Yield of chest X-ray tuberculosis screening of immigrants during the European refugee crisis of 2015: a single-centre experience

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.

Number needed to screen for TB in clinical, structural or occupational risk groups

BACKGROUND: Screening for active TB using active case-finding (ACF) may reduce TB incidence, prevalence, and mortality; however, yield of ACF interventions varies substantially across populations. We systematically reviewed studies reporting on ACF to calculate the number needed to screen (NNS) for groups at high risk for TB.METHODS: We conducted a literature search for studies reporting ACF for adults published between November 2010 and February 2020. We determined active TB prevalence detected through various screening strategies and calculated crude NNS for - TB confirmed using culture or Xpert^® MTB/RIF, and weighted mean NNS stratified by screening strategy, risk group, and country-level TB incidence.RESULTS: We screened 27,223 abstracts; 90 studies were included (41 in low/moderate and 49 in medium/high TB incidence settings). High-risk groups included inpatients, outpatients, people living with diabetes (PLWD), migrants, prison inmates, persons experiencing homelessness (PEH), healthcare workers, and miners. Screening strategies included symptom-based screening, chest X-ray and Xpert testing. NNS varied widely across and within incidence settings based on risk groups and screening methods. Screening tools with higher sensitivity (e.g., Xpert, CXR) were associated with lower NNS estimates.CONCLUSIONS: NNS for ACF strategies varies substantially between adult risk groups. Specific interventions should be tailored based on local epidemiology and costs.

Descriptive study of chest x-ray examination in mandatory annual health examinations at the workplace in Japan

The utility of chest x-ray examination (CXR) in mandatory annual health examinations for occupational health is debatable in Japan. This study aimed to provide basic data to consider future policies for mandatory annual health examinations in the workplace. A nationwide descriptive survey was performed to determine the rate of detection of tuberculosis, lung cancer, and other diseases through CXR in organizations associated with National Federation of Industrial Health Association. The rate of finding on CXR conducted during annual health examinations in FY2016 was evaluated. Data regarding diagnosis based on follow-up examination findings were obtained and compared with the national statistics. In addition, CXR findings were compared with the results of low-dose lung computed tomography performed at the Hitachi Health Care Center. From 121 surveyed institutions, 88 institutions with 8,669,403 workers were included. For all ages, 1.0% of examinees required follow-up examination. Among 4,764,985 workers with diagnosis data, the tuberculosis detection rate was 1.8–5.3 per 100,000 persons. For Lung cancer, 3,688,396 workers were surveyed, and 334 positive cases were detected. The lung cancer detection rate using CXR was 9.1–24.4 per 100,000 persons. From 164 cases with information regarding the clinical stage, 72 (43.9%) had Stage I lung cancer. From 40,045 workers who underwent low-dose computed tomography multiple times, 31 lung cancer cases, all with Stage I disease, were detected (detection rate: 77.4 per 100,000 persons). Our findings suggest that CXR plays a little role in the detection of active tuberculosis. With regard to LC screening, the detection rate of LC by CXR was lower, approximately 50%, than the expected rate (41.0 per 100,000 persons) of LC morbidity based on the age–sex distribution of this study population. However, the role of CXR for LC screening cannot be mentioned based on this result, because assessment of mortality reduction is essential to evaluate the role.

Active case finding of pulmonary TB in a European refugee camp: lessons learnt from Oinofyta hosting site in Greece

OBJECTIVES

To report on an active case finding (ACF) intervention that took place in the migrant camp of Oinofyta, Greece, upon suspicion of active TB transmission.

METHODS

Upon diagnosis of 3 TB cases among camp residents, an ACF intervention among contacts was implemented. All camp residents were offered two-step screening, that is tuberculin skin testing (TST) followed by chest X-ray in case of positive TST (defined as ≥5 mm).

RESULTS

336 of 379 (89%) camp residents underwent TST testing, of whom 110 (33%) exhibited a positive skin reaction. The rate of positive TST results was particularly high in the elderly and significantly higher in adults than in children. Differences by sex or nationality were not observed. Of the 110 cases with positive TST, only 75 underwent chest X-ray, resulting in the detection of one pulmonary TB case in an adult woman.

CONCLUSIONS

In the given intervention context, two-step ACF proved to be operationally cumbersome, with many residents lost to follow-up and a high Number Needed to Screen. Simpler ACF designs should be pilot-tested in similar settings in the future, and blanket screening of all camp residents should be reconsidered. Conclusions drawn by these exercises should pave the way for adopting a comprehensive, context-specific and evidence-based national strategy on TB in migrants.

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.

Tuberculosis screening during the 2015 European refugee crisis

Background

The purpose of our study was to describe and evaluate management, performance and results of Tuberculosis (TB)-screening among refugees and asylum seekers in a rural area in Germany in 2015.

Methods

Refugees or asylum seekers, staying in shared-accommodation are obligated to participate on screening chest X-ray (CXR) in order to screen for signs of potentially infectious pulmonary TB (German Protection against Infection Act and German Asylum Procedure Act). n = 705 individuals underwent screening chest X-ray (CXR) to detect pulmonary TB in September and October 2015 on site. One experienced radiologist interpreted and reported each CXR within 24 h after the enrollment in the screening program and results were sent to the local Public Health Department for potential further medical care. Image abnormalities suggestive for TB were defined according to established radiographic criteria such as pleural effusion, cavitation, consolidation, fibrous scarring or calcification. Only in case of TB-suggestive findings on CXR, further diagnostics were arranged (pulmonological examination, follow-up CXR, sputum culture, interferon-gamma release assay, bronchoscopy). Follow-up data was collected in collaboration with the local Public Health Department. Descriptive statistics were calculated using GraphPad Prism software.

Results

n = 637 CXR examinations (90%) did not show abnormal findings, n = 54 CXR (8%) showed incidental findings, and n = 14 CXR (2%) were suspicious for acute TB. Of these, n = 14 individuals, eight underwent further TB diagnostics. Active TB was confirmed in one individual (0.001% of the screening cohort).

Conclusions

Our cohort reflects current immigrations statistics in Europe and illustrates an overall low TB prevalence amongst individuals entering Germany in 2015. However, our findings support the improvement of diagnostic algorithms.

How effective are approaches to migrant screening for infectious diseases in Europe? A systematic review

Rates of migration to Europe, and within Europe, have increased in recent years, with considerable implications for health systems. Migrants in Europe face a disproportionate burden of tuberculosis, HIV, and hepatitis B and C, yet experience a large number of barriers to accessing statutory health care on arrival. A better understanding of how to deliver effective and cost-effective screening, vaccination, and health services to this group is now crucial. We did a systematic review to document and assess the effectiveness and cost-effectiveness of approaches used for infectious diseases screening, and to explore facilitators and barriers experienced by migrants to accessing screening programmes. Following PRISMA guidelines, we searched Embase, PubMed, PsychINFO, the Cochrane Library, and Web of Science (1989 to July 1, 2015, updated on Jan 1, 2018), with no language restrictions, and systematically approached experts across the European Union (EU) for grey literature. Inclusion criteria were primary research studies assessing screening interventions for any infectious disease in the migrant (foreign-born) population residing in EU or European Economic Area (EEA) countries. Primary outcomes were the following effectiveness indicators: uptake of screening, coverage, infections detected, and treatment outcomes. Of 4112 unique records, 47 studies met our inclusion criteria, from ten European countries (Belgium, Denmark, France, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the UK) encompassing 248 402 migrants. We found that most European countries screening migrants focus on single diseases only-predominantly active or latent tuberculosis infection-and specifically target asylum seekers and refugees, with 22 studies reporting on other infections (including HIV and hepatitis B and C). An infection was detected in 3·74% (range 0·00-95·16) of migrants. Latent tuberculosis had the highest prevalence across all infections (median 15·02% [0·35-31·81]). Uptake of screening by migrants was high (median 79·50% [18·62-100·00]), particularly in primary health-care settings (uptake 96·77% [76·00-100·00]). However, in 24·62% (0·12-78·99) of migrants screening was not completed and a final diagnosis was not made. Pooled data highlight high treatment completion in migrants (83·79%, range 0·00-100·00), yet data were highly heterogeneous for this outcome, masking important disparities between studies and infections, with only 54·45% (35·71-72·27) of migrants with latent tuberculosis ultimately completing treatment after screening. Coverage of the migrant population in Europe is low (39·29% [14·53-92·50]). Data on cost-effectiveness were scarce, but suggest moderate to high cost-effectiveness of migrant screening programmes depending on migrant group and disease targeted. European countries have adopted a variety of approaches to screening migrants for infections; however, these are limited in scope to single diseases and a narrow subset of migrants, with low coverage. More emphasis must be placed on developing innovative and sustainable strategies to facilitate screening and treatment completion and improve health outcomes, encompassing multiple key infections with consideration given to a wider group of high-risk migrants. Policy makers and researchers involved with global migration need to ensure a longer-term view on improving health outcomes in migrant populations as they integrate into health systems in host countries.

Diagnosis of Tuberculosis Using Colorimetric Gold Nanoparticles on a Paper-Based Analytical Device

We have developed a colorimetric sensing strategy employing gold nanoparticles and a paper-based analytical platform for the diagnosis of tuberculosis (TB). By utilizing the surface plasmon resonance effect, we were able to monitor changes in the color of a gold nanoparticle colloid based on the effects of single-stranded DNA probe molecules hybridizing with targeted double-stranded TB DNA. The hybridization event changes the surface charge density of the nanoparticles, causing them to aggregate to various degrees, which modifies the color of the solution in a manner that can be readily measured to determine the concentration of the targeted DNA analyte. In order to adapt this TB diagnosis method to resource-limited settings, we extended this label-free oligonucleotide and unmodified gold nanoparticle solution-based technique to a paper-based system that can be measured using a smartphone to obtain rapid parallel colorimetric results with low reagent consumption and without the need for sophisticated analytical equipment. In this study, we investigated various assay conditions, including the denaturing temperature and time, different oligonucleotide probe sequences, as well as the ratio of single stranded probe and double stranded target DNA. After optimizing these variables, we were able to achieve a detection limit of 1.95 × 10^-2 ng/mL for TB DNA. Furthermore, multiple tests could be performed simultaneously with a 60 min turnaround time.