Tuberculosis screening in migrant reception centers: results of a 2009 Italian survey

Factors associated with latent tuberculosis among international migrants in Brazil: a cross-sectional study (2020)

BACKGROUND

Migrants are a high priority group for TB control measures due to their high exposure to risk factors such as poverty and social vulnerability. The study aimed to identify factors associated with latent TB among international migrants living in four Brazilian state capitals. This was a cross-sectional study conducted in September and October 2020 in a sample of 903 international migrants living in four Brazilian state capitals: Boa Vista/RR (458), Manaus/AM (136), São Paulo/SP (257), and Curitiba/PR (52). Data were collected with a questionnaire consisting of open and closed questions on personal characteristics, information on TB, and use of preventive measures. Tuberculin skin test (TST) was performed, with reading after 72 h by trained nurses and using 5 mm induration as the positive cutoff. Chi-square test (X2) and Fisher's exact test, both two-tailed, were used to compare statistically significant levels of association between the migrants´ sociodemographic characteristics, vulnerability, and latent TB infection (LTBI). Binary logistic regression was applied to calculate odds ratios and respective 95% confidence intervals. For all the tests, type I error of 5% was defined as statistically significant (p < 0.05).

RESULTS

Prevalence of LTBI among migrants was 46.1% in Manaus/AM, 33.3% in São Paulo/SP, 28.1% in Curitiba/PR, and 23.5% in Boa Vista/RR. Factors associated with latent infection were age, male gender, and brown or indigenous race.

CONCLUSIONS

The study showed high prevalence of latent TB among international 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 infection in under-2-year-old refugees: Should we be screening? A systematic review and meta-regression analysis

AIM

Refugees are at increased risk of tuberculosis infection due to time spent in crowded camps, decreased nutrition and originating from countries whose own tuberculosis control systems may have been disturbed. In Australia, tuberculosis is screened for in for all refugees aged 11-34 years old and in those aged 2-10 years arriving from high-incidence countries. Our aims were to determine if refugee children aged under 2 years of age should also be screened.

METHODS

A systematic literature review and meta-regression was carried out on studies in refugee children under 18 years old, involving screening for tuberculosis (active or latent tuberculosis infection (LTBI)). Studies were extracted from the last 10 years from a range of bibliographic databases using the search terms 'tuberculosis', 'children', 'screening' and 'refugee', which tested for tuberculosis using the tuberculin skin test (TST) or QuantiFERON-Gold (Interferon Gamma Release Assay (IGRA)).

RESULTS

Of the 15 included studies, prevalence of LTBI in < 2-year-olds was 5% using IGRA and 15% using TST (P < 0.05). Prevalence increased with age (odds ratio 1.12; 95% confidence interval: 1.06-1.17) cumulatively and decreased where IGRA was used for screening compared to TST (odds ratio 0.38; 95% confidence interval: 0.25-0.58). Prevalence of LTBI did not differ between general versus clinic refugee cohorts.

CONCLUSIONS

Refugees are a particularly vulnerable group in their susceptibility to tuberculosis, and LTBI management is a critical part of tuberculosis disease control due to the lifetime risk of developing active tuberculosis. A prevalence of 5-15% for LTBI in the under 2 years age group would support them being included in screening programmes.

Radiological Signs of Latent Tuberculosis on Chest Radiography: A Systematic Review and Meta-Analysis

Objective

Current guidelines recommend screening for latent tuberculosis infection (LTBI) with a tuberculin skin test (TST) or interferon gamma release assay (IGRA), or both. Many also recommend chest radiography (CXR), although its added value is uncertain. This systematic review assessed the prevalence of abnormalities suggestive of LTBI on CXR (LTBI-CXR lesions) and evaluated the strength of the association.

Method

We searched 4 databases up to September 2017 and systematically reviewed cross-sectional and cohort studies reporting LTBI-CXR lesions in individuals with a positive TST or IGRA, or both, result. Prevalence estimates were pooled using random effects models and odds ratios (ORs) were used to calculate risk estimates.

Results

In the 26 included studies, the pooled proportion of individuals with LTBI having LTBI-CXR lesions was 0.15 (95% confidence interval [CI], 0.12–0.18]. In 16 studies that reported on individuals with LTBI and uninfected controls, LTBI-CXR lesions were associated with a positive TST result ≥ 5 mm or ≥ 10 mm (OR, 2.45; 95% CI, 1.00–5.99; and OR, 2.06; 95% CI, 1.38–3.09, respectively) and with a positive QuantiFERON result (OR, 1.99; 95% CI, 1.17–3.39) compared to CXR in uninfected controls. Although few studies reported specified lesions, calcified nodules were most frequently reported in individuals with LTBI (proportion, 0.07; 95% CI, 0.02–0.11).

Conclusions

Lesions on CXR suggestive of previous infection with Mycobacterium tuberculosis were significantly associated with positive tests for LTBI, although the sensitivity was only 15%. This finding may have added value when detection of past LTBI is important but immunodiagnostic tests may be unreliable.

Migration-related tuberculosis: epidemiology and characteristics of tuberculosis cases originating outside the European Union and European Economic Area, 2007 to 2013

Migrants arriving from high tuberculosis (TB)-incidence countries may pose a significant challenge to TB control programmes in the host country. TB surveillance data for 2007-2013 submitted to the European Surveillance System were analysed. Notified TB cases were stratified by origin and reporting country. The contribution of migrant TB cases to the TB epidemiology in EU/EEA countries was analysed. Migrant TB cases accounted for 17.4% (n = 92,039) of all TB cases reported in the EU/EEA in 2007-2013, continuously increasing from 13.6% in 2007 to 21.8% in 2013. Of 91,925 migrant cases with known country of origin, 29.3% were from the Eastern Mediterranean, 23.0% from south-east Asia, 21.4% from Africa, 13.4% from the World Health Organization European Region (excluding EU/EEA), and 12.9% from other regions. Of 46,499 migrant cases with known drug-susceptibility test results, 2.9% had multidrug-resistant TB, mainly (51.7%) originating from the European Region. The increasing contribution of TB in migrants from outside the EU/EEA to the TB burden in the EU/EEA is mainly due to a decrease in native TB cases. Especially in countries with a high proportion of TB cases in non-EU/EEA migrants, targeted prevention and control initiatives may be needed to progress towards TB elimination.

Active Tuberculosis Case Finding Interventions Among Immigrants, Refugees and Asylum Seekers in Italy

In Italy tuberculosis (TB) is largely concentrated in vulnerable groups such as migrants and in urban settings. We analyzed three TB case finding interventions conducted at primary centers and mobile clinics for regular/irregular immigrants and refugees/asylum seekers performed over a four-year period (November 2009-March 2014) at five different sites in Rome and one site in Milan, Italy. TB history and presence of symptoms suggestive of active TB were investigated by verbal screening through a structured questionnaire in migrants presenting for any medical condition to out-patient and mobile clinics. Individuals reporting TB history or symptoms were referred to a TB clinic for diagnostic workup. Among 6347 migrants enrolled, 891 (14.0%) reported TB history or symptoms suggestive of active TB and 546 (61.3%) were referred to the TB clinic. Of them, 254 (46.5%) did not present for diagnostic evaluation. TB was diagnosed in 11 individuals representing 0.17% of those screened and 3.76% of those evaluated. The overall yield of this intervention was in the range reported for other TB screening programs for migrants, although we recorded an unsatisfactory adherence to diagnostic workup. Possible advantages of this intervention include low cost and reduced burden of medical procedures for the screened population.

Screening for Infectious Diseases among Newly Arrived Migrants: Experiences and Practices in Non-EU Countries of the Mediterranean Basin and Black Sea

Changing migration dynamics in the Mediterranean Sea and differences in infectious diseases (ID) burden between the countries of origin have raised questions whether public health actions are needed to avoid the transmission of ID. Screening newly arrived migrants for ID is one health monitoring option, offering opportunities for prevention, early detection and treatment. The authors conducted a survey among country experts in non-European Union countries of the Mediterranean and Black Sea, in order to explore current ID screening practices and policies for newly arrived migrants. The association between the existence of guidelines and the proportion of refugees in the population was also estimated. Eighteen country experts responded (90%) out of the 20 invited. Eleven countries (61%) implemented screening programmes and six (38%) had national guidelines. Screening was performed most often for tuberculosis at the holding level. A higher proportion of refugees in the population was associated with the existence of guidelines for screening (p = 0.05). Fourteen experts (88%) considered screening among migrants useful. The results show that screening for ID in newly arrived migrants is relevant for non-EU countries of the Mediterranean and Black Sea. Common guidelines could be promoted focusing on both individual and public health benefits of screening programmes.

A systematic review on TST and IGRA tests used for diagnosis of LTBI in immigrants

BACKGROUND

High immigration rates from tuberculosis (TB) endemic countries to low-incidence countries have caused new TB guidelines in these countries to reconsider latent TB infection (LTBI) screening in these immigrants.

OBJECTIVES

We performed a systematic review with the primary outcome of evaluating the number of cases recommended LTBI treatment with the tuberculin skin test (TST) or interferon gamma release assay (IGRA). Secondary objectives were to examine prevalence of positive LTBI diagnostic tests stratified by age and incidence of TB in country of origin.

METHODS

We performed a systematic search of seven electronic databases for studies assessing TST and/or IGRA performance in immigrant populations to low incidence countries. Demographics, LTBI diagnosis, longitudinal TB development, and test result data were the primary data extracted from the studies. Prevalence of positive test data was stratified by age and country of origin. Studies were evaluated using a modified SIGN checklist for diagnostic studies. Data was compared using Fisher's exact test or χ (2) test, where appropriate.

RESULTS

Our literature search yielded 51 studies (n = 34 TST, n = 9 IGRA, n = 8 both). Recommendation of LTBI treatment was less common in those tested with an IGRA compared to TST (p < 0.0001), while long-term development of active TB appears higher in those with a positive IGRA. There was no difference in the sensitivity and specificity of the IGRA and TST for prevalent TB (p > 0.05). Prevalence of a positive test was significantly lower in those who were <18 years of age compared to those ≥18 years of age (p < 0.0001) and those from low TB incidence countries compared to high incidence countries (p < 0.0001) for both TST and IGRA. When comparing the two tests within the 2 subgroups: age and TB incidence in country of origin, the prevalence of positive results was significantly lower for the IGRA than the TST (p < 0.0001).

LIMITATIONS

The number of available studies evaluating the IGRA and longitudinal active TB development in those tested limits this study.

CONCLUSION

Prevalence of positive test results were significantly lower in immigrants who were tested with an IGRA, resulting in fewer immigrants being recommended for LTBI treatment compared to TST. Coupled with comparable performance for detecting prevalent TB cases, the IGRA appears to exhibit better specificity than the TST and may be preferred as the standard of care for detecting LTBI in immigrants moving to low TB incidence countries.

Towards a European Framework to Monitor Infectious Diseases among Migrant Populations: Design and Applicability

There are limitations in our capacity to interpret point estimates and trends of infectious diseases occurring among diverse migrant populations living in the European Union/European Economic Area (EU/EEA). The aim of this study was to design a data collection framework that could capture information on factors associated with increased risk to infectious diseases in migrant populations in the EU/EEA. The authors defined factors associated with increased risk according to a multi-dimensional framework and performed a systematic literature review in order to identify whether those factors well reflected the reported risk factors for infectious disease in these populations. Following this, the feasibility of applying this framework to relevant available EU/EEA data sources was assessed. The proposed multidimensional framework is well suited to capture the complexity and concurrence of these risk factors and in principle applicable in the EU/EEA. The authors conclude that adopting a multi-dimensional framework to monitor infectious diseases could favor the disaggregated collection and analysis of migrant health data.

Higher Rate of Tuberculosis in Second Generation Migrants Compared to Native Residents in a Metropolitan Setting in Western Europe

BACKGROUND

In Western Europe, migrants constitute an important risk group for tuberculosis, but little is known about successive generations of migrants. We aimed to characterize migration among tuberculosis cases in Berlin and to estimate annual rates of tuberculosis in two subsequent migrant generations. We hypothesized that second generation migrants born in Germany are at higher risk of tuberculosis compared to native (non-migrant) residents.

METHODS

A prospective cross-sectional study was conducted. All tuberculosis cases reported to health authorities in Berlin between 11/2010 and 10/2011 were eligible. Interviews were conducted using a structured questionnaire including demographic data, migration history of patients and their parents, and language use. Tuberculosis rates were estimated using 2011 census data.

RESULTS

Of 314 tuberculosis cases reported, 154 (49.0%) participated. Of these, 81 (52.6%) were first-, 14 (9.1%) were second generation migrants, and 59 (38.3%) were native residents. The tuberculosis rate per 100,000 individuals was 28.3 (95CI: 24.0-32.6) in first-, 10.2 (95%CI: 6.1-16.6) in second generation migrants, and 4.6 (95%CI: 3.7-5.6) in native residents. When combining information from the standard notification variables country of birth and citizenship, the sensitivity to detect second generation migration was 28.6%.

CONCLUSIONS

There is a higher rate of tuberculosis among second generation migrants compared to native residents in Berlin. This may be explained by presumably frequent contact and transmission within migrant populations. Second generation migration is insufficiently captured by the surveillance variables country of birth and citizenship. Surveillance systems in Western Europe should allow for quantifying the tuberculosis burden in this important risk group.

Health profile and disease determinants among asylum seekers: a cross-sectional retrospective study from an Italian reception centre

BACKGROUND

Data on diseases' determinants and health status of asylum seekers (ASs) are limited.

METHODS

We performed a cross-sectional retrospective study in a large ASs centre in Italy. Data were collected during a 1-year period. Descriptive statistics were calculated. A χ(2) test was used to assess the association between socio-demographics characteristics of ASs and screening test results. A multiple logistic regression analysis was performed to identify diseases' predictors by using ICD-10 diagnoses classification as outcome variable, socio-demographic characteristics as independent variable and visits' number as confounding variable.

RESULTS

Overall, data on 792 ASs (mean age 27 years, 80% males, 58% from Africa) were assessed, 43% underwent voluntary infectious diseases screening and 2843 diagnoses were recorded. The most frequent diagnoses were: respiratory diseases, symptoms/signs not elsewhere classified, digestive diseases and infectious diseases. Gender was the most frequent predictor of ICD-10 diagnoses, while African origin, civil status and education were, respectively, predictive of cardiovascular and infectious diseases, genitourinary diseases and pregnancy-related disorders. Higher mean age was associated with syphilis, HIV and HCV infection and African origin with HIV infection.

CONCLUSIONS

Communicable diseases were not prevalent in the ASs population we analysed. A stronger cultural mediation support is needed to facilitate prevention, access and continuity of care for ASs.

Screening for infectious diseases among newly arrived migrants in EU/EEA countries--varying practices but consensus on the utility of screening

Screening is one possible tool for monitoring infectious diseases among migrants. However, there is limited information on screening programmes targeted for newly arrived migrants in EU/EEA countries. Our aim was to investigate the implementation, practices and usefulness of these programmes. We conducted a survey among country experts from EU/EEA countries and Switzerland, asking whether their countries had implemented screening programmes. We also estimated the association between the implementation of these programmes and the rate of asylum-seekers in the population. Of the countries, 16 (59%) had implemented screening programmes and 15 (56%) had national guidelines. The rate of asylum-seekers was associated with implementation of screening programmes (p = 0.014). Screening was performed most often for tuberculosis; most commonly on holding level, and was targeted to specific migrant groups in over half of the countries performing screening. Twenty-five of all the country experts (96%) considered screening among migrants useful, and 24 (92%) would welcome EU level guidelines for screening. The implementation of screening programmes varied, and the practices were different among countries. Our survey suggests, that establishing EU level guidelines for screening would be useful, although they would have to take into account differences between individual countries.

To x-ray or not to x-ray? Screening asymptomatic children for pulmonary TB: a retrospective audit

OBJECTIVE

Recent studies found that a chest x-ray (CXR) has limited value in the assessment of asymptomatic adults with tuberculosis (TB) infection. We aimed to determine in asymptomatic children with a positive tuberculin skin test and/or interferon-γ release assay (TST/IGRA) whether a CXR identifies findings suggestive of pulmonary TB.

DESIGN, SETTING AND PATIENTS

All children with TB infection (defined as TST ≥10 mm and/or positive IGRA) presenting to The Royal Children's Hospital Melbourne during a 54-month period were included. All CXRs were reviewed by a senior radiologist blinded to the clinical details. The medical records of those with radiological abnormalities suggestive of TB were examined to identify those who were asymptomatic when the CXR was done. Demographical data were also collected.

RESULTS

CXRs were available for 268 of 330 TB-infected children, of whom 60 had CXR findings suggestive of TB. Of the 57 for whom clinical details were available, 26 were asymptomatic. Of these asymptomatic children with radiological abnormalities suggestive of TB, 6 had CXR findings suggestive of active TB, 14 had CXR findings suggestive of prior TB and 6 had isolated non-calcified hilar lymphadenopathy. The six with findings suggestive of active TB represented 2.6% (95% CI 0.9 to 5.5%) of asymptomatic TST/IGRA-positive children with evaluable CXRs. One child with isolated hilar lymphadenopathy had microbiologically-confirmed TB.

CONCLUSIONS

In contrast to the results from studies in adults, a CXR identified a small but noteworthy number of children with findings suggestive of pulmonary TB in the absence of clinical symptoms.