age-related gender differences in tuberculosis incidence rates observed over several countries indicate the importance of including sex as a biological variable when assessing the risk factors for tuberculosis.

Whole genome sequencing-based analysis of tuberculosis (TB) in migrants: rapid tools for cross-border surveillance and to distinguish between recent transmission in the host country and new importations

Background

The analysis of transmission of tuberculosis (TB) is challenging in areas with a large migrant population. Standard genotyping may fail to differentiate transmission within the host country from new importations, which is key from an epidemiological perspective.

Aim

To propose a new strategy to simplify and optimise cross-border surveillance of tuberculosis and to distinguish between recent transmission in the host country and new importations

Methods

We selected 10 clusters, defined by 24-locus mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR), from a population in Spain rich in migrants from eastern Europe, north Africa and west Africa and reanalysed 66 isolates by whole-genome sequencing (WGS). A multiplex-allele-specific PCR was designed to target strain-specific marker single nucleotide polymorphisms (SNPs), identified from WGS data, to optimise the surveillance of the most complex cluster.

Results

In five of 10 clusters not all isolates showed the short genetic distances expected for recent transmission and revealed a higher number of SNPs, thus suggesting independent importations of prevalent strains in the country of origin. In the most complex cluster, rich in Moroccan cases, a multiplex allele-specific oligonucleotide-PCR (ASO-PCR) targeting the marker SNPs for the transmission subcluster enabled us to prospectively identify new secondary cases. The ASO-PCR-based strategy was transferred and applied in Morocco, demonstrating that the strain was prevalent in the country.

Conclusion

We provide a new model for optimising the analysis of cross-border surveillance of TB transmission in the scenario of global migration.

Tuberculosis infection and epidemiological characteristics in Haidian District, Beijing, 2005-2018

BACKGROUND

This study was aimed to investigate the epidemiological characteristic of pulmonary tuberculosis (PTB) in Haidian District, Beijing from 2005 to 2018 and to provide suggestions for controlling tuberculosis (TB) development.

METHODS

Epidemiological data about TB were obtained by the Infectious Disease Reporting System at different levels of medical institutions in Haidian District of Beijing from 2005 to 2018. The epidemiological methods combined with χ² test were used to analyze the distribution of TB in population, time, region and TB diagnosis.

RESULTS

In total, 14,449 cases of TB patients were reported in Haidian District from 2005 to 2018 and the average annual morbidity was 31.67/10,000. Of the total cases, housework and unemployed people (20.73%; 2996/14,449) accounted for the highest proportion of occupational distribution, followed by students, accounting for 17.18% (2482/14,449). 2433 patients with the age of 65 years and over accounting for 16.83% (2433/14,449); Laboratory confirmed diagnosis of TB was 26.60% and the diagnostic delays accounted for 54.96%.

CONCLUSIONS

From 2005 to 2018, TB incidence was falling gradually in Haidian District. However, particular attention should be paid to the elderly and student groups, and the policy publicity and education should be strengthened to reduce the diagnosis delay of TB.

Community strategies to tackle tuberculosis according to the WHO region of origin of immigrant communities

Setting: Tuberculosis (TB) control requires the proper identification and treatment of affected patients and investigation of their contacts. In certain vulnerable immigrant groups, however, these tasks may be hindered due to their ethnic and sociocultural characteristics. Objective: To analyse the results of a community programme designed to locate hard-to-reach immigrants with TB. Design: Descriptive study of all cases diagnosed with confirmed TB referred to the Public and Community Health team of the Drassanes International Health Unit in Barcelona during 2012-2014 due to difficulties in tracing these patients. Both cases and contacts were categorised based on their World Health Organization region of origin. The sociodemographic characteristics of each group and the community interventions carried out during the tracing period are described. Results: A total of 122 cases and 316 contacts were detected. As a result of community-based strategies, 73% of the initial cases completed treatment; 3.8% of the contacts were diagnosed with TB, 91.7% of whom were treated appropriately; 17.1% contacts had latent infection, 79.3% of whom completed chemoprophylaxis. Conclusions: Intervention strategies with a community approach for follow-up and control of TB in certain immigrant communities seem to be effective.

Prevalence of reactivity to the tuberculin test and associated factors in the population attended at a drug addiction center in the period 2013-2016

OBJECTIVE

Epidemiological study of prevalence, carried out at Center for Drug Addiction of the center of addictions of Nou Barris (Barcelona, Spain) during 2013-2016 in order to know the prevalence of tuberculin test reactivity (TTR) and its predictive factors in drug-dependent population.

MATERIAL AND METHODS

Epidemiological and clinical variables, associated with the consumption of drugs and the practice of the tuberculin test, were collected. The reading rate and the prevalence of TTR for annual periods, as well as the predictive factors through a bivariate and multivariate logistic regression analysis.

RESULTS

389 patients were studied (109 in 2013, 84 in 2014, 111 in 2015 and 85 in 2016) and they went to the reading of the TT 337 (86.6%). The prevalence of TTR was 33.2% in the readings. At the bivariate level, TTR was associated with sex, origin and prior history. In the multivariate analysis, the predictive value of age was confirmed (more reactivity in ≥40 years; p <0.001, odds ratio [OR]: 4.85, confidence interval [IC]: 2.68-8.78), being male (p = 0.003, OR: 2.81, IC: 1.43-5.53), and being an immigrant (p <0.001; OR: 7.32, IC: 3.56-15.03).

DISCUSSION

It is concluded that the prevalence of TTR is high, especially in men, in those of more age, and in immigrants and that the drug addiction devices continue to be basic in the detection and monitoring of the latent tuberculosis infection.

Tuberculosis and immigration

Tuberculosis continues to be a major public health problem in Spain. The incidence of tuberculosis in the native population has declined steadily in recent years. Migration flows have changed drastically since the beginning of the 21st century, with Spain becoming a recipient country for immigrants. Because most of the immigrants comes from countries with high incidence of tuberculosis, the contribution of the migrant population to new cases of tuberculosis is higher in relative terms than its weight in the total population. Tuberculosis programs must address the cultural, economic and medical aspects of the disease, and particularly target groups at risk, including the migrant population. In this paper, we will review the epidemiology and dynamics of tuberculosis in the migrant population, their differentiating clinical characteristics and the programmatic actions to address the problem.